820-00165 no power

[andrew boren]

yes i have 3.3v on l7560

 

[dukefawks]

Could be corrosion anywhere. Check the usual suspects, U1900, U1950, J6100, U6100 and termination resistors/traces.

 

[andrew boren]

where does PP5V_S4RS3 come from and what can i do to create it? i checked all 4 locations only thing i noticed out of place was r6117 was disconnected, from both sides. replaced and retraced, and i have 3.3v running threw it now, but still no change. sucky part is that it was working, once i ran the line. it powered, now something somewhere else went out and i feel it may be internal.

 

[dukefawks]

The whole power cycle is not even starting if you have no pulses on 5V rail. Could be SMC, CPU or anything in between. This one will suck. Make VERY sure you have no pulsing or even one pulse when connecting power. Pretty impossible to catch on a slow multimeter, use a scope.