MV1AX Watchdog Click of death

[brian.illsley]

Hi all, I have a MV1ax motherboard that has the watchdog click of death, this has come directly from a arcade breakers and looks like its in relitivly good condition (bought as a job lot). This board has no discernable corrosion or broken traces. But it does have a lot of the small smd capacitors missing on the rear of the board. PC9, PC11, PC13, PC14, PC22 and PC33. would this cause the watchdog as I have another MV1C that also has 3 missing PC capacitors and that works fine? also what value of the said capacitors or am i looking in the wrong place.

What would I start with as diagnostics for this board? im just a begginer and bought 3 boards, one that worked and two broken ones so I could learn, one of the orther broken ones I got to work, so im looking for help for this next one.

Thanks guys

 

[maki]

missing PC caps on the bottom usually means that they been ripped off by force, check for damaged traces there first, bent pins that are shorted etc.
if that looks good I'd move on to check that each BIOS pin has connection to the 68k

PC = power conditioning, they re not required, them missing should not cause a click of death
IIRC they are 68nF ceramic caps, but 100nF will do just fine

 

[channelmaniac]

Click of death = stuck in watchdog reset. Board can't boot. Problems could be anywhere - RAM control lines, damaged address bus traces, damaged data bus traces, bad RAM, bad BIOS ROM, bad CPU, bent pins, corroded or gouged traces, and the list keeps going.