Toshiba C55-A-1F6 - PT10FG Rev 2.1 - brak napięć

Dzień dobry.

Dostałem laptopa: Toshiba C55-A-1F6
Płyta główna: PT10FG Rev 2.1
CPU: SR0WY

Coś było nie tak z zasilaczem. Podobno wydobywały się z niego dziwne dźwięki. Niestety właściciel wyrzucił już ten zasilacz.
Teraz po podpięciu zasilacza uniwersalnego, brak reakcji na włącznik, dioda na zasilaczu nie gaśnie.

Pobór prądu 0.01A

Opory i napięcia na dławikach z CPU

L8800 >2k O 3,22V
L8300 236 O 0V
L8004 2,1 O 0V
L8001 2,9 O 0V
L8002 3 O 0V
L8200 0,6 O 0V
L8701 26,8 O 0V
L8702 26,8 O 0V
L8100 15,1 O 0V
L8101 0,5 O 0V

Opory i napięcia na dławikach bez CPU

L8800 >2k O 3,22V
L8300 1,9k O 0V
L8004 >2k O 0,44V
L8001 >2k O 0,4V
L8002 >2k O 0,4V
L8200 0,5 O ?? 0V
L8701 26,2 O 0V
L8702 26,2 O 0V
L8100 16,2 O 0V
L8101 0,6 O ?? 0V


BIOS
1 0,10V
2 1,4V
3 3,26V
4 0V
5 3,26V
6 1,74V
7 3,26V
8 3,26V

KBC (bez CPU)
3 - 3,27V
11 - 0
12 - 1,8V
74 - 3,26V
101 - 0,1V
125 - 3,26V

mpowroznik ha scritto:L8200 0.5 O ?? 0V
L8101 0.6 O ?? 0V

Hello!
Remove the coils L8101 and L8200 from the board and measure the resistances to ground on both pins of that coils.
Is a short circuit to ground present on power rails "+3VO" and "+1.05VO" or on another side of that coils?

Hi,

After I removed power coils there is short on +1.05VO and +3VO, but there is no short on other side of coils.

On L8101
1 - 0,6Ω - short
2 - 1,07MΩ

L8200
1 - 0,6Ω - short
2 - 1,784MΩ

Perform a short circuit test described here on shorted pad of coil L1801. Limit the voltage to 3V.

I set a limit on voltage to 3V.

When I set current on 1A there was nothing I can feel. I started to increase the current. When I set 3A I started to feel warm from chip U2001 - SLJ8E. After a few seconds it started to be hot, but not very.

There wasn't any other source of heat.

I used also compressed air (upside down) and it starts hot under the core of that chip.

Everything is clear - the PCH chip (U2001) is definitely bad and needs to be replaced.

Now you can also perform a short circuit test on shorted pad of coil L8200. In this case set the voltage limit to 1V.
Check, if it will be warm something else, but this short is probably also related to the PCH chip.

By the way, your test wire is fairly thin. You may have to use a wire with a larger cross section. Usually it is need to use a wires with a cross section at least 1mm^2 for a short circuit test at such low resistance to ground.

Before I put back coils I heat up PCH.

Then I soldered coils and get back resistance on L8101 18,7Ω and voltage 3,26V, but still nothing on L8200.

When I connected AC adapter PCH is hot.

The PCH chip is damaged - it needs to be replaced. There is unfortunately no other option.

Thank You