Acer aspire 4752 white screen

[sasser]

Hye i got problem with this acer. Already reflow intel hm65, also change new lcd cable, the change too new led 14.0" still display white. Pls help me. Thanks a lot

[sasser]

Re: Acer aspire 4752 white screen

Update

Test mosfet three pin near lcd connector. I found fet with marked NE. And no reading when measured. Are this fet is problem?

[JaroTech]

Re: Acer aspire 4752 white screen

Hi, do you have a U4901 chip on the motherboard with the number 5285 on it?

[sasser]

Re: Acer aspire 4752 white screen

I will update.thanks for clue. U4901 give 3v on pin 28 socket lcd right. But how if u4901 culprit? Any equivalent fet i can replace?

[JaroTech]

Re: Acer aspire 4752 white screen

No, U4901 will give you 3v on the pins 29 and 30, the power to the lcd.

[sasser]

Re: Acer aspire 4752 white screen

Here an update. After measure all pin below

Pin 28 at lcd socket cable 3.3v

Checked u4901

Pin 1 3.45v
Pin 2 0.0v
Pin3 0.224v
Pin 4 3.3v
Pin 5 3.3v

[sasser]

Re: Acer aspire 4752 white screen

I measured again like jaro suggest and i found pin 29 and pin 30 only 0.22v seem no volt here .

[sasser]

Re: Acer aspire 4752 white screen

Thanks jaro. This problem solved

[JaroTech]

Re: Acer aspire 4752 white screen

Remove U4901 and short momentary the pins 28 and 29, you should have a picture on the screen, that means the U4901 is defective.

[dj_ricoh]

Re: Acer aspire 4752 white screen

Thanks jaro. This problem solved

how?

[sasser]

Re: Acer aspire 4752 white screen

how?

replace new u4901 friends