cps2 volume resets when powered off for a while

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

Post by leonardoliveira » June 24th, 2017, 4:42 pm

Have you tried replacing the supercap? Could be the fault I mentioned a few posts above. That's a fault condition, not a circuit design error (the case with the wire patch).
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Re: cps2 volume resets when powered off for a while

Post by VectorGlow » June 24th, 2017, 6:17 pm

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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Re: cps2 volume resets when powered off for a while

Post by leonardoliveira » June 24th, 2017, 10:00 pm

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 » June 24th, 2017, 10:38 pm

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 » July 5th, 2017, 11:15 am

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

Post by crmb » December 6th, 2018, 8:27 am

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

Post by nem » December 6th, 2018, 3:39 pm

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 » December 6th, 2018, 9:51 pm

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 » December 8th, 2018, 1:05 pm

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 » December 8th, 2018, 2:23 pm

Interesting.

So technically you could test this just by removing the super cap.

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