(Topic ID: 242472)

Bally Lost World - Bringing it back to Life


By MaxAsh

15 days ago



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  • 57 posts
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  • Latest reply 5 days ago by Quench
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SDB_TP3.jpg
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#1 15 days ago

Recently picked up a Lost World (Bally, 1978) that had been sitting around for 25-30 years not working. Overall nice condition after some cleanup. Of course, given the original MPU and battery sitting there for decades, it trashed the MPU perimeter (but nothing else from what I can tell). Testing shows that the MPU might actually be salvageable, but I'll worry about that later. I have a brand new MPU, so that's going in there for the time being. Here's where I am so far:

* Initially, just GI came on, but after some tinkering, I've seen some other signs of life.

* While doing some voltage testing the other day, the game suddenly semi-booted. Not sure why. The displays came on, game took credits, and when I attempted to start a game the scoring/switches worked (but solenoids all dead). I was able to drain 3 balls and go into Game Over/Match, and sounds were working.

* After unplugging the game for a day then plugging it back in, it went back to just GI and display glow, no booting, no Flashes from the MPU, no sounds.

Voltage Testing - Rectifier Board (all I've done is repin the J3 20-pin connector so far)

TP1 5.51 vdc
TP2 244 vdc
TP3 2.51 vdc ***
TP4 6.74 vac
TP5 44.0 vdc

*** Everything is within spec aside from TP3 (should be 11.9 vdc), which from my reading is used to obtain the regulated +5V for the game's logic circuits. When the game was temporarily booting, TP3 showed 14.0 vdc.

Testing at the Transformer on taps 15 & 16 (which feed the voltage for this area) I'm getting around 13.2vac, which is a little high (should be 12vac). Testing at the fuse I'm getting 13.2vac, and testing on the AC connection points of bridge rectifier BR2 I'm getting 13.2vac.

Based on all of this, it seems like the voltage is getting to BR2 (even though it's a little higher coming off the transformer than expected), but not reaching the TP3 with the proper ~11.9vdc expected. Does this mean BR2 is likely bad?

#2 15 days ago
Quoted from MaxAsh:

Testing at the Transformer on taps 15 & 16 (which feed the voltage for this area) I'm getting around 13.2vac, which is a little high (should be 12vac).

13.2VAC is fine.

What DC voltage do you read across the - and + pins of the BR2 bridge rectifier? Does it change if you disconnect J3 from the rectifier board?

#3 15 days ago
Quoted from Quench:

13.2VAC is fine.
What DC voltage do you read across the - and + pins of the BR2 bridge rectifier? Does it change if you disconnect J3 from the rectifier board?

Thank you for the reply! I believe the + and - pins read 2.51 vdc like the TP3 does, but I can double-check. Just so I'm clear what you're asking, you want me to leave J1/J2 connected, and disconnect J3, then test again?

#4 15 days ago
Quoted from MaxAsh:

Just so I'm clear what you're asking, you want me to leave J1/J2 connected, and disconnect J3, then test again?

Yep, you need J2 connected since your wall mains power goes through it to the transformer. J1 goes to the playfield - the output of BR2 doesn't go to the playfield so no need to disconnect it.

The point of disconnecting J3 off the rectifier board is to see if something downstream is loading down the BR2 bridge. Did you by any chance do any work on the solenoid driver board like change the large filter caps maybe?

#5 15 days ago
Quoted from Quench:

Did you by any chance do any work on the solenoid driver board like change the large filter caps maybe?

No work done as of yet on the other boards. I removed the corroded MPU for cleaning, etc., and replaced it with a new ultimate MPU I had. I did initial testing on the Rectifier and found that TP1 showed no voltage, and TP3 was incorrect/erratic as well. I noticed that J3 looked a little beat up so I started there and repinned it. This brought TP1 from no reading back to its proper voltage, but didn't fix TP3. I was going to repin J1 and J2 next, since that seemed to make sense as well.

#6 15 days ago

Time to do a diode test on BR2 (machine OFF). The bridge is basically four diodes - if you look at the rectifier board schematic, you can see how the "diodes" are wired.

#7 15 days ago
Quoted from Quench:

Time to do a diode test on BR2 (machine OFF). The bridge is basically four diodes - if you look at the rectifier board schematic, you can see how the "diodes" are wired.

Can I just test (machine off) using the solder points on the front of the board, or would it be best to just pull the whole board and test that way? Guessing I'm just checking to make sure the diodes are properly blocking and not shorted/failed?

EDIT: Found this to answer that question: http://www.pinwiki.com/wiki/index.php?title=General#Testing_a_Bridge_Rectifier will do

LostWorld_BR2 (resized).jpg

#8 15 days ago
Quoted from MaxAsh:

Can I just test (machine off) using the solder points on the front of the board

Yes, test BR2 using the solder points on the front of the board. Make sure J3 is disconnected so the meter results aren't affected by circuitry downstream.

Note FYI, BR1 and BR3 have ceramic resistors connected across them on the rectifier board so testing those two bridges in circuit in diode mode isn't so straight forward.

But BR2 can be tested in circuit no problems.

#9 15 days ago

Good info, thank you! Going to try it shortly and report back.

#10 15 days ago
Quoted from Quench:

Yes, test BR2 using the solder points on the front of the board. Make sure J3 is disconnected so the meter results aren't affected by circuitry downstream.

Okay, I performed additional testing. Note: I repinned J1 and J2, just in case. No change, but good to have them done.

I disconnected J3 and checked the test points again, here are the results:

TP1 0.00 vdc
TP2 180 vdc
TP3 12.5 vdc
TP4 7.19 vac
TP5 45.3 vdc

As you can see, the TP3 is now within range of where it should be, so I'm guessing that (as you noted) something is screwing it up downstream when J3 is connected.

I also noticed that TP1 had NO reading, and TP2 dropped 60-70vdc, but I assume that's normal with J3 disconnected? When I reconnected J3, TP1 and TP2 went back to normal/within spec, and TP3 dropped back to 2.51vdc again.

BR2 Testing

With the power off and J3 disconnected, I tested BR2. Results: all readings were between .526 and .528, which as I understand it from the instructions on pinwiki are within the .5-.7 range so they're good.

So... it seems like the next question is: What is causing TP3 to drop to 2.51vdc when J3 is connected to the rectifier board?

#11 15 days ago

TP1 shouldn't have read zero volts with J3 disconnected off the rectifier board. Maybe your meter didn't make good contact during that measurement.
TP2 voltage commonly appears lower when J3 is disconnected. It needs the solenoid driver board connected via J3 to give proper meter readings.

The output of BR2 goes to the MPU board (J4) and the solenoid driver board (J3).

Reconnect the rectifier board J3 connector. Disconnect the J3 connector off the solenoid driver board and remeasure TP3 on the rectifier board. If voltage is ok, suspect the C23 capacitor and/or the 5 volt regulator on the large heatsink on the solenoid driver board .

BTW, what fuse have you got in F3 on the rectifier board? (should be a 4 amp fast blow). I'm a little surprised it's not blowing.

#12 14 days ago

I woke up this morning and re-did the testing... now TP1 shows zero volts with J3 connected OR disconnected... that's not good, not sure what happened there. The voltage is still appearing on BR1 as it should, so that's odd. I tested the associated TP over on the solenoid driver and it's zero as well. Guess I can deal with that later... the +5vdc regulated on TP3 is probably more important right now anyway.

I pulled J3 off the solenoid driver board as suggested, and sure enough TP3 on the Rectifier is showing 12.26vdc, so it looks like you're correct, something on that driver board is likely the culprit.

F3 is a 4A fast blow (32V) probably original. Pulled it and tested it, looks good.

#13 14 days ago
Quoted from MaxAsh:

The voltage is still appearing on BR1 as it should, so that's odd.

Both the AC voltage input to the bridge and the DC voltage output of the BR1 bridge measured ok but TP1 measured zero volts?

Quoted from MaxAsh:

I tested the associated TP over on the solenoid driver and it's zero as well.

The 5.4V output of BR1 only goes to feature lamps - it's not connected to any other boards.

Quoted from MaxAsh:

I pulled J3 off the solenoid driver board as suggested, and sure enough TP3 on the Rectifier is showing 12.26vdc, so it looks like you're correct, something on that driver board is likely the culprit.

Can you post some clear pictures of the solenoid driver board and the rectifier board?
You can try unsoldering one of the wires connected to the large C23 capacitor on the solenoid driver board (to disconnect the capacitor). Reconnect J3 on the solenoid driver board and J3 on the rectifier board. Disconnect the MPU board J4 connector to isolate it away from power. Power up. If TP3 on the rectifier board now measures ok it might be the C23 capacitor at fault.

#14 14 days ago
Quoted from Quench:

Both the AC voltage input to the bridge and the DC voltage output of the BR1 bridge measured ok but TP1 measured zero volts?

The 5.4V output of BR1 only goes to feature lamps - it's not connected to any other boards.

Can you post some clear pictures of the solenoid driver board and the rectifier board?

Adding some pics as requested. Sorry for the angle and dirty look to things, the pic is a few days old.

Lost_World_Rec1 (resized).jpgLost_World_Rec2 (resized).jpgLost_World_Sol_Drive (resized).jpg
#15 13 days ago
Quoted from Quench:

You can try unsoldering one of the wires connected to the large C23 capacitor on the solenoid driver board (to disconnect the capacitor). Reconnect J3 on the solenoid driver board and J3 on the rectifier board. Disconnect the MPU board J4 connector to isolate it away from power. Power up. If TP3 on the rectifier board now measures ok it might be the C23 capacitor at fault.

I'll try this today and report back. Sadly, I don't have that capacitor on hand (closest I have is an 18,000uf one, which is too far off from what I need it seems). But I can at least try the test you suggested and see what happens. Everything is original in this thing, more or less, so it needs some upgrading for sure.

#16 13 days ago

Just make sure you screw the rectifier board back in. BR1 needs to be mounted to the metal plate to keep it cool. Note there is an intermediate aluminum block that sits between the bridges and the mounting metal plate. You can see it's fallen down in your second picture. If you have some heat transfer paste, apply some.

#17 13 days ago
Quoted from Quench:

Just make sure you screw the rectifier board back in. BR1 needs to be mounted to the metal plate to keep it cool. Note there is an intermediate aluminum block that sits between the bridges and the mounting metal plate. You can see it's fallen down in your second picture. If you have some heat transfer paste, apply some.

Will do, thanks. I only pulled it off to take a peek (and clean it up some). I have plenty of thermal paste from various computer and electronics stuff, so I'll put some fresh stuff on before reassembling. Though for a short voltage test, I guess I could leave it off temporarily. Just got home, I'll go take a look at all of this now.

#18 13 days ago

Just performed the suggested test (Disconnect one side of C23, remove J4 MPU, connect J3 on SD/Rectifier boards). No change... TP3 on rectifier still reading low (2.60vdc). Does that mean it's likely the 5V regulator to the right of C23 on the board?

#19 13 days ago
Quoted from MaxAsh:

Does that mean it's likely the 5V regulator to the right of C23 on the board?

Possibly.
With the machine OFF, disconnect J3 from the solenoid driver board (SDB). Use your multi-meter to measure the resistance between the metal case of the 5V regulator and TP5 on the SDB. You're effectively measuring if the 5V regulator input has some sort of short. If you have the C23 capacitor reconnected, the resistance will slowly rise over about a minute or so until the C23 cap charges. The final resistance reading when it steadies is the one to note.

#20 13 days ago
Quoted from Quench:

Possibly.
With the machine OFF, disconnect J3 from the solenoid driver board (SDB). Use your multi-meter to measure the resistance between the metal case of the 5V regulator and TP5 on the SDB. You're effectively measuring if the 5V regulator input has some sort of short. If you have the C23 capacitor reconnected, the resistance will slowly rise over about a minute or so until the C23 cap charges. The final resistance reading when it steadies is the one to note.

J3 disconnected from SDB, measured resistance from metal casing of regulator to TP5 = 1.359 on 2M setting after it settled and held.

#21 12 days ago

Those resistance readings look about right to me.

Somethings not right here. As I mentioned earlier, a load drop like that on the 12V line should be blowing the F3 fuse on the rectifier board.

The battery in your multi-meter isn't flat is it?
Where are you connecting the black meter lead as a ground reference point? Does this ground reference point measure zero ohms continuity to the earth prong on the power cable plug?

#22 12 days ago
Quoted from Quench:

The battery in your multi-meter isn't flat is it?
Where are you connecting the black meter lead as a ground reference point? Does this ground reference point measure zero ohms continuity to the earth prong on the power cable plug?

I can change the batteries in my meter, but all the other readings look good and test fine, so that would be an odd reason. I'll check themf though just in case.

I've used a couple of different ground spots just in case, and the readings are always the same. The most common ground I've been using lately is the leg of the big resistor on the rectifier, as suggested in the repair guides. All the other readings work fine with that so I'm guessing that's ok.

I'll check the ground resistance and continuity, but there's actually no ground prong on the plug, it's original I believe. There's a little ground wire hanging loose off the end. Wouldn't it be strange though if grounding was an issue for just the one vdc reading and okay for the others?

#23 12 days ago

Just picked up and fixed a Lost World myself recently. Look at all of the
connectors on the rectifier board. If the molex connectors show any
black areas, replace the pins. A very common problem on older
SS pins. In my case it was the pin that supplies unregulated
voltage to the 5v regulator.
Steve

#24 12 days ago

Hi Steve - I replaced all the connector pins, but not the headers as of yet. I don't have the proper size headers handy, but it wouldn't hurt to reflow/test them. On mine, the only pin/connector that appeared discolored was one of the GI related ones, but that doesn't mean the others don't need love too. That being said, since unplugging the connector on the SDB J3 corrects the TP3 voltage on the regulator as Quench noted, I'm guessing my issue is downstream. This is the kind of troubleshooting I struggle with sometimes. Much better when the fixes are clear cut!

Open to suggestions on what to try next

#25 12 days ago

Hook up J3 on the SDB again.
What voltage do you read between the ground leg of the big resistor on the rectifier board and the "GND" test point on the SDB?
What voltage do you read at test point TP5 on the SDB?
What voltage do you read at test point TP2 on the SDB?

[Edit] With the machine off, disconnect J4 from the MPU board and then power up. Measure the voltage at TP3 on the rectifier board The 12V supply also goes to the MPU board so let's see if it's related.

#26 12 days ago
Quoted from Quench:

Hook up J3 on the SDB again.
What voltage do you read between the ground leg of the big resistor on the rectifier board and the "GND" test point on the SDB?
What voltage do you read at test point TP5 on the SDB?
What voltage do you read at test point TP2 on the SDB?
[Edit] With the machine off, disconnect J4 from the MPU board and then power up. Measure the voltage at TP3 on the rectifier board The 12V supply also goes to the MPU board so let's see if it's related.

What voltage do you read between the ground leg of the big resistor on the rectifier board and the "GND" test point on the SDB? zero volts
What voltage do you read at test point TP5 on the SDB? 2.59 vdc
What voltage do you read at test point TP2 on the SDB? 199.8 vdc
J4 on MPU disconnect Measure the voltage at TP3 on the rectifier board 4.37 vdc (up from the 2.5 vdc with J4 connected)

Note this is a brand new ultimate MPU... but I have not repinned any of the connectors for the MPU yet. Not sure if that might be related.

#27 12 days ago
Quoted from MaxAsh:

J4 on MPU disconnect Measure the voltage at TP3 on the rectifier board 4.37 vdc (up from the 2.5 vdc with J4 connected)

The TP3 voltages you're getting are kind of floaty and the value isn't saying much.

Quoted from MaxAsh:

What voltage do you read at test point TP2 on the SDB? 199.8 vdc

Ugh, sorry I meant TP1 (5V output of the regulator), not TP2.

Have you got any 12 volt incandescent globes? Say something around 5 watts?
If yes, hookup some wires to it. Disconnect J3 from the rectifier board. Connect your multi-meter to ground and TP3. Powerup.
Connect the globe across the two AC pins of BR2. Does the globe light? What is TP3 measuring?
Then connect it across the + and - pins of BR2. Does the globe light? What is TP3 measuring?

Just trying to see if the voltage supply into and out of the bridge is working under some known load.

#28 12 days ago
Quoted from Quench:

The TP3 voltages you're getting are kind of floaty and the value isn't saying much.

Ugh, sorry I meant TP1 (5V output of the regulator), not TP2.

Okay, so I just went back to test the SDB test points again (J4 on MPU still disconnected) and some strange things just happened:

I plugged the game in and tested TP1 on SDB

TP1 = 5.0vdc so that's good. It has stayed that way each time I've tested, but...

I tested TP5 again:

TP5 = 7.0vdc (also showing this on TP3 of Rectifier too)

I turned OFF the game, then turned it back on

TP5 = 9.6vdc (both SDB and Rectifier)

I turned the game off and on a few times (sometimes right away, sometimes waiting a minute or two), and the voltage on those test points was bouncing in the 7.1-9.7vdc range. I decided to turn off the game and try plugging J4 back into the MPU. Turned it on, and the LED on the board lit briefly, but then slowly faded and went out. I checked TP5 (SDB) and TP3 (rectifier) and they're back down around 2.5vdc again.

Definitely strange.

Sidenote TP3 SDB still zero volts.

#29 12 days ago
Quoted from Quench:

The TP3 voltages you're getting are kind of floaty and the value isn't saying much.
Have you got any 12 volt incandescent globes?

I have some 912 bulbs, 12V but like 12.8W I think. I can dig in my parts, or try those I guess.

#30 12 days ago

quench I just tried something interesting, not sure if this matters but here's what I did:

I turned the game on (J4 still disconnected from MPU, everything else still connected) and I connected the black lead of my meter to the " - " solder point of BR2. I then put my red lead on TP3 of the Rectifier and got 11.47vdc. I checked TP5 of the SDB and got the same reading. But if I connect my black lead to a known ground (like the leg of the resistor on the rectifier, the ground on the SDB, the ground on the MPU, etc.) it shows a lower voltage as indicated in the other tests.

Why would using the negative BR2 connection show all the proper voltages at the test points, but testing from actual "ground" locations show lower voltages?

EDIT #1 - I just checked for continuity from the other Ground points. I have Ground continuity to the " - " connections of BR1 and BR3, but NOT to BR2

EDIT #2 - I decided to jumper the ground side of one of the other bridges to BR2 ground and test TP3 (Rectifier) and TP (SDB). Readings were 16.49vdc... a little high. Not sure if jumpering was a valid idea, but given the lack of ground continuity to BR2, figured worth a shot. Thoughts?

#31 12 days ago

Can we get some gratuitous pics?

#32 12 days ago
Quoted from Daditude:

Can we get some gratuitous pics?

Of the game in general, like the playfield and such?

Here are a couple, before I started taking it apart to clean it, etc. The backglass is in amazing shape, playfield pretty good as well.

LW_bg1 (resized).jpgLW_pf1 (resized).jpg
#33 12 days ago

I used to have a beautiful example of Lost World. I now have a Paragon. Both have gorgeous art packages.

#34 12 days ago

I'm so tempted to try plugging in J4 to the MPU and trying it with my jumper idea above on... but that 16+ vdc is way above the 11.9vdc it should be now. Waiting for someone to chime in before I blow things up ha.

#35 12 days ago
Quoted from MaxAsh:

I'm so tempted to try plugging in J4 to the MPU and trying it with my jumper idea above on... but that 16+ vdc is way above the 11.9vdc it should be now. Waiting for someone to chime in before I blow things up ha.

If you're getting 16V DC with the SDB connected (and the C23 capacitor is reconnected), then this high reading can be normal! Capacitor C23 stores voltage and will bring the DC supply anywhere up to between 14.5 to 17 volts. You can confirm this by disconnecting J3 at the SDB where you will notice TP3 on the rectifier board will drop back to around 12 volts DC output.

Firstly, resolder that "-" pin on BR2. The solder on it looks a bit frosty in your picture above. If resoldering doesn't fix it then jumper ground to it. You are definitely onto something..

#36 11 days ago
Quoted from Quench:

If you're getting 16V DC with the SDB connected (and the C23 capacitor is reconnected), then this high reading can be normal! Capacitor C23 stores voltage and will bring the DC supply anywhere up to between 14.5 to 17 volts. You can confirm this by disconnecting J3 at the SDB where you will notice TP3 on the rectifier board will drop back to around 12 volts DC output.
Firstly, resolder that "-" pin on BR2. The solder on it looks a bit frosty in your picture above. If resoldering doesn't fix it then jumper ground to it. You are definitely onto something..

You're right, thank you! I disconnected J3 from SDB and sure enough the Rectifier TP3 shows 12.5vdc now. I reconnected everything (J3 / J4) and the game booted up again!

I haven't done further testing, but I'll do so and report back. I'll try reflowing that " - " on BR2, and just permanently jumper if that doesn't work like you said.

As a precursor, the next trouble spots I know existed were:

* TP1 (rectifier) showing zero volts for "feature lamps" (it's shown 5.0 before so I bet it's likely something flaky)

* Flippers/Solenoids dead

I'll be back soon with an update. quench thanks so much for sticking with me on this, I appreciate it, we're almost there. More to come...

#37 11 days ago

Update: Okay, so with BR2 properly grounded, the game boots with sound and the displays come on.

* Adding a credit for some reason will add more like 10 credits, but I'll worry about that later.
* I can press start and a game will begin (music plays, ball 1 displays, score goes to zero).
* The ball does not kick out, none of the solenoids will fire, and flippers are dead.
* Manually triggering various switches will score points (and sounds are emitted properly)
* At least one switch somewhere is stuck closed, or intermittent, because sometimes the game will just start scoring non-stop

TP1 on the rectifier is still zero volts
TP5 is showing 44.5 vdc so that solenoid power is present there. Haven't found any blown fuses so far, but the fuse under the playfield near the flippers has a semi-broken clip, so that could be an issue despite seeing continuity there. I'll replace it, but I am not sure that's the problem with the solenoids.

I did jumper from ground to the metal "tabs" on the solenoid board transistors, and the coils did fire for things like the pops and slings.

Thoughts?

#38 11 days ago

When you boot up does the relay on the SDB "click" ?

#39 11 days ago
Quoted from MaxAsh:

TP1 on the rectifier is still zero volts

Are any feature lamps coming on?
What DC voltage are you measuring across the "+" and "-" pins of bridge BR1 on the rectifier board?

Quoted from MaxAsh:

TP5 is showing 44.5 vdc so that solenoid power is present there.

Solenoid power is also used on the sound board as a power source for the amplifier so the 43V supply is working.
What happens when you go to solenoid test mode and the game cycles through activating the solenoids?
As CanadianPinball mentioned, do you hear the flipper enable relay clicking on the SDB when you start a game and during solenoid test mode at solenoid test #11?

BTW before I forget, you have a couple of incorrect fuses on your rectifier board. The only slow blow fuse that should be on there is the one at F6 for mains power. Make sure your mains wall power cable is disconnected before touching that fuse and even the others for your safety..

#40 11 days ago

You said the MPU had corrosion from the battery.

When you switch that out with a new one, did you do anything about all the corrosion in the connectors that plug into the MPU or did you just leave them alone?

#41 11 days ago
Quoted from CanadianPinball:

When you boot up does the relay on the SDB "click" ?

The relay doesn't click at all from what I can tell, not during boot up and not when a game is started, so nothing is happening there from what I see.

Quoted from Quench:

Are any feature lamps coming on?
What DC voltage are you measuring across the "+" and "-" pins of bridge BR1 on the rectifier board?

"Feature lamps" are the inserts? Right now all I have is GI from what I can tell.

zero voltage on the + / - pins of BR1

transformer taps 13 & 14 showing 8.42vac, and so are the AC/AC pins of BR1... so the AC voltage looks like it's getting to the bridge. I know TP1 showed 5.0vdc earlier in my testing, but now nothing.

Solenoid power is also used on the sound board as a power source for the amplifier so the 43V supply is working.
What happens when you go to solenoid test mode and the game cycles through activating the solenoids?
As CanadianPinball mentioned, do you hear the flipper enable relay clicking on the SDB when you start a game and during solenoid test mode at solenoid test #11?

Not 100% sure how to get to solenoid test mode... I used the self test button, and cycled through displays and then other things... nothing ever fired though solenoid-wise that I saw.

I did check for voltage right before that relay on the SDB. I tested at CR20, which is immediately before the relay, and I am getting 44.1vdc , so it looks like the voltage is getting that far.

BTW before I forget, you have a couple of incorrect fuses on your rectifier board. The only slow blow fuse that should be on there is the one at F6 for mains power. Make sure your mains wall power cable is disconnected before touching that fuse and even the others for your safety..

Okay, I'll check out all the fuses and see what's going on there.

Quoted from timab2000:

You said the MPU had corrosion from the battery.
When you switch that out with a new one, did you do anything about all the corrosion in the connectors that plug into the MPU or did you just leave them alone?

timab2000 I have only changed a few pins on the MPU connectors. I was going to re-pin everything, but wanted to sort out the voltage issues back over on the rectifier first, since I still don't technically have all the correct power coming off of there. I guess I could start repinning, since the only incorrect/missing voltage now is the feature lamp.

#42 11 days ago

Follow-up ... Checked for voltage at the fuse under the playfield near the flippers. It's sitting at 44.4vdc on both sides, so no issue there either. So it looks like the power is getting there it needs to so far... just nothing actually working when a game is started, no relay click on, nothing. Only time I can get them to fire is when I manually ground the transistors associated with them.

Should I just start re-pinning all the connectors, or is something else going on I should look at first?

EDIT: Also checked the solenoids themselves, and they are showing 43vdc as well.

#43 11 days ago

You said none 0f the solenoids work? Have you tried ground a tab on the transistor on the the board and see if it fires. The flipper relay is driven by a transistor also. With the game on make a jumper from ground braid and touch the tab and see what happens

#44 11 days ago
Quoted from nitrojcrawf:

You said none 0f the solenoids work? Have you tried ground a tab on the transistor on the the board and see if it fires. The flipper relay is driven by a transistor also. With the game on make a jumper from ground braid and touch the tab and see what happens

Yep, mentioned that above a while back, but there are lots of posts so it's mixed in there. Grounding the transistor tabs fires the coils. I've seen the pops, slings and other fire just fine that way.

#45 11 days ago
Quoted from MaxAsh:

"Feature lamps" are the inserts? Right now all I have is GI from what I can tell.

Yes the lamps under the inserts are called feature lamps.

Quoted from MaxAsh:

"zero voltage on the + / - pins of BR1

transformer taps 13 & 14 showing 8.42vac, and so are the AC/AC pins of BR1... so the AC voltage looks like it's getting to the bridge. I know TP1 showed 5.0vdc earlier in my testing, but now nothing.

Sounds like BR1 might be blown. Did you power the game when the rectifier board was unscrewed from the mounting plate?
Those bridge rectifiers can be difficult to remove. Do a diode test across the BR1 bridge - you will need to unsolder one leg of resistor R2 (25 ohm ceramic resistor) and pull the unsoldered leg out of the board to disconnect it, remove fuse F1 and disconnect J1 and J3 from the rectifier board so you isolate BR1.

Quoted from MaxAsh:

Not 100% sure how to get to solenoid test mode...

Press the little red self test button inside the coin door 3 times. The player displays will count from 1 to 11 and repeat with each number representing a coil/relay. The coil identification numbers are listed in the troubleshooting section of the manual.

Quoted from MaxAsh:

Should I just start re-pinning all the connectors, or is something else going on I should look at first?

First thing, measure the voltage at TP3 on the solenoid driver board. If it's zero volts (should be 5 volts) you have a connector issue on the short brown-white wire between SDB J3 pin 13 to SDB J3 pin 25. An open circuit here will cause no solenoids/coils to activate. Infact this is one of the recommended mods on the SDB to solder a wire on the back of the board from TP1 to TP3 to make sure the logic chips on the SDB have power.

SDB_TP3.jpg

#46 10 days ago
Quoted from Quench:

Yes the lamps under the inserts are called feature lamps.
First thing, measure the voltage at TP3 on the solenoid driver board. If it's zero volts (should be 5 volts) you have a connector issue on the short brown-white wire between SDB J3 pin 13 to SDB J3 pin 25. An open circuit here will cause no solenoids/coils to activate. Infact this is one of the recommended mods on the SDB to solder a wire on the back of the board from TP1 to TP3 to make sure the logic chips on the SDB have power.

Good call! Jumpering TP1 to TP3 on the SDB fixed the dead solenoids!

That being said, I have some bugs there to work out. When I start a game, the ball kicks out, but a pop bumper is rapid-firing, so I'll check the switch then dig into it if that's not the issue. That would explain my non-stop scoring mentioned earlier though, so I'm guessing it's just a stuck/bent pop switch.

I will do some further testing, and also start checking into the BR1 issue. Yes, I did power the game with the rectifier removed from the backing plate. I didn't leave it on long when I did, but is that something that would blow BR1?

#47 10 days ago
Quoted from MaxAsh:

but a pop bumper is rapid-firing, so I'll check the switch then dig into it if that's not the issue.

If the pop bumper has a capacitor across the switch (it should) it might be shorted which is a common failure.

Quoted from MaxAsh:

Yes, I did power the game with the rectifier removed from the backing plate. I didn't leave it on long when I did, but is that something that would blow BR1?

BR1 will die from overheating if not thermally cooled, but actually in your case with it not screwed to the metal backing plate it probably wasn't a cause of failure since the game hasn't been booting so none of the feature lamps were on anyway and there was no current draw through the feature lamp BR1 bridge.

#48 10 days ago
Quoted from Quench:

If the pop bumper has a capacitor across the switch (it should) it might be shorted which is a common failure.

Okay, I'll check that out. If it is failed, I can disconnect the pop for now and work on that. Looking at it currently, so I'll report back in a bit.

BR1 will die from overheating if not thermally cooled, but actually in your case with it not screwed to the metal backing plate it probably wasn't a cause of failure since the game hasn't been booting so none of the feature lamps were on anyway and there was no current draw through the feature lamp BR1 bridge.

Makes sense. Okay, I'll see about doing all those tests you suggest and go from there.

#49 10 days ago

* Okay, I remove one leg of the capacitor on the switch for the machine-gunning pop bumper (right bumper for reference). It stopped firing non-stop.

When I trigger it manually now, it only fires if I hold the switch down a little longer, which I assume makes sense since I think the capacitor was designed to help with it triggering properly? I remember reading that, but could be wrong. I assume if I replace that capacitor, I should be good to go for that issue, right?

EDIT - looks like the schematics refer to the capacitor as .002, so I'm guessing a .0022uf 1000v ceramic disc replacement would work? I see those for cheap over at GPE.

EDIT 2 - glancing at the actual capacitor it looks like it says .05 12V... but I'm wondering, could I just steal the one off the tilt bob if I wanted? It's .05 50V

* Feature lamps definitely all out, which makes sense with no voltage on TP1 of the rectifier. Still haven't take it all apart/out in order to test, I guess that's next.

Good news is that with the pop bumper switch capacitor disconnected, the game seems to be playing aside from a few items. Flippers work, scoring works, most switches good. Right slingshot is scoring, but not firing... probably minor, but I'll look into that next. Displays a little flickery aside from P1, but they're all on. Reflowing solder or repinning at the displays is likely going to help I believe.

#50 10 days ago

It's a good idea to change all those capacitors on the switches under the playfield - the caps Bally used are prone to failure after all these years.
Replace with 0.047uF (47nF), 50V or higher caps. They can be sourced very cheap.

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