cab and game problems

[newlands1]

have two jamma cabs tryed the same game in the two cabs. and one is ok with the game but other is not

cab (1) this is the one the game is ok . test the 5.v on the jamma conector and it says 5.12. and on the game board at the jamma fingers it reads 5.12. as i say game plays ok on this

cab (2) this one the game problems r screen pulls sightly down at parts.and u can see like 3 pencil lines one the screen. test the 5.v on the jamma conector and it says 5.20. and on game board at the jamma fingers it reads 4.90. ... any ideas guys . i have swaped with a other psu unit and everthings is the same

 

[karlcdoe]

test the 5.v on the jamma conector and it says 5.20. and on game board at the jamma fingers it reads 4.90. ...

well, assuming it's been measured correctly (eg are the jamma 'fingers' oxide free) then it sounds like a bad edge connector or wiring between the two points you have measured. Having said that some voltage drop is probably normal. Assuming the loom/conenctor aren't utter cack then you could try adjusting the power supply until you get 5 volts at the board itself just don't overdo it or you'll fry the logic.