MK2 won't boot

gobsgraham

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So I couldn't get this to boot in a cabinet so I brought it inside to play with it. First thing I noticed was the battery was dead. I don't have a replacement but battery in or not it still wouldn't boot. Next I measure the 5V and it is only 4.59 volts on the chips. I adjusted the PS up to around 5.5 volts to get 5.1 on the chips. I assume that means something has a resistive short but I can't find it. Nothing really warms up after letting it sit for 5 minutes. When it does start with the voltage bumped up it freezes on testing scratch rams and stays there. Pressing the (what I assume is a reset or step button) shows various similar images to the third picture.

Any ideas where to go next. I have read through all of the the other MK repair threads and they don't seem like the same issue. With that being said I have yet to pull clean/sand/re-seat all of the ROM's and PLCC's.
 

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you have some pretty ridiculous resistance across your power wiring! (to have to jack it up to 5.5)

just cause it seems to cure many stupid problems with this game, pop the leftmost 2 rom chips out (these are the "game" roms) and ensure that there's no crud on the chip legs. if there is, some sandpaper and gentle sanding the shit off the legs should be suffice, then pop them back in and see what happens.

next I would inspect the back side of the board to make sure there's no pins from adjacent/nearby chips touching each other. it commonly happens on these boards and it's generally caused by the previous asshole that owned the game laying it on a flat hard surface with the PCB mounting feet removed. what then happens is the longish legs from the components bend over and start touching each other. at which point you can either take electronic shears and snip the excess portion of the legs off (to prevent it from ever happening again) or you can manually bend them back away from each other (most likely with a precision flathead)

a question for you: did this game ever work for you?
 
I bought it in a warehouse raid of 120 games and it never worked. The rom test image is the first time I have ever seen it do anything. I got the original Polo working a week or two ago so I started to turn my attention to the board to see if I can save it.
 

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I would definitely start with re-seating the various roms and making sure the legs are nice and clean as mecha said. That memory expansion board has also been known to be finicky and cause issues so I would re-seat that as well. Good luck. A dedicated MK2 is well worth saving. If you plan to sell it I don't think you'd have a ton of trouble.
 
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