cps2 volume resets when powered off for a while

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VectorGlow
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Re: cps2 volume resets when powered off for a while

Post by VectorGlow »

I haven't tried to replace the supercap as I was going on the assumption that if it was faulty then other settings would be lost or corrupted after powering off, and that isn't the case.

At least that's how I see it - what do you think? :)
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leonardoliveira
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Re: cps2 volume resets when powered off for a while

Post by leonardoliveira »

Game settings are stored in a EEPROM. Nothing to do with the supercap which keeps power only for the volume control IC.
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Re: cps2 volume resets when powered off for a while

Post by VectorGlow »

Ahhhh, I see. I had stupidly assumed that the supercap was keeping power for all settings.

My bad.

I'll see if I can source a replacement then - I usually order my electronic components from Farnell or RS so hopefully they'll have something suitable. I'll open up the shell of the A board again tomorrow and check the existing supercap's values.

Thanks very much for your help and advice. :)
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Re: cps2 volume resets when powered off for a while

Post by VectorGlow »

Update: Replacing the supercap fixed the volume settings problem. Thanks for your help. :)
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crmb
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Re: cps2 volume resets when powered off for a while

Post by crmb »

I have issues with my SFZ3 980629 CPS2. I plugged it yesterday (haven't used it for a few years) and the sound was very low (RCA as well as JAMMA). I think i already had this issue, and maybe the VOL- hold during power fixed it (but can't remember for sure).

I tried several time but it doesn't change anything. I also uplugged/replugged the A/B boards. The volume shown in the test menu is "39" (max). I made a reset.
Also, is the TEST button supposed to do something ? Because the three buttons doesn't do anything.

I tried again today, and after a few try, i don't have sound at all anymore.

Do you think i can try to change this "supercap" ? I opened the A-Board and everything looks pristine.
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Re: cps2 volume resets when powered off for a while

Post by nem »

The supercap just keeps the settings saved. Unfortunately that won't help you, since your problem is that you have no audio at all. Your problem is a faulty amp, op amps or caps.
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Re: cps2 volume resets when powered off for a while

Post by crmb »

Thanks. I checked my PSU (blast city) voltages and they are fine.
I hope the PSU is not frying everything because my gdrom also start only when he want to.

This is pictures of my A-Board. I will try to buy another to make tests. Is there anything i can try to troubleshot with my multimeter ?

About the TEST button on the A board, is it supposed to do something ? And when i push VOL UP or DOWN, am i supposed to see the level change in service sound test (jukebox). I can't have anything other than 39. I wonder if the buttons are working

edit: wow a-board are expensive now...

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Re: cps2 volume resets when powered off for a while

Post by leonardoliveira »

That problem is likely caused by corrupted data inside the volume control chip. Data corrupted because the supercap isn't holding enough voltage to make the data survive a power cycle, yet it's not low enough to make it fully "evaporate". You have to replace the super cap. It's the small device with a Matsushita logo ( [M] ) which looks like a small battery near the TOSHIBA TC9185P IC. The big capacitor near the RCAs is a regular capacitor. It's big but not super (lol)
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Re: cps2 volume resets when powered off for a while

Post by nem »

Interesting.

So technically you could test this just by removing the super cap.
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Re: cps2 volume resets when powered off for a while

Post by crmb »

OK i thought the biggest was the "supercap"
I shorted the M cap (it was at 3.6v) until it gave almost 0.05v but still no sound when booting.
Do you think it can still be the issue and worth to unsolder it ? (can the game boot without the cap ?)
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Re: cps2 volume resets when powered off for a while

Post by nem »

It's not your issue.
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Re: cps2 volume resets when powered off for a while

Post by crmb »

I will buy another board to check the game. Anyone around fixing CPS2 in europe ?
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Re: cps2 volume resets when powered off for a while

Post by NoAffinity »

VectorGlow wrote: June 23rd, 2017, 6:23 pm I've looked through this thread and see the supercap mentioned, however other system and game settings are being retained just fine so the supercap must be okay, the EEPROM in that case should also be fine.
The supercap is part of the audio circuitry only, has no effect on other settings. Your problem is likely the supercap.
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Re: cps2 volume resets when powered off for a while

Post by crmb »

I got a new motherboard and the sound is working. I wanted to be sure the game was ok before bothering trying. I will try to remove the cap.

edit : i noticed the TEST side button was also working on the new a-board. (it was not on my defective a-board but nobody told me if it was normal or not).
Jamma TEST pin is set correctly to GRND when pressing TEST on the cab, but not with the TEST button on the board (switch on bare motherboard). I looks like the three switches may actually be dead ! (not the green plastic part but the switches themselves)

edit 2 : it was easy to check since vol+ and vol- are also on the kick harness. Indeed the 3 switches are dead. I put the sound back with vol+ on the kick harness pins

Where to find replacement switches ?

PS : picture of the new a-board, is this any better than my old one (picture few post above) ? seems to be a newer rev.
https://i.imgur.com/waVFjZN.jpg
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Re: cps2 volume resets when powered off for a while

Post by NoAffinity »

So, the original A board actually works fine, with the exception of your test and volume buttons on the board not working?
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Re: cps2 volume resets when powered off for a while

Post by crmb »

Yes. It seems suspicious that all three switches are dead but it looks like it.
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Re: cps2 volume resets when powered off for a while

Post by nem »

Look into the ground connection. Who knows, it might be cut at some point before the buttons. That could explain it.
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Re: cps2 volume resets when powered off for a while

Post by undamned »

crmb wrote: February 2nd, 2019, 1:43 am Yes. It seems suspicious that all three switches are dead but it looks like it.
It's not entirely surprising to me. Those switches are notorious for being flaky or flat not working (likely due to dust/smoke build-up on the internal contacts). You could try shooting some non-lubricant "contact cleaner" into them and wiggling them all around to try to break up any rubbish inside them. If that doesn't do the trick, try this:

- Solder a piece of wire to GND
- Solder a piece of wire to the TEST button signal
- After the game is running, touch them together and see if TEST menu comes up

If it works, you know your switch is shot.
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Re: cps2 volume resets when powered off for a while

Post by crmb »

Hello there.
Finally i had time to try with wd40 contact cleaner and it fixed all 3 buttons!! I am really surprised. I wonder how it was inside the buttons, because i really pushed them a lot of time during my tests. (The test button never ever worked once.)

Thank everybody for your suggestions.
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Re: cps2 volume resets when powered off for a while

Post by crmb »

and.... it doesn't work again. None of the three buttons. At least the volume is stuck at 39 (max) this time.
Maybe the rubbish inside the switches "hardened" again since.
I will try the contact cleaner again next time i get volume issues or replace the switches eventually
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