asus k55a no display

[rickybucalan]

hi guys i got here asus mobo. can somebody see and help me pls... i got those voltage in coil and one is missing. what might be the problem?

[masud]

Re: asus k55a no display

which voltages u got?

[dycc]

Re: asus k55a no display

intel graphic voltage is missing (0.4v or 0.5v ). on some HP model reflow southbridge or flash bios can solve this issue

[dycc]

Re: asus k55a no display

hi guys i got here asus mobo. can somebody see and help me pls... i got those voltage in coil and one is missing. what might be the problem?

CPU also can be bad as you don't have dedicated gpu on this board . don't ignore the (DC-DC) chip who supply this voltage can also be bad . good luck

[rickybucalan]

Re: asus k55a no display

0v on single big coil near cpu socket. the rest are written on the picture..tnx

[rickybucalan]

Re: asus k55a no display

intel graphic voltage is missing (0.4v or 0.5v ). on some HP model reflow southbridge or flash bios can solve this issue

thanks

where exactly could i find that voltage? i did mild reflow on S/B chip and doesn't work. do you think its bios problem?

[rickybucalan]

Re: asus k55a no display

CPU also can be bad as you don't have dedicated gpu on this board . don't ignore the (DC-DC) chip who supply this voltage can also be bad . good luck

ok i will try that thank you....

[diif]

Re: asus k55a no display

Hi, did you find a solution to this ? i have an identical laptop with the same missing voltage.

[dj_ricoh]

Re: asus k55a no display

Hi, did you find a solution to this ? i have an identical laptop with the same missing voltage.

did you try another cpu?

[diif]

Re: asus k55a no display

did you try another cpu?

No, but i have found a couple of Mosfets that don't seem to have the correct voltages.
19v on the Drain with no voltages on the Source or Gate of the mosfet on the rear (4955N) and 1.6mv on the Source on the front (4936N) mosfet.

[diif]

Re: asus k55a no display

I forgot the photos

[diif]

Re: asus k55a no display

I have tried a replacement CPU and still the same issue. DC-DC chip problem ?

[ktmmotocross]

Re: asus k55a no display

remove coil and check for short.

[diif]

Re: asus k55a no display

By measuring the resistance between ground ?
Nothing on the back.
The two diodes next to the cpu show a short until i remove the cpu, is this normal ?
Source of the 4939 is to ground also.
I'm not quite sure what i'm doing, your help is much appreciated.

[martin319831]

Re: asus k55a no display

Hi all
I've got similar problem, I've got picture but no backlit. HDMI and CRT work fine. Because I cannot find motherboard schematic it makes it even more difficult. I've checked all lcd pins and I've got 19V, 3.5V, 1.3V, 1V and 0.3V. Can anyone help please?
P.S. I've tried 3 different LCD screens.
Thank you