(Topic ID: 234894)

6803 no displays

By Michaelxwhite

5 years ago


Topic Heartbeat

Topic Stats

You

Linked Games

Topic Gallery

View topic image gallery

2019-01-29 17_27_41-6803 no displays _ Tech_ Early solid state _ Pinside.com - Internet Explorer (resized).png
15487830285984874584564704073474 (resized).jpg
15487827855097090475390914203717 (resized).jpg
15487246035876725771775079745443 (resized).jpg
15487245815804820675411603891681 (resized).jpg
15487245620317823923719549052486 (resized).jpg
15487245389242705369502286859450 (resized).jpg
15487245256128809955498753946564 (resized).jpg

#1 5 years ago

Good evening pinside community. I have a special forces pinball and when I got the game home I had to do an extensive cleaning (little creature droppings and nest removal), as it was stored in a barn. Any rate, I cleaned it up and checked all the boards and connections over really well and started it up. It played well, but all of a sudden there was a distinct crackle pop sound that came from the back box and the right side display was out, few seconds later another distinct crackle and pop and the main display is out. Now, I have all 9 flashes on the cpu and it will do the attract mode to show you how the rules work when bottom right button is pushed. All the sound works great, as well as speech.

Also of note in pictures, I replaced with a new power supply and a new battery mod on the Mpu.

What should I be looking for?

Thanks in advance for any help and kind regards.

15487245256128809955498753946564 (resized).jpg15487245256128809955498753946564 (resized).jpg15487245815804820675411603891681 (resized).jpg15487245815804820675411603891681 (resized).jpg15487245389242705369502286859450 (resized).jpg15487245389242705369502286859450 (resized).jpg15487245620317823923719549052486 (resized).jpg15487245620317823923719549052486 (resized).jpg15487246035876725771775079745443 (resized).jpg15487246035876725771775079745443 (resized).jpg
#3 5 years ago

Have you checked the high voltage with a meter to see what it's reading? If the new power supply follows the original with test point identification, it'd be TP2 you'd want to check on DC voltage. Exercise caution of course, since it's high voltage. And on that note, unplug the displays to avoid any additional damage to them while you're testing the power supply.



Power Supply Test Points.
With the game's power on check the power supply test points:

TP10 = ground (bottom left corner)
TP1 = +5 volts DC (top right corner)
TP2 = 170-190 volts DC (high voltage out, middle of board, adjustable via trim pot VR1)
TP3 = 230 volts DC (high voltage in, middle of board)
TP4 = 43 volts DC (solenoid voltage, top left).
TP5 = 14 volts DC (main logic power before regulation, middle of board)
TP6 & TP7 = 11 volts AC (lamp matrix)
TP8 & TP9 = 6.3 volts AC (General illumination)

Source: http://www.pinrepair.com/6803/#displays


It's not sounding too good with a crackle pop and dead displays AFTER they were working. Did they go super nova (light up almost pink) and then disappear? I don't see really dark segments, so they *could* be okay.. but it really seems to indicate there was a short somewhere or higher voltage into a component. You could pull one or both displays to see if you can find out what went crackle/pop. Usually if you hear it, you can SEE it too.. burnt mark on the board, cracked transistor or an IC that has a hole burnt through the middle.

#4 5 years ago

On my Motordome i had to switch out thaty little chip on the display itself ("chip 1" i think its named) to get mine back up and running, check if that popped.

#5 5 years ago

I'll check the display chip 1, and voltages.

#6 5 years ago

Here are the backs of the boards, nothing burnt or blown.

15487827855097090475390914203717 (resized).jpg15487827855097090475390914203717 (resized).jpg15487830285984874584564704073474 (resized).jpg15487830285984874584564704073474 (resized).jpg
#7 5 years ago
Quoted from Michaelxwhite:

Here are the backs of the boards, nothing burnt or blown.

Hey that's always a plus! Interesting, wonder what the crackling was. Any fuses blown on the power supply board or do those all look fine? With the game off you may need to check with continuity test across the fuse with a meter. Sometimes it's hard to tell depending on how they blow, especially the HV fuses which are often thin wire.

Of course if you've checked voltages at the test points you'll probably know if a fuse has blown as well.

#8 5 years ago

Power supply fuses are good; perhaps, it's the cpu? Not resetting? When I push the red button on the cpu nothing happens, and there is the right flipper that gets power as soon as the game is turned on. Not sure why the flipper constantly has power except that is the last state the game was in when I turned it off and replaced the battery on the cpu with the data retention chip. I looked over the cpu and no burn on any transistors or resistors, no trace corrosion from previous battery. At this point I'm thinking it is a chip. Any advice is greatly appreciated.

#9 5 years ago

Could one of the capacitors on the cpu popped and crackled? Sounded like Rice Krispies kind of when whatever it was went; it was just the crackle and pop though.

#10 5 years ago
Quoted from Michaelxwhite:

Could one of the capacitors on the cpu popped and crackled? Sounded like Rice Krispies kind of when whatever it was went; it was just the crackle and pop though.

Sometimes crackling can be a component or connector heating up but not actually popping.

Did you try swapping the original RAM back in? Easy enough to do just to eliminate that from the equation. On that note, is the NVRAM seated fully? Sometimes I've had people plug mine in and not insert it fully into the socket. You may have to remove the MPU from the machine and set it on a flat surface so it's not flexing the board too much. Just mentioning this since a bad connection there could cause some weird things to happen, since it's the memory for the machine.

#11 5 years ago

Nvram good to go, it's not that, plugged old back in same. This all happened before new ram was installed.

#12 5 years ago

I have not seen where you have tested the voltages yet since acebathound mentioned it on post #3.

Is this connector seated?
2019-01-29 17_27_41-6803 no displays _ Tech_ Early solid state _ Pinside.com - Internet Explorer (resized).png2019-01-29 17_27_41-6803 no displays _ Tech_ Early solid state _ Pinside.com - Internet Explorer (resized).png

#13 5 years ago
Quoted from Michaelxwhite:

Power supply fuses are good; perhaps, it's the cpu? Not resetting? When I push the red button on the cpu nothing happens, and there is the right flipper that gets power as soon as the game is turned on. Not sure why the flipper constantly has power except that is the last state the game was in when I turned it off and replaced the battery on the cpu with the data retention chip. I looked over the cpu and no burn on any transistors or resistors, no trace corrosion from previous battery. At this point I'm thinking it is a chip. Any advice is greatly appreciated.

Is the game booting into attract mode otherwise? From your initial posts it sounded like the game was working fine for a bit and then the displays went.. but then you mention the locked on flipper happening. So stepping back a bit, was the game working with the old power supply, displays and all? And did the displays then go out with the old supply, followed by purchase of the new power supply + nvram. Or did this all occur after installing the new power supply? Just trying to understand sequence of events.

Usually the best thing to do with these games, especially if in unknown condition, is to isolate things and work your way from the transformer/power supply forward. So you'd start with the transformer input going to the power supply, no other connections (or minimal to get some proper voltages there). Check voltages at the power supply. Then plug in the next thing. At the MPU you could leave some of the lamp/solenoid harnesses unplugged, just have the harness supplying voltages/grounds going to the MPU.. that prevents solenoids or lamps from locking on if there's MPU issues -- or blowing transistors if there's a coil problem. Doing it this way, you aren't throwing a new power supply into an unknown game and hoping for the best. It does take a while to step through things in this way, but then you know the last step you took if you do have an issue as you continue adding new boards or harnesses into the mix.

Definitely don't want to test voltages while leaving a flipper locked on..

#14 5 years ago

First you need a working game/MPU that's not locking on a flipper coil, is getting 9 flashes, boots into attract mode and plays a game blindly. The suggestion of checking display voltages at TP2 on the power supply was assuming the rest of the game was working and should still be done at some point.. but that flipper locking on immediately is no good.

Sorry I think I'm a bit confused where the game is at or the sequence of events.

Did it go..

1. Game works with old power supply.
2. Displays die.
3. New power supply ordered & installed as possible display fix. NVRAM also installed.
4. Game now locks on flipper coil and may be doing other odd stuff.

Or did the display issues occur after the new power supply was installed?

#15 5 years ago

Did you double check the j2 connector?

#16 5 years ago
Quoted from PinballManiac40:

I have not seen where you have tested the voltages yet since acebathound mentioned it on post #3.
Is this connector seated?
[quoted image]

Connection is good, seated well, checking voltages today.

#17 5 years ago
Quoted from drsfmd:

Did you double check the j2 connector?

Connection to j2 on the cpu is also good.

#18 5 years ago

Is the game booting into attract mode otherwise? From your initial posts it sounded like the game was working fine for a bit and then the displays went.. but then you mention the locked on flipper happening. So stepping back a bit, was the game working with the old power supply, displays and all? And did the displays then go out with the old supply, followed by purchase of the new power supply + nvram. Or did this all occur after installing the new power supply? Just trying to understand sequence of events.

Starting from the beginning, game worked fine except for a flipper that wouldn't return. Flipper also melted the new spring (short in flipper coil fixed, new one installed) new spring works fine. Then the fun starting happening....

1.) rice krispie crackle pop, display 1 out, few minutes later,

2.) Rice Krispies crackle pop display 2 out,

3.) Game started acting funny (right flipper could be used in attract mode, no flippers or coils are locked on) then,

4.) I decided to look at Mpu for battery which believe it or not by some miracle was fine, but replaced with nvram, game was in same condition as before I installed nvram. So I decided to purchase a new power supply because there are no power supply kits for 6803 and I just don't have to time to find all the different could from multiple different websites;

5.) New power supply and game is in the same condition. No displays, right flipper active during attract, playfield lights, sound board... Everything working in attract, but still no displays and unable to reconfigure to see state of game and no burnt/blown electricals or connectors anywhere on any boards.

Sorry for the timeline confusion.

#19 5 years ago
Quoted from acebathound:

First you need a working game/MPU that's not locking on a flipper coil, is getting 9 flashes, boots into attract mode and plays a game blindly. The suggestion of checking display voltages at TP2 on the power supply was assuming the rest of the game was working and should still be done at some point.. but that flipper locking on immediately is no good.
Sorry I think I'm a bit confused where the game is at or the sequence of events.
Did it go..
1. Game works with old power supply.
2. Displays die.
3. New power supply ordered & installed as possible display fix. NVRAM also installed.
4. Game now locks on flipper coil and may be doing other odd stuff.
Or did the display issues occur after the new power supply was installed?

It is getting 9 flashes. Boots into attract...can't reconfigure without displays... Right flipper is not locked on just active during attract.

#20 5 years ago
Quoted from acebathound:

Is the game booting into attract mode otherwise? From your initial posts it sounded like the game was working fine for a bit and then the displays went.. but then you mention the locked on flipper happening. So stepping back a bit, was the game working with the old power supply, displays and all? And did the displays then go out with the old supply, followed by purchase of the new power supply + nvram. Or did this all occur after installing the new power supply? Just trying to understand sequence of events.
Usually the best thing to do with these games, especially if in unknown condition, is to isolate things and work your way from the transformer/power supply forward. So you'd start with the transformer input going to the power supply, no other connections (or minimal to get some proper voltages there). Check voltages at the power supply. Then plug in the next thing. At the MPU you could leave some of the lamp/solenoid harnesses unplugged, just have the harness supplying voltages/grounds going to the MPU.. that prevents solenoids or lamps from locking on if there's MPU issues -- or blowing transistors if there's a coil problem. Doing it this way, you aren't throwing a new power supply into an unknown game and hoping for the best. It does take a while to step through things in this way, but then you know the last step you took if you do have an issue as you continue adding new boards or harnesses into the mix.
Definitely don't want to test voltages while leaving a flipper locked on..

Flipper is not locked on, it's current state is the same as before I changed the nvram, new power supply. Two separate crackle pop situations resulting I. Two dead, but still good displays. Right flipper not locked on, but still useable during attract. Sound and speech all work during attract, just no displays. Flipper was not working correctly, turned game off and sanded contacts flipper started working, left flipper return spring broke, installed new one and it melted it, replaced coil all good, played a couple of games and that's when the displays went and right flipper can be used during attract. Game won't reset on button on cpu. Just stays in same state.

#21 5 years ago

Here is a link to a video I put up on youtube:

#22 5 years ago
Quoted from Michaelxwhite:

Here is a link to a video I put up on youtube:

That's a really good video, nice job explaining everything you've got going on and what steps you took so far!

I didn't realize you had an orange glow at the displays. I'm gonna take a quick look at the schematics to see if anything jumps out.

#23 5 years ago
Quoted from acebathound:

That's a really good video, nice job explaining everything you've got going on and what steps you took so far!
I didn't realize you had an orange glow at the displays. I'm gonna take a quick look at the schematics to see if anything jumps out.

Thank you so much!

#24 5 years ago

Looks like segment data for the displays comes out of the U7 6821 PIA on the MPU. There's also momentary solenoid, continuous solenoid, solenoid bank select. If you had a logic probe you could try probing pins 2-9 on U7. I'd imagine that chip to see if there's activity while the game's in attract mode. Those U7 pins seem to feed the data to the 74HC373 chip that's on each display.

The flipper thing is odd.. which also has me wondering if the U7 PIA is to blame. It would kind of make sense if that chip was dead, why the displays weren't lighting and why you can activate a flipper since it looks like PB16 (pin16 of U7 on the schematic) is involved with the flipper enable relay.

If you have spare good PIA chips, throwing one in there might not hurt. I'm not sure what swapping the U7 and U8 PIA might do, so don't know if I'd advise that.. on the older Bally games you could swap PIAs and if it created different issues you had a pretty good idea what the cause was. You could try it, but results may vary

Just FYI there's a handy little tester at http://www.neoloch.com called the "Inquisitor".. that has both RAM testing blades and also a PIA testing blade. If you're fixing up a lot of older pinball machines (90s on back), most of them use those PIA chips and having a way to test them easily is nice.

I keep going back to the thought of U7 being involved here at this point... there's a chance it's +5v not making it to the display, but with a glow at both of those displays & the same issue taking them out, it seems like it's further up the chain as I'm sure you're suspecting as well. So if it's display data related, I'd say it's less likely for it to be the BCD data involved in digit enable.. and more likely it's the PIA feeding the segments data to the displays. Plus that weird flipper thing happening.. and for that PIA to be involved with flipper enable..

#25 5 years ago

So....you're saying replace u7 on the Mpu? What could of caused it to go? Unregulated current from old power supply? Have you heard of a chip crackle and pop before with no visible damage?

#26 5 years ago
Quoted from Michaelxwhite:

So....you're saying replace u7 on the Mpu? What could of caused it to go? Unregulated current from old power supply? Have you heard of a chip crackle and pop before with no visible damage?

Just a guess based on symptoms (no displays, flipper issue) and U7 being involved there.

That said, looking at the manual, the 6th flash happens after the software tests U7. Not sure how extensive the test is. It was just a thought if you had a PIA to throw in there, since U7 is in a socket it'd be an easy enough test.


As far as testing the displays further, well, there's test points on the back for 180VDC and 80VDC.. if you had alligator clips you could measure voltages there, but definitely need to be careful hooking things up on the back of those and don't want to handle the displays while you're testing them. High voltage sucks.

There's no +5v test point on the back of the displays, but that you could test with the POWER OFF to the game. You'd have to find something that 5v is feeding on the display (ie. one of the logic chips on the display) and then use continuity test on your meter to a 5v test point on the MPU to see if you get a beep.

At that point you'd rule out any voltages not getting to the displays and be left with display signals. Now if just a single segment didn't reach the display, or just a single BCD line.. you'd probably still get something out of the display. But if it's a latch/strobe or all the segment data isn't hitting the display.. then it wouldn't light up. With both displays affected, and no blown components on the back of the display, and an orange glow out of them.. and an MPU that looks pretty decent, I was just thinking U7 looked like it was involved.

This is then where a logic probe would help.. since you could probe a few things back at the MPU to see some of the low voltage signals are being generated for the display (digit enables, segment data, latch, etc).

If you haven't already, try reseating the display connector on the MPU.

I hate to throw too many things out there, but I also came across this post talking about D23/D19 going bad..
https://pinside.com/pinball/forum/topic/need-a-bally-6803-exper

D23/D19 are diodes in the flipper enable circuit. There's part of the schematic shown in one of the posts.. maybe check those diodes? They should be near the relay at the top right of the MPU I would think. With the flipper short having occurred, maybe back EMF did affect something in that flipper enable circuit and got back to U7.

#27 5 years ago
Quoted from acebathound:

Just a guess based on symptoms (no displays, flipper issue) and U7 being involved there.
That said, looking at the manual, the 6th flash happens after the software tests U7. Not sure how extensive the test is. It was just a thought if you had a PIA to throw in there, since U7 is in a socket it'd be an easy enough test.

As far as testing the displays further, well, there's test points on the back for 180VDC and 80VDC.. if you had alligator clips you could measure voltages there, but definitely need to be careful hooking things up on the back of those and don't want to handle the displays while you're testing them. High voltage sucks.
There's no +5v test point on the back of the displays, but that you could test with the POWER OFF to the game. You'd have to find something that 5v is feeding on the display (ie. one of the logic chips on the display) and then use continuity test on your meter to a 5v test point on the MPU to see if you get a beep.
At that point you'd rule out any voltages not getting to the displays and be left with display signals. Now if just a single segment didn't reach the display, or just a single BCD line.. you'd probably still get something out of the display. But if it's a latch/strobe or all the segment data isn't hitting the display.. then it wouldn't light up. With both displays affected, and no blown components on the back of the display, and an orange glow out of them.. and an MPU that looks pretty decent, I was just thinking U7 looked like it was involved.
This is then where a logic probe would help.. since you could probe a few things back at the MPU to see some of the low voltage signals are being generated for the display (digit enables, segment data, latch, etc).
If you haven't already, try reseating the display connector on the MPU.
I hate to throw too many things out there, but I also came across this post talking about D23/D19 going bad..
https://pinside.com/pinball/forum/topic/need-a-bally-6803-exper
D23/D19 are diodes in the flipper enable circuit. There's part of the schematic shown in one of the posts.. maybe check those diodes? They should be near the relay at the top right of the MPU I would think. With the flipper short having occurred, maybe back EMF did affect something in that flipper enable circuit and got back to U7.

First and foremost, WoW....very thoughtful and thorough response. Thank you very much! I don't possess a decent logic probe, just a cheap one off of the bay. Doesn't seem to help much. But, I did just order the pia you suggested. I'd hate to put u8 in u7 and possibly mess that chip up. It's true, all the fun started with the flipper short that melted the return spring. I'll work on Everything you suggested tomorrow, hope my dvom will suffice for most of it.

#28 5 years ago

"acebathound"- I just finished reading your link provided above and see that a bad diode could in fact be the culprit that allowed this mess to happen; furthermore, allowing the flipper short to cause havoc up the Mpu board. Makes perfect sense considering that's when everything went South.

#29 5 years ago

Unfortunately when I swapped u8 and u7 nothing changed. I'll have to read through the manual.

#30 5 years ago
Quoted from Michaelxwhite:

Unfortunately when I swapped u8 and u7 nothing changed. I'll have to read through the manual.

There could still be something to that whole back EMF think & diodes in the flipper enable circuit. If your meter has a diode test (usually only the more expensive ones do) then you could check those with the machine off. On diode test, you should get a reading one way (maybe .6v or higher) and no reading the other way.. usually meters beep continuously if it's shorted. I'm not sure how failed diodes there would affect an otherwise working PIA.

Might be time to break out the logic probe, or get a better logic probe if you don't think yours is up to snuff. Then you can check the lower voltage signals being generated by U7 for the segments is pulsing high/low (PIA pins as noted in an earlier post). You could also check the BCD data for the digit enables is pulsing high/low.

Unfortunately seems you're at a point where you've got to go "deeper" into the technical side of things to see where a signal or voltage is being dropped. That is, if you're getting 180v and 80v at the display test points. If you aren't getting the correct voltage at those test points, that's a problem.

#31 5 years ago
Quoted from acebathound:

There could still be something to that whole back EMF think & diodes in the flipper enable circuit. If your meter has a diode test (usually only the more expensive ones do) then you could check those with the machine off. On diode test, you should get a reading one way (maybe .6v or higher) and no reading the other way.. usually meters beep continuously if it's shorted. I'm not sure how failed diodes there would affect an otherwise working PIA.
Might be time to break out the logic probe, or get a better logic probe if you don't think yours is up to snuff. Then you can check the lower voltage signals being generated by U7 for the segments is pulsing high/low (PIA pins as noted in an earlier post). You could also check the BCD data for the digit enables is pulsing high/low.
Unfortunately seems you're at a point where you've got to go "deeper" into the technical side of things to see where a signal or voltage is being dropped. That is, if you're getting 180v and 80v at the display test points. If you aren't getting the correct voltage at those test points, that's a problem.

They're lighting at the base so they're getting voltage. Put a new cpu in and the flipper issue went away, but no displays. At this point, it's got to be the transformer, which is a bit shocking. Must of been what the crackle and pop was, but it makes little sense that is the issue because the displays went out at different times. If the transformer went, wouldn't both displays go out at the same time?

#32 5 years ago

Try a new power driver board, It controls the high voltage.

#33 5 years ago

Sounds like a short in the HV to the displays.

#34 5 years ago

crackle and pop is prob not the mpu.

#35 5 years ago

Try wiggling the wires on the J2 connector at the MPU. I had to repin this connector on a Lady Luck because of the flaky IDC connector.

#36 5 years ago
Quoted from jj44114:

Try a new power driver board, It controls the high voltage.

Bought a new one and no change.

#37 5 years ago
Quoted from PinballManiac40:

Try wiggling the wires on the J2 connector at the MPU. I had to repin this connector on a Lady Luck because of the flaky IDC connector.

Done this with no success.

#38 5 years ago

Oh boy, I think the problem is a playfield ghost on The three bank in line drop target fixture. If I start the game with one of those three drops down cpu only gives three flashes, when I turn game off and manually reset bank and restart I get 9 flashes again.

#39 5 years ago

Manual is coming In the mail. I will report back as I get serious with this machine.

2 weeks later
#40 5 years ago
Quoted from Luzur:

On my Motordome i had to switch out thaty little chip on the display itself ("chip 1" i think its named) to get mine back up and running, check if that popped.

You were correct good sir, both u1 chips on the display boards were the culprit. Goes into attract, all sounds work, displays good, bad power supply friend two legs on each display boards u1, had to use a loop to see where they were bad. Now just need to work on getting left flipper working and ball count switches registering. Thanks to everyone on this post!

#41 5 years ago
Quoted from Michaelxwhite:

Now just need to work on getting left flipper working and ball count switches registering.

Congrats on your progress! Just wanted to throw in my 2 cents regarding the switch problem--you'll likely want to replace all the 0.047 caps that are soldered to certain switches under the playfield. The schematics will show which switches use one of those caps. They are typically old original ones, and many switch problems on these games wind up being an issue with one or more of those old ceramic caps you'll find on some of the switches.

Keep up the good work!

#42 5 years ago
Quoted from frunch:

Congrats on your progress! Just wanted to throw in my 2 cents regarding the switch problem--you'll likely want to replace all the 0.047 caps that are soldered to certain switches under the playfield. The schematics will show which switches use one of those caps. They are typically old original ones, and many switch problems on these games wind up being an issue with one or more of those old ceramic caps you'll find on some of the switches.
Keep up the good work!

It seems I have only one firing coil = right flipper. During solenoid test not a single coil fires. Also, the fuse on underside playfield, 1amp slow blow, blows instantly upon powering up the game. Any suggestions?

#43 5 years ago

Also, looking at switch matrix in the manual doesn't help much as the flippers are not included and that is where I'm assuming the issue is as right flipper is working in attract mode and game won't start and no other solenoids work at all including in test mode.

Promoted items from the Pinside Marketplace
$ 22.50
Magazines/books
Pinball Magazine
Magazines/books
$ 5.95
Playfield - Protection
The Pinball Scientist
Protection
$ 18.95
Eproms
Pinballrom
Eproms
$ 36.95
Eproms
Pinballrom
Eproms
$ 44.99
Cabinet - Shooter Rods
Pinball Shark
Shooter rods
1,550
Machine - For Sale
Blaine, TN
From: $ 1.25
Playfield - Other
Rocket City Pinball
Other

Reply

Wanna join the discussion? Please sign in to reply to this topic.

Hey there! Welcome to Pinside!

Donate to Pinside

Great to see you're enjoying Pinside! Did you know Pinside is able to run without any 3rd-party banners or ads, thanks to the support from our visitors? Please consider a donation to Pinside and get anext to your username to show for it! Or better yet, subscribe to Pinside+!


This page was printed from https://pinside.com/pinball/forum/topic/6803-no-displays?hl=michaelxwhite and we tried optimising it for printing. Some page elements may have been deliberately hidden.

Scan the QR code on the left to jump to the URL this document was printed from.