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Main => Main Forum => Topic started by: arizonacats on December 31, 2003, 01:07:15 pm

Title: Power Supply?
Post by: arizonacats on December 31, 2003, 01:07:15 pm
I've been reading these boards for a long time, waiting for my chance to get involved.  Well, for Christmas, I got an old (and not working) X-Men: Children of the Atom upright! :D Seeing as it's my first hands-on experience with an arcade game, I'm not 100% sure what the problem is, but I think I've narrowed it down to the power supply (I'd like to see if it all works before I start changing things).  The monitor turns on (and I can flip the test jumper to see that it works) but I hear nothing else from anywhere in the cab (no fans moving in the power supply or in the CPS2 board).

I haven't run any actual voltage tests or anything, just basic wire connection checks, but I guess my question is - wouldn't a bad power supply cause this problem?  It was manufactured in 1991, and I'd like to replace it anyway as it's filthy.  Also, it's rated at +5V/15A, -5V/1A, +12V/5.5A.  How far can I differ differ the amps without causing damage?  I know I can increase them, but what about less amps?  That seems like it can't be good.  I was thinking about a power supply from Happs with a remote on/off switch (because the current one has one), but it only has 0.5 amps on the -5V.  Would that even work, or would it cause damage?

Sorry for the lengthy post, but I am so excited to get started that I wanted to get it all out at once.  I'm hoping to get some pics and such soon in case anyone cares to see them.  Thanks for your time and any help you guys can offer me!
Title: Re:Power Supply?
Post by: OSCAR on December 31, 2003, 02:25:40 pm
I am not sure how much current the CPS2 boards draw on the -5V line, but I believe that the Happ power supply with a .5A rating should be just fine.  Many of the game boards I'm familiar with have very little draw on the -5V, and a guy I know that owns an arcade told me he uses Happ power supplies in all his games, so it should work fine for you.

A bad power supply could certainly cause the problems you describe, and they are also the #1 point of failure for most arcade machines.  Best to check the voltages at the game board connector, though, just to be sure so you don't buy a power supply if your problem is elsewhere.

Title: Re:Power Supply?
Post by: arizonacats on December 31, 2003, 04:35:03 pm
That's what I was hoping, but wanted to make sure with the experts.  :)

Do you guys happen to know of any links/threads dedicated to power supplies (in mame/arcade machines) that I could read up on?  Seems like everything I've found so far is pretty high level, and not very technical as far as the specs are concerned.  I don't want to try to find my old college circuits books...

Thanks again!
Title: Re:Power Supply?
Post by: kevin on December 31, 2003, 04:48:26 pm
If you're not already familiar with them, you should look up some information on cps2 suicide batteries. CPS2Shock (http://cps2shock.retrogames.com) is probably the best place to start.

Basically, some essential decryption info is stored in battery backed ram. Once the battery dies, the contents of ram is lost and no usable video signal can be retrieved from the board. I've read that the typical life of the batteries are 3-5 years with the cab off, and when the cab is running there is no drain on the battery.

Hopefully you just have a bad power supply, but it's probably wise to swap the battery once you get it up and running.

-Kevin