Neo Geo Six Slot Clicking

Hey guys,

I just picked up a 6 slot motherboard and when I power it on a clicking sound comes from the speakers about twice a second (Jumbled blocks appear on screen and change with the clicking).

It does not boot up and I can't do anything with it.

Seller claims to have removed the battery himself several years ago, and the board has been sitting in his closet since. I have not yet replaced the battery.

I did some searching and found a repair place that offers their repair logs. This is what I found

"Neo Geo MVS system is dead - has clicking from speakers This system powered up but never appears to start its self tests. The clicking sound from the speakers meant that the watchdog circuit was resetting the CPU in an attempt to kickstart the system. Replaced the lower work SRAM IC to fix the board."

Is this a chip that I could just purchase and replace myself. Does anyone here offer this chip?

Thanks for the help.

How are you powering it?

It's actually in my 4 slot cab.

Do you think it's not getting enough juice?

Nah it should be. Check for corrosion or broken traces. That repair log site I believe is RJ's (channelmaniac) newlife something I think.

I think you're right about it being his site.

I'll take a closer look at the board tomorrow when I'm not risking waking everybody up. I'll probably shoot him an email, too

Man, this is the worst ebay deal I've had in a while - One dead 6 slot and two boots.

Hey!

Glad someone's getting some good use out of my repair logs

However, that problem could be caused by multiple issues. Anything that keeps the CPU from accessing the work RAM, backup RAM, or BIOS will cause that.

If you have a logic probe then check the CS*, CE*, and R/W* pins on the backup RAM chips to see if the signals are there. If they aren't you'll get that click of death. The backup RAM is the RAM that has no continuity from pin 28 to the +5v pins on the JAMMA connector.

Next check the same pins on the work RAM.

Next check the BIOS for bent pins.

After that, there are a few more things that could be checked such as continuity between the CPU and the BIOS ROM and the work RAM and the backup RAM. This will have to be checked before condemning the RAM chips.

I sell the 62256 SRAM chips on my site. These are surface mount chips that require special care to replace. It's easy to really screw up the board if you don't know how to remove and replace them.

http://www.arcadecomponents.com/catalog/item/2251646/4758714.htm

I also offer repair services on the boards. $35 flat rate for non-surface mount and $40 for surface mount. This doesn't include top board repairs, slot connectors, or batteries.

RJ

Thanks for all the info!

I'll have to check some of those things next time I have a free day. Although, after consolizing a bunch of MV-1Cs, I think I'm just about done with surface mount chips

I may just have to get in touch with you about a repair in the near future.

Have a good one.