HP G62 No dispay, to external screen OK

[s_henya]

Hi Guys,

Found this laptop on it's way to the trash.

HP G62-460SJ

mainboard: 634649-001

It boots but shows no picture.

I connected it to an external display and it works good.

I tried taking it apart and reconnect everything once more but got the same result.

I tried replacing the screen with a busted one i replaced not long ago and know that it should show at least backlight.

I reflashed the bios to F.37 but it already had that version- it did reflash but changed nothing.

So i have 2 possibilities: the lvds cable from the mainboard to the screen is faulty or the mainboard is bad.

Any tips before i order a board from Aliexpress?

[Djosla]

Re: HP G62 No dispay, to external screen OK

I belive that model has switchable graphics so you should reball nb chipset (not gpu)...known fault with that model...

[s_henya]

Re: HP G62 No dispay, to external screen OK

Unfortunatly all i have is dual soldering iron/hot air.

I don't don't have any reballing equipment.

[cyberhack]

Re: HP G62 No dispay, to external screen OK

Before you trash it, cook it for a quick test

[s_henya]

Re: HP G62 No dispay, to external screen OK

i will try to reflow.

which chip to reflow?

what is the recommended temp(C)? for how long?

[cyberhack]

Re: HP G62 No dispay, to external screen OK

A good read

[rs232killer]

Re: HP G62 No dispay, to external screen OK

if its ok in external, maybe a different path would be a good idea,
lvds cable
lcd

is the lcd dark only, img but no light ?

regards
RS

[Djosla]

Re: HP G62 No dispay, to external screen OK

if its ok in external, maybe a different path would be a good idea,
lvds cable
lcd

is the lcd dark only, img but no light ?

regards
RS

yes you should check this first...Also check lvds circuit (lcd vdd,lcd en,bcklt en,etc... )
Well if you dont have proper equipment you can try reflowing with hot air but hmmmm it won`t be good...
I thought it`s different board ...
If your board is like the one on the picture you posted then try reflowing gpu chip next to the CPU (first bga chip on the left side from cpu...upper one is pch chip)

[samanthban]

Re: HP G62 No dispay, to external screen OK

if you have osc check for O+ 0-1+1-..

[ala_borbe]

Re: HP G62 No dispay, to external screen OK

if its green board like in a pic try removing PU320. thay should disable ati vga completly and use only intel on cpu vga (uma)

i did that on my G62 with board DA0AX1MB6F0 and now it works

[s_henya]

Re: HP G62 No dispay, to external screen OK

thanks guys for all the tips!

i will first try to order a new lvds cable.

if it won't work i will try to take out PU320 if that wont help i will try to reflow.

[s_henya]

Re: HP G62 No dispay, to external screen OK

yes you should check this first...Also check lvds circuit (lcd vdd,lcd en,bcklt en,etc... )
Well if you dont have proper equipment you can try reflowing with hot air but hmmmm it won`t be good...
I thought it`s different board ...
If your board is like the one on the picture you posted then try reflowing gpu chip next to the CPU (first bga chip on the left side from cpu...upper one is pch chip)

Sucess!

The LVDS cable arrived today from china, i tested it but got the same simptom.

I had nothing to loose so i decided to reflow the NVIDIA gpu.

250 degrees celsios for 3 min.

And i got perfect picture.

thank you all for the help.