toshiba satellite c660d-13h no power problem

[chriscute42]

hi
i have toshiba c660d-13h laptop with PWWBE LA-6849P rev2 motherboard.
no power problem.
when i attach the charger, the green led wont turn on.
please help!
thanks.

[Agent24]

Re: toshiba satellite c660d-13h no power problem

Potentially silly question, but I assume the charger is known to be good?

[chriscute42]

Re: toshiba satellite c660d-13h no power problem

yes, the charger is working and have supply to motherboard!..

[chriscute42]

Re: toshiba satellite c660d-13h no power problem

Before this laptop got no power, it’s always hang so I try to reformat the operating system and have same problem. Then I try to clean ram and replace new, have same problem. Then I try to reheat the video ic, when I put it back the motherboard have no response. Plz, help.

[Agent24]

Re: toshiba satellite c660d-13h no power problem

I can't see a schematic for this board anywhere easily, do you have one? How much experience do you have in repairing laptop boards?

Also, can you post photos of the board?

[chriscute42]

Re: toshiba satellite c660d-13h no power problem

Here is the sample picture of motherboard, sir.

[chriscute42]

Re: toshiba satellite c660d-13h no power problem

I have a little bit experience in repairing laptop board.
plz help, sir.

[xxxvirus1987xxx]

Re: toshiba satellite c660d-13h no power problem

i think the mother board has no problem before
it always hang because maybe yuor hardisc have a bad sector you can fixed it using hdd regenerator..
since their no response any more
firts step reset cables...reset bios or try to hang the cmos battery atleast 10 seconds then power on again..
maybe the motherboard also han loose solder since you reheat gpu.

[chriscute42]

Re: toshiba satellite c660d-13h no power problem

No problem on hdd, sir. Because I already replace hdd before I reheat the video ic. When I install the driver of video and restart the system its hang on the logo of windows 7, so I decide to reheat the ic.

[chriscute42]

Re: toshiba satellite c660d-13h no power problem

I try to test the diode and fuse of the motherboard its works ok and there is a supply came from the charger going to the pin of motherboard.

[xxxvirus1987xxx]

Re: toshiba satellite c660d-13h no power problem

i think we need scheamtic for this to trace the line correctly wher is goes....
if the voltages are correct waiting for others to help....tanx

[ktmmotocross]

Re: toshiba satellite c660d-13h no power problem

chceck pins of mosfets right behind the ffuse or on the other side of board right to the fuse

[chriscute42]

Re: toshiba satellite c660d-13h no power problem

sir ktmmotocross, Can you help me how to test if the mosfet is working or not? I don’t know how to test it using a tester.

[ktmmotocross]

Re: toshiba satellite c660d-13h no power problem

just chceck voltage on its pins

[xxxvirus1987xxx]

Re: toshiba satellite c660d-13h no power problem

if the mosfet has three legs it is very easy...
find firts the pin
gate
source
drain
Connect the 'Source' of the MosFet to the meter's negative (-) lead.

1) Hold the MosFet by the case or the tab but don't touch the metal parts of the test probes with any of the other MosFet's terminals until needed.

2) First, touch the meter positive lead onto the MosFet's 'Gate'.

3) Now move the positive probe to the 'Drain'. You should get a 'low' reading. The MosFet's internal capacitance on the gate has now been charged up by the meter and the device is 'turned-on'.

4) With the meter positive still connected to the drain, touch a finger between source and gate (and drain if you like, it does not matter at this stage). The gate will be discharged through your finger and the meter reading should go high, indicating a non-conductive device.

Such a simple test is not 100% -- but is useful and usually adequate.

When MOSFETS fail they often go short-circuit drain-to-gate. This can put the drain voltage back onto the gate where of course it feeds (via the gate resistors) into the drive circuitry, possibly blowing that section. It will also get to any other paralleled MosFet gates, blowing them also.
So, if the MosFets are deceased, check the drivers as well! This fact is probably the best reason for adding a source-gate zener diode; zeners fail short circuit and a properly connected zener can limit the damage in a failure! You can also add subminiature gate resistors -- which tend to fail open-circuit (like a fuse) under this overload, disconnecting the dud MosFet's gate.

[smali]

Re: toshiba satellite c660d-13h no power problem

Check voltage on PQ204

[polytek]

Re: toshiba satellite c660d-13h no power problem

hi,
it hppend to me with two laptop, and there is no power problem , just check the resistantce of the graphic chip that you have reflowed if you find 000 OHM you have to try to heat the chip carefully to take out the short, but if there is no short, just clean the flux under the chip and it will work,
good luck, hope i will help you to repair this borad;

[xxxvirus1987xxx]

Re: toshiba satellite c660d-13h no power problem

i agrre to mabroukmedal you need to reheat again the video chips maybe their is a lose connection or short you must inusure it @ 100% good contact before you start trouble shooting....the mobo.

[chriscute42]

Re: toshiba satellite c660d-13h no power problem

thanks, i try it.

[hansie55]

Re: toshiba satellite c660d-13h no power problem

This is what I could find in archive