compaq cq61 not working

[azza1234]

Hi ive got 2 cq61 laptops but only one screen which im having trouble with both of the mother boards one when plugged in just has a white screen and the other when the screens plugged in works but has no backlight am i right in thinking that i need a new inverter?

[azza1234]

Re: compaq cq61 not working

Hi ive got 2 cq61 laptops but only one screen which im having trouble with both of the mother boards one when plugged in just has a white screen and the other when the screens plugged in works but has no backlight am i right in thinking that i need a new inverter?

Forgot to mention they both work fine on external screen

[lord]

Re: compaq cq61 not working

I saw it is a backlight problem. Measure voltage on all pins on the input connector of the inverter

[dj_ricoh]

Re: compaq cq61 not working

Hi ive got 2 cq61 laptops but only one screen which im having trouble with both of the mother boards one when plugged in just has a white screen and the other when the screens plugged in works but has no backlight am i right in thinking that i need a new inverter?

the white screen its bad?
did you switch them ? white one without backlight?

[azza1234]

Re: compaq cq61 not working

the white screen its bad?
did you switch them ? white one without backlight?

Hi tried the screen on both laptops one there is a picture but no backlight and the other one the backlights on all the time but no picture just white

[trebo]

Re: compaq cq61 not working

try swapping the inverters, that should give you backlight on the one that displays

[azza1234]

Re: compaq cq61 not working

try swapping the inverters, that should give you backlight on the one that displays

Ive tried that and still does the same with picture but no backlight ive even swapped the lcd cable but still the same

[sanehdeep2012]

Re: compaq cq61 not working

I Think you have AMD or nvidia version of CQ61 try to reball the north bridge or GPU chip

in most cases reball solve the problem

[Life Goes On]

Re: compaq cq61 not working

If the screens plus the inverter are ok, then reball the gpu,
i don't think the north brige, cuz it work on extern.

[azza1234]

Re: compaq cq61 not working

Hi my friend reballed both of the motherboards and still have no backlight through motherboards I used in car dvd screen inverter and the screen lights up so its not the backlight bulb so im quite stuck is there a circuit on the motherboard that powers the inverter? I get 18v on inverter plug

[loser18]

Re: compaq cq61 not working

What's the mobo number?

[azza1234]

Re: compaq cq61 not working

Where would I find this?

[loser18]

Re: compaq cq61 not working

on mobo itself...I reckon it's quanta so it should look like DA0xxxxxxxx...

[azza1234]

Re: compaq cq61 not working

It is DA00P8MB6D0

[loser18]

Re: compaq cq61 not working

There's schematic...
What's the behaviour of both boards after reball???
Still the same?

[azza1234]

Re: compaq cq61 not working

Thankyou the one that the backlight wasn't working on but had a faint image is still the same (faint image no backlight) and the other one just stays on a black screen now instead of just a white screen

[loser18]

Re: compaq cq61 not working

And both working fine on external?if so what port HDMI or CRT?

[azza1234]

Re: compaq cq61 not working

Yer both work fine on external with hdmi cant find my vga cable to test vga thou

[loser18]

Re: compaq cq61 not working

OK...Could you post mesurements of all pins of LVDS connector (CN1)...

[azza1234]

Re: compaq cq61 not working

Right I tried to measure voltages on cn1 and managed to blow up the mother board lol so have to try and fix the other one (one with picture no backlight) on the inverter the voltages are as follows
1-18.64v
2-0.0v
3-3.26v
4-0.0v

Im sure pin 4 is ground and pin 1 is the right voltage but what should 2 and 3 be?