Re: Laptop problem (Acer Aspire 6920G)

Yes true. But the hot air was used at start but not too much to do a damage to the socket. At the end removed by destroy it with a tool and iron gun.

I did an optical observation to the socket and didn't find something bad.

I see on the market exists some socket testers but for mPGA478MN it just categorized pins for the address line, control line, standard voltage, Vcc etc

In the PDF file (pga478__p42ghz_512kb_400mhz_fsb.pdf) i guess have the same pin layout with my socket. It's on page 29. It's...

Re: Laptop problem (Acer Aspire 6920G)

Yes maybe the short is on socket. I have to test it. I'll find a 478 socket cpu tester. At the very start when remove the faulty NEC/TOKIN and replace it with the new maybe the hot airgun did a damage on the socket joints and for that didn't work at my first repair attemp.

Re: Laptop problem (Acer Aspire 6920G)

A correction: The voltage increase on cpu coils L501,L502 was happening only when the Q5,Q7 mosfets was removed (i remove them to test them out of mob). So i guess was normal that wrong high voltage. Sorry for that, forgot to mention it previous.

So the voltage on L501,L502 is 0.75V without cpu and 0V when i insert it (without power on, just insert it on stand by the voltage drops to 0V).

I guess the caps you mention me is the C535-C539 but they didn't put them on that mob, i guess was optional (pic attached)....

Re: Laptop problem (Acer Aspire 6920G)

thanks for the response

Without CPU:
L501 = 871Ω
L502 = 871Ω
L15 = 330Ω
L524 = 610Ω
L525 =1480Ω

With CPU:
L501 = 14Ω
L502 = 14Ω
L15 = 330Ω (no change)
L524 = 610Ω (no change)
L525 = 1480Ω (no change)

For Voltage:

Without CPU:
L501 = 0.75V - when power on jumps to 1.6V and increasing to 2.6V
L502 = 0.75V (same as L501)
L15 = 1.84V
L524 = 3.3V
L525...

Hello everybody,

Trying to bring back to life an old laptop and i'll appreciate for any help and advices.

All start when the NEC/TOKIN fail. The laptop was working without reboots when the second core was disabled by the OS. So i decide to replace it. I order one but when i replace it the laptop was showing blank screen.

Next step was to repair it with the smd tantalum capacitors. I wasn't carefull and by accident i put one capacitor wrong with opposite polarity.

After i put correct some other working 2x 470uF caps but...

Re: Acer aspire 6920g - no display issue after fix

I replace the NEC/TOKIN with 2x 470uF caps (used from other laptop). Also, replace the core voltage controller (ADP3208) and two mosfets (Si7686DP).

Now with the cpu attached when you press the power button the power light opens for a second and turns down. Of course no video. Also, the fan try to spin but stop immediately. Without the cpu the power light remains open and the fan spins.

I check all the system voltages (5V, 3V, 1.5V, etc) and it's ok. I test with other cpu and graphic card with the same...

Re: Acer aspire 6920g - no display issue after fix

Thanks for the reply. I'll try the smd tantalum capacitors. But i'm afraid it's something else.

Re: Acer aspire 6920g - no display issue after fix

I have the same problem on the same model (acer aspire 6920g). Had random restarts and i replace the NEC/TOKIN 0E907 with a new one. After i replace it i have no video (laptop screen, VGA and HDMI).

I test other NEC/TOKIN, cpu, memory and MXM graphic card but the problem still exists. So the problem must be on m/b. I test it only with m/b, cpu, memory, graphic card, fan, power button and an external monitor via VGA port. I try to power up the laptop while pressing the north bridge chip (Intel LE82PM965) with no result....