Re: Dell laptop LA90PE0-01 charger repair

Well, I know I 'm not that lucky. Second of charger in the batch same symptom. Found the same 0 ohm resistor opened ... but nothing on this one. Chip has HV, VCC is 20V and drops to 15V. every second or so. Like it is trying to start ?. But I cant see ANYTHING in the gates .... nothing. Here is where I got lost. The PFC section is not supposed to work because of the chip ?. I mean, I got 300V on the main cap. But the PFC mosfet is doing nothing ..., at least no activity on its gate. I will re-read above for tips in case I missed somethi...

Re: Dell laptop LA90PE0-01 charger repair



Could be, but in this case are related to the optocoupler cricuitry (output side) I dont tink that the current could be that high....

Re: Dell laptop LA90PE0-01 charger repair

I just registered to thank you for the solution. It helped with my DELL charger as well. Done some measurement. I concluded that the chip was good since the PFC was OK, I got 300V no problems. but measuring arund the optocouples ... got lost. I found a 0 jumper opened. Wondering if the boar design, that has two major holes to fit the low profile transformers (on coil and one transformer) just weakened the board and could crack SMD components. Could be the reason for the silastic flood (YES ... I spent a lot of time cleianing this LOL). ...