Dell Inspiron N5050 No power & flashing Power led every 7 secs

[classicandy]

I have a Dell Inspiron N5050 not powering On and flashing Power led after every 7 seconds continuously.

I have changed CPU with the compatible ones listed in Dell site, still no difference. If i put the wrong CPU (not listed on Dell's site), it will power On and off after 10 seconds.

Please help.

[peste]

Re: Dell Inspiron N5050 No power & flashing Power led every 7 secs

have you checked anything else? ... give more details ..

[classicandy]

Re: Dell Inspiron N5050 No power & flashing Power led every 7 secs

have you checked anything else? ... give more details ..

Ok.

I have only changed three (3) MOSFETs PU4302, PU4305 & PU4308.

I'm suspecting CPU controller (PU4201) but I'm not certain it is the problem.

The previous CPU got damaged due to over heating or so. The thermal paste had dried up completely.

[piernov]

Re: Dell Inspiron N5050 No power & flashing Power led every 7 secs

Why replace those MOSFETs? Was B+ shorted to CPU VCore?

[classicandy]

Re: Dell Inspiron N5050 No power & flashing Power led every 7 secs

Why replace those MOSFETs? Was B+ shorted to CPU VCore?

Gate and Source were shorted for those three (3) MOSFETs

[piernov]

Re: Dell Inspiron N5050 No power & flashing Power led every 7 secs

Usually it would be a drain-source short.
Anyway, if there was a short there, I'd recommend replacing the MOSFET drivers at the same time as the MOSFETs. Maybe the controller too…

[classicandy]

Re: Dell Inspiron N5050 No power & flashing Power led every 7 secs

Usually it would be a drain-source short.
Anyway, if there was a short there, I'd recommend replacing the MOSFET drivers at the same time as the MOSFETs. Maybe the controller too…

ok. Is PU4201 the MOSFET driver or Controller?

[classicandy]

Re: Dell Inspiron N5050 No power & flashing Power led every 7 secs

https://www.badcaps.net/forum/showthread.php?t=62818

That thread is similar to mine but not solved

[piernov]

Re: Dell Inspiron N5050 No power & flashing Power led every 7 secs

Ah, I wasn't paying attention. PU4201 is the controller, but the drivers for phases 1 and 2 are integrated into it. Only phase 3 has a separate driver, PU4301.
So could be a good idea to replace both PU4201 and PU4301 if there was an issue with the MOSFETs…

[classicandy]

Re: Dell Inspiron N5050 No power & flashing Power led every 7 secs

ok. I don't think I can easily get a replacement now. I'll place an order for the I.Cs and report back my findings as soon as possible. Thanks.