CPS2 Multi 5v issue? ["FIXED"]

Hello

I own an older version of the Darksoft CPS2 multi and it always worked well, except during at least the last year I noticed I had to bump up my cabinet 5V to make it work otherwise it would boot up to a dark screen. I don't really remember it happening before, even if I always check my 5v before changing pcbs. I'm posting now because it may have become worse, feels like I need to turn it up even more than before idk.

Is this a normal behaviour of the multi or my power supply is getting tired? Or maybe I have an issue with my CPS2 board? I don't see anything similar with any other multi/pcbs.

Thanks for your help !

Meubeu said:

I always check my 5v before changing pcbs.

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That’s incorrect, every pcb is going to have a different resistance, so you need to adjust the psu after changing in a new one. Always adjust the psu so that the PCB is receiving 5.00v, measured at the jamma edge, while it is plugged in and powered.

View: https://www.youtube.com/watch?v=hzEwX9ak6qg
at around 4:30 starts discussion but you can see that an empty jamma harness dialed in at 5.2v will drop to 4.96v after a taito pcb is plugged in. That's -.25v, and I'd expect the cps2 multi to show a drop even larger than that. If you're starting at 5.0v on an empty harness, then plug in the cps2, you're probably ending up somewhere around 4.6v or 4.7v which will cause issues.

Every power supply will be a bit different. Every pcb will be slightly different, you just need to measure after changing pcbs. Lots of folks will buy a voltage meter to put on their jamma harness to make it easier.

CPS 2 consomme beaucoup, c'est peut être ton alim qui fatigue, l’écran noir en dessous 4.6V c'est normal.

CPS 2 consumes a lot, it may be your power supply that is tiring, the black screen below 4.6V is normal.

@ekorz

ekorz said:

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Thanks a lot for your input, indeed I had a misconception of this because of things I heard and things I misunderstood most likely. Although from my testing it seems to drop much below 4.6 on my CPS2, so maybe it's my power supply that is in need for a check.

@nonosto merci aussi, en effet je pense que mon alim est en perte de vitesse je crois pas qu'elle a été révisée depuis que je l'ai donc c'est une forte probabilité

Meubeu said:

Thanks a lot for your input, indeed I had a misconception of this because of things I heard and things I misunderstood most likely. Although from my testing it seems to drop much below 4.6 on my CPS2, so maybe it's my power supply that is in need for a check.

Click to expand...

Your psu is probably fine.
It is worthless to measure the voltage without a pcb plugged in.

Connect any pcb
Turn on the power
Adjust the 5v line to 5.000v measured at the jamma egde

Do this every time you switch boards, it will be different for every pcb.

Also if you get one of those in-line volt meters, make sure to verify its measurement using a known good and reliable multimeter at least once.

I do have one of those (known to be unreliable?) in line volt meters you need to solder on the jamma (in my case I used an extender), I checked with my multimeter and it seems ok though. I guess I was overthinking because I suddenly had to push the 5v farther than usual to make the multi work.

Thank you guys for your advices.