(Topic ID: 105354)

Meteor Drop Bank Won't Reset


By CUJO

5 years ago



Topic Stats

  • 75 posts
  • 9 Pinsiders participating
  • Latest reply 3 years ago by Quench
  • Topic is favorited by 1 Pinsider

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Linked Games

  • Meteor Stern Electronics, 1979

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19_LOGIC_PROBE_EISTAR.pdf (PDF preview)
19_LOGIC_PROBE_EISTAR.pdf (PDF preview)

There are 75 posts in this topic. You are on page 2 of 2.
#51 3 years ago

I had a similar issue with my 3 bank where one stopped working. I attributed it to acid damage on my MPU. I bought a new MPU and problem went away but my MPU was pretty bad.

#52 3 years ago
Quoted from CUJO:

I tried pressing on U1 and U3 while running solenoid test and couldn't get Drop Bank 3 to reset. I had already replaced Q13 before.

Yeah it's not a scientific test - your mileage may vary

Quoted from CUJO:

Gonna replace U1..It would be U1 that would be the pre-tranny array that includes Q13, correct?

That I can't tell you. I think there's U1 U2 U3 that all are pre drive arrays? No clue anymore what drives what though

#53 3 years ago
Quoted from Purpledrilmonkey:

Yeah it's not a scientific test - your mileage may vary

That I can't tell you. I think there's U1 U2 U3 that all are pre drive arrays? No clue anymore what drives what though

Looking at the schematic, I think culprit would be IC CA3081 (U3) (feeds Q13) which is the transistor responsible for BANK 3 reset.

I am pretty bad at understanding schematics so if someone could chime in before I cut out the wrong CA3081, that'd be great!

#54 3 years ago
Quoted from SealClubber:

I had a similar issue with my 3 bank where one stopped working. I attributed it to acid damage on my MPU. I bought a new MPU and problem went away but my MPU was pretty bad.

My MPU board looks very healthy so probably not that..Thanks.

#55 3 years ago

On a Bally U3 drives Q13. The Stern is a clone of the Bally, so it *should* be the same.

Before you cut out that chip use your logic probe or meter to try to isolate the failure to that chip.

Pull the playfield glass.
Reset the target bank.
Start up a game.
Thump the targets one at a time. After each one goes down, verify sounds and score are generated.
Tap a jumper from ground to Q13's tab to reset target bank.
Probe U3 pin 12. Keep it there and drop all the targets.
The signal at 12 should toggle very quickly.
The meter will respond by displaying the value change, then return to the reading before the targets were dropped.
A logic probe will respond by blinking its LEDs.

Probably a better description over at pinwiki.com

Try to nail down the failure before destroying a getting-harder-to-find component.

IMO

#56 3 years ago

Thanks Cody. Will try this first and let you know what I find out.

#57 3 years ago
Quoted from cody_chunn:

On a Bally U3 drives Q13. The Stern is a clone of the Bally, so it *should* be the same.
Before you cut out that chip use your logic probe or meter to try to isolate the failure to that chip.
Pull the playfield glass.
Reset the target bank.
Start up a game.
Thump the targets one at a time. After each one goes down, verify sounds and score are generated.
Tap a jumper from ground to Q13's tab to reset target bank.
Probe U3 pin 12. Keep it there and drop all the targets.
The signal at 12 should toggle very quickly.
The meter will respond by displaying the value change, then return to the reading before the targets were dropped.
A logic probe will respond by blinking its LEDs.
Probably a better description over at pinwiki.com
Try to nail down the failure before destroying a getting-harder-to-find component.
IMO

I have a new logic probe but first time using it.
It is a Chinese special.

LP-1
EISTAR

So the available settings are: CMOS/TTL.
MEM/PULSE

and the red and black alligator clips go...I assume black will be any ground on the board but where should I put the red alligator clip?

Thanks! Ready to test..

19_LOGIC_PROBE_EISTAR.pdf

#58 3 years ago

Found this helpful write up with gOOGLE sEARCH.

Guess I'll read and educate myself! Almost looks like my DRIVER/POWER BOARD too!

http://homepinballrepair.com/digitalprobe.html

#59 3 years ago

Update: Resolved!
Before I put the driver board back in, Q13 looked sketchy.. The top was "bronze" looking, like it had gotten hot.

I snipped it out, replaced with new TIP102 and put back in pin. All working!

I tested the snipped out transistor and it tests ok out of the game.
So not sure if it failed internally anyway or if it just had a broken connection on the board?

Either way, working, thanks to all that helped and we'll see how long this goes.

#60 3 years ago

And you didn't kill what turned out to be a good component! Good job.

Enjoy it, it's a great game.

#61 3 years ago
Quoted from cody_chunn:

And you didn't kill what turned out to be a good component! Good job.
Enjoy it, it's a great game.

Yes sir. Saved a CA3801 from the snips! A local pin friend ordered one for me from Marco and I have it here now just in case, in the future, if needed!

Thanks Cody for posting.

1 week later
#62 3 years ago

Update: Well, tonight Bank 3 decided to quit resetting again...
Cody, what in the world keeps blowing out the Q13 TIP102 after 20-25 games?
This is exactly what happened before ..now twice!
Maybe I should replace the CA3801 or do you think something else may be to blame here?

#63 3 years ago

You're getting overvoltage/overcurrent on the transistor that's causing it to blow.

You might have a flaky connection on the diode that sits across the drop target reset coil lugs. Suggest you just replace the diode on the actual coil, they're only a few cents. If the diode's flaky, it'll cause the transistor to blow due to excessive back EMF voltage.
When you take the diode off the coil, measure the coil resistance. Compare the resistance to one of the other drop target reset coils. If the coil resistance is lower then you might have a partially shorted coil causing overcurrent.

I'd say it's unlikely to be the CA3801.

#64 3 years ago
Quoted from Quench:

You're getting overvoltage/overcurrent on the transistor that's causing it to blow.
You might have a flaky connection on the diode that sits across the drop target reset coil lugs. Suggest you just replace the diode on the actual coil, they're only a few cents. If the diode's flaky, it'll cause the transistor to blow due to excessive back EMF voltage.
When you take the diode off the coil, measure the coil resistance. Compare the resistance to one of the other drop target reset coils. If the coil resistance is lower then you might have a partially shorted coil causing overcurrent.
I'd say it's unlikely to be the CA3801.

Thanks for the response Quench. I'll try what you suggest this week and report my findings.

#65 3 years ago
Quoted from CUJO:

Thanks for the response Quench. I'll try what you suggest this week and report my findings.

Do you feel I should also replace the diode on the driver board while I'm replacing TIP102 Q13 again?

#66 3 years ago

Sorry, I just realised you have a long history of issues with this coil not firing for various reasons.
At this stage yeah, while replacing Q13, I would probably also replace the CR13 diode on the driver board.
You can probably replace the other support components C5, R21 and R22 if you want. If you don't have spares handy and can't wait, swap them with the ones used on the Q5 output transistor since there's no coils connected to that transistor.

How did you go with checking out/replacing the diode on the coil itself, and did you manage to measure the coil resistance and compare it to another drop target reset coil?

#67 3 years ago
Quoted from Quench:

Sorry, I just realised you have a long history of issues with this coil not firing for various reasons.
At this stage yeah, while replacing Q13, I would probably also replace the CR13 diode on the driver board.
You can probably replace the other support components C5, R21 and R22 if you want. If you don't have spares handy and can't wait, swap them with the ones used on the Q5 output transistor since there's no coils connected to that transistor.
How did you go with checking out/replacing the diode on the coil itself, and did you manage to measure the coil resistance and compare it to another drop target reset coil?

Quench:

Haven't done that coil /diode/compare resistance test yet.
Was going to wait to hear what your suggestion was on the driver board diode first.
Probably won't get to it until this weekend.
Thanks!

#68 3 years ago

Is that CR13 a 1N4004 diode?

#69 3 years ago

Yep, CR13 is a 1N4004 diode.

#70 3 years ago

Update: I snipped out CR13 and Q13 and replaced both with new.
Re-install board, power on, start a game..Bank 3 again resetting properly.
I did not check the BANK 3 coil or diode but will if this problem surfaces again.

I checked the old diode and it was very hard to get a steady reading on it in the flow direction.
I get a 1.00 one way and occasionally it would blip to .567 but only for a fraction of a second.
The new diode had a steady ready on both ends when tested flipped. 1.00 and .567 +- .100..

#71 3 years ago

That's a good sign you've found a faulty component.
I highly recommend you replace the diode on the coil too. It's another 1N4004 or use a 1N4007 which are generally cheaper and easier to get these days (1N4007 supports higher reverse voltage).

#72 3 years ago
Quoted from Quench:

That's a good sign you've found a faulty component.
I highly recommend you replace the diode on the coil too. It's another 1N4004 or use a 1N4007 which are generally cheaper and easier to get these days (1N4007 supports higher reverse voltage).

I decided to do just as you say. I have the playfield up and will snip out and replace that diode later today.
No sense watching the TIP102 burn up again in 1-2 months, even if this diode isn't the cause.
Thanks!

#73 3 years ago

Good luck with it!
Hope it behaves and you enjoy this cool game

#74 3 years ago

Hi Quench!

Well, I snipped out the 1N4004 off the Bank 3 coil and installed a new one today.
I tested the diode I snipped out with the DIODE test on my DVM.
I got 1.00 one direction and .56 the other way so I guess that was good.

I did notice that the diode across the coil lugs on TARGET BANK 1 was broken!
I noticed what appeared to be solder residue on the banded side and when I went to investigate, it was a broken connection.
Someone before me tried to "touch solder" the wire together on the banded side break to complete the circuit.
Anyhow, it was broken so I snipped out this diode as well and replaced w/ new 1N4004.

Game still works with BANK 3 resetting but I'm wondering now if the BANK 1 diode break had anything to do with
the issue I was having with Bank 3.

#75 3 years ago
Quoted from CUJO:

I did notice that the diode across the coil lugs on TARGET BANK 1 was broken!

Good eye! you've just saved another transistor on the SDB from imminent failure.

Quoted from CUJO:

Game still works with BANK 3 resetting but I'm wondering now if the BANK 1 diode break had anything to do with the issue I was having with Bank 3.

Hmm, they're on separate circuits so it's unlikely.

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