and555 писал(а):
please check PU4702/PU4704, i think one of them is shorted.
Already replaced PU4702 found short for the 2nd time, though PU4702-4703-4704-4705-4707-4708 were replaced before.
Measured Resistance to GND on PL4701
without CPU,
found 87 Ohms , very low!
Removed one leg of coils PL4701 PL4702 PL4703,
found with GOOD SURPRISE 0.180 kohms resistance to gnd (before and after the coils),
that's ok.Re-soldered coils, and measured again coils'resistance to GND found 0.220 kohms, still good!
I couldn't understand why coils'resistance to gnd became normal, just after removal of one leg and resoldering it back ? I guess some discharge took place when legs were removed!
Now, when lap plugged in, lights ok and fan continuous spinning, but no display.
Will change the 4 failing caps and PU4702 and see.