Over Suppled voltage on Logic Board

[DomDom]

After recapping my logic board and plugging it into the analog board the voltage for the 5-volt rail was set way too high like 6.5v (I was able to measure before it shorted) and then as I was measuring voltages snapped and Mac turned off. Now the 5-volt rail is shorted to ground. So it seems like an over-voltage shorted board so what chip or whatever probably got shorted right now the only things that get hot are the CPU, ROM (not the problem), and the VLSI chip. Anything helps thanks!

 

[bibilit]

Willing to help, but i cannot find anywhere in your post which Macintosh you have.

 

[DomDom]

Sorry a macintosh classic

 

[bibilit]

The MBR1045 Schottky Diode (DP6) is on the 5 volt line, have a look at it first for any short.

But voltage too high or too low is usually a sign of a bad optovoupler CN17, but alla lines are affected

 

[bibilit]

Please read « Optocoupler » and »all »