Weird issue with my Moonwalker board

elekTRONarcade

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I just received my Moonwalker board today, bought as partially-working. Originally, the board supposedly only had a no-sound issue. Game went through the ROM/RAM test fine, coined up fine and started playing. However, MJ's movement animation was missing (floated around the screen), and the first time you used his attack or he was hit by an enemy, he would freeze in place (yet was still able to be pushed around when enemies bumped into him). The enemies, once he freezes, also stop firing and just move around the screen.

Any ideas what could be causing the issue?
 
Checks

What have you checked?

Connections
Voltages
Clean with electroincs cleand and.. remove all Socketed Chips - RAM / ROMs

Then perhaps Re-cap the PCB.
 
Checked all voltages and connections, which seem to be fine. Haven't cleaned/resocketed yet, that's on my todo list. Some of the caps, I dunno...they don't necessarily look off, but I can't tell if they're very slightly swollen or if its just the way these particular caps were manufactured. I may have to do a complete recap, along with a resurrection kit just to prevent it from suiciding
 
Cleaned/resocketed all chips on main and game boards. Fixed a loose cap on the game pcb. Plugged it in, and still the same symptoms. No sound, missing MJ animation and freezing of character.

Does anyone have any details technical bulletins, repair logs or schematics for Moonwalker? I have the manual but its next to worthless.
 
Quick update....I found a guy on eBay whose selling a board that does the exact same thing as mine...no sound and freezes soon after start.

Moonwalker on eBay

Is this a common occurance with Moonwalkers?

I would look into the sound issue as it is probably something is not getting voltage or a part is shorting out causing the game to lock up.

This is a newer type board and is more difficult to repair, requires more specialized equipment.

I did a search for the schematics and only came up with the manual so not much help there.

The only thing I can think of is to check for voltage at the audio amp and see if that is working. You might also feel around to see if any of the chips is getting hot, including the audio amp.
 
UPDATE 2: Seems I've learned more about Sega System 18 boards in the past two hours than I cared to know lol. It seems that this *may* be an issue with the suicide battery. When the sound CPU's battery dies, the sound simply stops working. When the main CPU dies, all hell breaks loose and the boards effed. Freezing and glitches may be because the CPU battery is dying. The game needs to be phoenixed, like CPS-2 boards. I'm ordering a replacement kit from segaresurrection.com tomorrow and hopefully that will solve the issue.
 
My Moonwalker was bought as scrap, it had an odd fault where the MJ sprite would not animate, drifted around the screen in the crouch position, sometimes freezing completely, the sound was also either completely missing or just a jumble of tones. The fault was someone had removed and replaced the PAL chips, and got them back in the wrong places, depending on how they are mixed up I could see how this fault could be related. Some PALs I could ID by googling their 315-xxxx number and were clearly wrong, like the Z80 related PAL being miles away from the Z80 ( this would cause the farked audio), but I could never find a definitive list for the 6 PALs on this board, but after a bit trial an error with the few I could not get info on I found the right combination. Here is where they need to be.

IC65 = 315-5430
IC62 = 315-5375
IC74 = 315-5374
IC72 = 315-5389
IC80 = 315-5391
IC97 = 315-5390

I ended up de-suiciding it as the game would crash when the foreground rolled back as MJ entered the arcade level, am guessing that section used an opcode for the 1st time and the decrypt table had bit rot. With the PALs in the right places and a stock 68000 CPU onboard it has been good for 4 years now.
 
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