compaq cq41 dead

[lcrcron]

hi all, I have a compaq cq41 dead, no indicator when power on, led indicator when power adapter plugged also dead.
anyone have a solution

[gabik111]

Re: compaq cq41 dead

Did you check power supply? It may be a power jack or power supply.

[mattbrad2]

Re: compaq cq41 dead

So you've verified the charger is working properly? Does the charger short or go into protection mode when plugged in to the laptop?

EDIT: looks like gabik111 beat me to it.

[lcrcron]

Re: compaq cq41 dead

charger works fine on another laptop and the battery works fine too

[kaboom]

Re: compaq cq41 dead

If the DC jack is on its own little PCB, check the jumpers from it to the motherboard for breaks/bad solder. Check power MOSFETs for shorts.

I had a Samsung 42" LCD TV where the backlight failed. The backlight enable pin to the inverter never was soldered! Just the bare copper via... the terminal's pin loose in it. A friend got it from craigslist cheap, and a little solder later, it was fine.

-Paul

[gabik111]

Re: compaq cq41 dead

So if the battery works you'll need a schematic a remove laptop apart. Then study on diagram and closer look on mobo. Looks like kaboom is right about power transistors on charging/power distribution section.

[nish_pinto]

Re: compaq cq41 dead

How to check if mosfets are short?

[sasser]

Re: compaq cq41 dead

i also had the problem no power compaq CQ41. no light at DC jack light indicator. check power jack got 18.5 its correct. but no power to board and cpu. vccore no value. anyone hav the schematic diagram of compaq cq41? what mosfet hav to check and where to

[opamp]

Re: compaq cq41 dead

Actually vcc core voltage will not be present by just plugging in the ac adapter. You should check for 3 and 5 volts Always on first. 3.3 volts should be present on the power button at all times.

[sasser]

Re: compaq cq41 dead

oh ok. vccore no present value when pluggin ac adapter and i check power button got 3 volt. what u means "You should check for 3 and 5 volts Always on first" where to check

[opamp]

Re: compaq cq41 dead

There's a voltage regulator that produces 3 and 5 volts when you connect the power adapter. It's called always on because it should be present without pressing power button. Try and find the schematic so you will have a better understanding how power is distributed. More than likely you have a shorted component. Check mosfets and capacitors out of circuit.

[siddiq]

Re: compaq cq41 dead

oh ok. vccore no present value when pluggin ac adapter and i check power button got 3 volt. what u means "You should check for 3 and 5 volts Always on first" where to check

Do you have the schematic? So we can proceed from there.

[sasser]

Re: compaq cq41 dead

i dont hav shcematic diagram. already replace ati bga but still no display.that the others thing must chech to determine the gpu is ok or not. some value present at the capacitor below cpu pads?

[survey]

Re: compaq cq41 dead

I have two schematics for this laptop, both from COMPAL: la-4106p and la-4107p

[madank]

Re: compaq cq41 dead

I have two schematics for this laptop, both from COMPAL: la-4106p and la-4107p

thanks 4 schematic