Need help Satellite D660 not CHARGE

[gcomputers]

Hi i m working with this toshiba LA-7201p come to me with not charging problem.
I find that ic PU330 not have voltage changed it OK charge for one moment after it makes a little noise and stop charging
-BURNED PQ204
-Batt+ is shroted now

Its the second board with the same issue change pu330 and after burn pq204 .

For one thing i'm not sure because i replace RT8205LARGER with TPS51125 ?

Any help please

[rievax_60]

Re: Need help Satellite D660 not CHARGE

I had a lot of trouble lately cause by a fake IC from an Aliexpress seller.
The fake part is on the left. Notice that the texture of the top looks wrong like it has been ground down.

[gcomputers]

Re: Need help Satellite D660 not CHARGE

Thanks rievax_60 i replaced again the ic 51125 with an used taked from an motherboard , but the same short now when i plug power with powersupplylab 2v 5 a CPU
heats up . removed CPU short go (no more short) bound together PQ204 pin 123 with 5678
and now burned PU450 tps5117 now i try to replace it.

[gcomputers]

Re: Need help Satellite D660 not CHARGE

replaced PU450 but burned PQ451 replaced it but burn again when plug in power adapter.
Any help please.

[rievax_60]

Re: Need help Satellite D660 not CHARGE

Although this is of little help to you now, most laptop mainboards have a protection system that prevents the VIN MOSFET(PQ204) from being turned on if there is abnormal current drain on B+. PR1, PR2 and PR3 pass a limited current from VIN to B+ on page 42. Comparator PU2B needs to sense a certain amount of voltage rise on B+ for it to allow ACON to go high which then turns on PQ204.

[rievax_60]

Re: Need help Satellite D660 not CHARGE

When a MOSFET fails, it is possible that the control IC is also damaged. I usually check for a normal brief burst of gate drive pulses with a DSO before fitting a new MOSFET. Always check the lowside MOSFET. There are many places where 19v is converted to a much lower voltage by buck regulators. When a highside MOSFET shorts, the whole 19v tries to apply to the low voltage rail, which would destroy everything. The control ICs usually have Crowbar Protection which sense this over voltage and turns on the lowside MOSFET in an attempt to clamp the output rail down. This can damage the lowside MOSFET also.

[rievax_60]

Re: Need help Satellite D660 not CHARGE

I never apply more than 1v to B+ when finding the cause of an abnormal current draw. Keep in mind that you might be applying test voltage directly to a low voltage rail via a shorted highside MOSFET.

[gcomputers]

Re: Need help Satellite D660 not CHARGE

hi to all.
I did some works on this mobo , changed PU450 , after burned Pu150 replaced it , also replaced Pq151 now ,
the PROBLEM IS B+ is shorted because shorted PQ451 without it no short replaced also PQ204 ok
NOW WITH PQ451 REMOVED CHARGE OK POWER UP, FAN RUNS, BUT NO DISPLAY , NO VOLTAGE ON COILS OF CPU (28OHMS 0 V WHEN I TURN ON 98OHMS 0V), CPU IS COLD .

pq451 is the problem , around pu450 i have 5v .

Any help please

[rievax_60]

Re: Need help Satellite D660 not CHARGE

To me it looks like the regulator with PQ451 supplies the graphics. Do you know why so many MOSFETS were damaged? Was high voltage applied to the mainboard?

[gcomputers]

Re: Need help Satellite D660 not CHARGE

The customer said that only not charge, there is no sign of liquid....
mosfets have burned one after the other, before I changed PU330, after this charge 30 sec and burned PQ204, changed burned again, shorted B+....
Apply 1v on B+ but no heat anything AFTER

I checked and find burned PQ451 removed,

I try connected together pin 123 5678 of PQ204 , and is heated too PQ151 and the PU150 replaced , now charging ok but without PQ451 when i put in pq451 go in short B+ ......................

[rievax_60]

Re: Need help Satellite D660 not CHARGE

Is the AC adapter outputting the correct voltage?

[gcomputers]

Re: Need help Satellite D660 not CHARGE

Is the AC adapter outputting the correct voltage?

Thanks for your reply , but i closed the laptop because the customer does not want to wait more.
anyway i find ISL95831 PU500 pin 35 UGATE2 from here provide the short , , However, i had no part to replace and costumer don t wait.

Anyway thanks