Good day all.

Ive received a Compaq CQ40 laptop wich powers on , no video and has the usual blinks on the caps led , but applying a mild pressure on the cpu does bring the machine to post.

So I wonder if anyone has experienced a CPU socket becoming loose , I read somewhere else that reflowing might solve such issues but ive never done a reflow to a socket , anybody succesfully tried it? if so what technique did you use?

Thanks in advance
Aiki

Do not rush to change the socket CPU. The problem may be in the north and in the processor. To beginning you need to change the processor. How many flashes Caps led?

If a socket, it must respond to pressing. Hold it and turn on the laptop.

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Ohh believe me , im not rushing at all wasnt even sure you could even replace it , but ive tested this motheboard bare with only verified cpu and memory modules to no avail.



Thats what I did , installed tested cpu and memory and turned on while applying a slight pressure over the cpu (with the heatsink installed) , it managed to pass the power on self test (POST) and bring up the compaq logo , i switched off quickly to avoid further damage.

So im quite sure its the cpu socket , question is , what now?!

Its possible to fix or even replace it with just a SMD rework station? (Aoyue 968)

Thanks both for your time.

I don't think 968 will provide sufficient heat to resolder the cpu socket. Maybe preheating the whole motherboard slowly until it reaches 240ºC and carefully heating the socket in a circular motion may help. Do not apply heat from the hot air station over the plastic, it will probably damage it.

Hey Ablacon64

Yes , somehow melting or damaging the plastic of the socket if my chief concern. You mention not appling heat directly to the plastic but also to use a circular motion , so where should i direct the heat , the other side of the board under the socket? also , wich position should be the socket in to try the reflow locked or unlocked? , I assume it should be locked as that is the position in wich the CPU works.

Your insights are very helpful people , thanks.

[img]yoeyat.com/images/2011-06-29%2017.18.54.jpg[/img]

use bga rework instead. can control degree in 245C.

Preheat (and keep the heat during the process) the board until it reaches 240ºC (from below), direct the heat "around" the CPU socket (set 968 to 370ºC or so).

I keep the socket locked but it doesn't really matter because the solder spheres do not change. It helps if you can protect the socket using good quality kapton tape.

Well I've followed ablacon advice and tried the reflow on the socket and the lappy manages to boot and load the OS but only while dissasembled and blue screens after running a few mins , So I'm putting away this patient until I get a hold of the proper tools (BGA station).

Thanks all.

Better decision. :)
That way you avoid damaging the cpu socket.

Maybe Bios Problem. Need to reflash bios.