Squawk &amp; Talk trouble shooting

http://www.pinwiki.com/wiki/index.php?title=Leon_Borre%27s_Repair_Articles

My medusa came without a squawk & talk board but I was able to find a prodject board thanks to a very helpful pinsider. I have recapped the board and have been testing it in my fathom but am having some issues with it. The indicator led lights up 4 times like it should on startup. Upon starting a game the sound will play until a switch is hit and then everything starts to get screwy. The background noise will stop and the wrong sounds and call outs will start and play contiously or stop half way through. I know that the rom chips at U4 & U5 (this is in fathom not medusa) are good and i believe i have all the jumpers set correctly. I'm not sure which of the other chips I should try swapping/replacing to correct the problem. Any thoughts or advice is much appreciated.

#2 6 years ago

MVC

Pinthetic

Pinside member

Lodi, CA

13y 49,600 265 1

Go here:

#3 6 years ago

AMS

barakandl

So do you have the proper sound ROMs for Medusa? I would expect odd operation if you have fathom sound roms in a medusa game.

#4 6 years ago

MIL

Thrillhouse

Thank you both. barakandl I should have been more clear, I have the fathom roms in the s&t board and am testing on fathom.

#5 6 years ago

AMS

barakandl

Maybe an input signal problem. Do you have a logic probe? put the game in sound test and check on each side of the 4049 chip. A 4049 chip is a signal inverting chip, so the input is opposite the from the output. Connector pin 12 on the far left may not be used in Fathom.

The EE jumpers route if the inputs go the PIA or the sound gen when it is used, which i don't think it is used in fathom (or medusa).

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#6 6 years ago

AMR

BigAl56

Pinside+ Frequent

Palatine, IL

7y 64,800 1,658

Is the board jumpered for Fathom? I thought fathom had a different sound chip set and had a different jumper pattern?

#7 6 years ago

AMS

barakandl

Quoted from BigAl56:
Is the board jumpered for Fathom? I thought fathom had a different sound chip set and had a different jumper pattern?

i think they should be the same by my notes. No sound gen and same ROM size and mapping

#8 6 years ago

MIL

Thrillhouse

Thank you again @barakandl, I'll need to get a logic probe. I'll report back in a few days. The prodject boards jumpers have been set to match the fathoms existing working board. A local friend has a working medusa and I have compared the boards and can confirm both fathom & medusa do not use U12 and need the jumpers installed at EE. I am testing the board in fathom because I am more familiar with the callouts and sounds and the game plays 100%. The medusa is a scratch build and not working 100% yet, I'm also not really familiar with the sounds/callouts for it.

#9 6 years ago

AMS

barakandl

OP
Quoted from Thrillhouse:
Thank you again barakandl, I'll need to get a logic probe. I'll report back in a few days. The prodject boards jumpers have been set to match the fathoms existing working board. A local friend has a working medusa and I have compared the boards and can confirm both fathom & medusa do not use U12 and need the jumpers installed at EE. I am testing the board in fathom because I am more familiar with the callouts and sounds and the game plays 100%. The medusa is a scratch build and not working 100% yet, I'm also not really familiar with the sounds/callouts for it.

If all the solenoids work and fire in the proper order, the connectors to the sound board are 100%, it is probably that 4049 chip that buffers the sound call inputs. One blown gate and then could have half of the input patterns would result in wrong sounds.

I suppose the PIA on the sound board could have a problem and since it is in a socket, that is a pretty non invasive thing to try if you have another known good PIA handy.

#10 6 years ago

MIL

Thrillhouse

I went ahead and ordered a logic probe but since I'm waiting on it I went ahead and socketed U16 and installed a new 4049 chip. No change in behavior unfortunately. I went ahead and swapped all the other socketed chips one by one with my working board and still no luck on a solution.
As I'm a huge newb at this; are all 4049 chips essentially the same even though they have different designations on them?
Should I try replacing the male pins on J1 or will that be a waste of time?
From reading Clive Jones' guide would U17 have anything to do with the issue?
Any and all suggestions are most welcome.

#11 6 years ago

AMS

barakandl

OP
Quoted from Thrillhouse:
I went ahead and ordered a logic probe but since I'm waiting on it I went ahead and socketed U16 and installed a new 4049 chip. No change in behavior unfortunately. I went ahead and swapped all the other socketed chips one by one with my working board and still no luck on a solution.
As I'm a huge newb at this; are all 4049 chips essentially the same even though they have different designations on them?
Should I try replacing the male pins on J1 or will that be a waste of time?
From reading Clive Jones' guide would U17 have anything to do with the issue?
Any and all suggestions are most welcome.

There are 4049B and 4049UB. In general its best to stick to 4049UB for pinball. I think either would work fine tho here on your S and T board.

If U17 had a problem i'd imagine the CPU chip on the sound board would be locked up. Looks like it does the chip enable decoding for the ROMs and what not.

I'd still do the logic probe test on the input signals. Maybe you have a bad connector pin?

1 month later

#12 6 years ago

???

Fordiesel69

Pinside member

Unknown

8y 45,400 363 26

Let me mention something rather simple that is easily overlooked. There is a capacitor C9 which is 470pf. It needs to be changed along with every single other capacitor on the board before spending another second. I have owned about 8 of these boards, and all screwy behavior was fixed by replacing the caps and on those with signal problems was solved by replacing c9.

Also make sure the 10k resistors are still testing good.

#13 6 years ago

AMS

barakandl

hrmm ceramic (or glass) caps like C9 don't really ever fail on me unless you blast them with high voltage or something. to kill the 10k resistors in series with the solenoid signals to the 4049 buffer would take some kind of major plugging in connectors wrong too. C9 is just there to eat any noise on the sol/snd bank select signal.

Have to say ive probably fixed 50+ squawk in talks in the last 10 years and I don't remember having to replace C9 once. The electrolytic caps, specially the 10uF and 1uF ones near heat sources, for sure do cause problems tho.

#14 6 years ago

MIL

Thrillhouse

Thanks guys for your help on this. I have a few prodject s&t boards and was able to rework a different one to get medusa going. I did get a logic probe finally, I'll check that board again and report back. barakandl you were correct in that replacing U17 did not solve the issue.

#15 6 years ago

AMS

barakandl