Asus X51RL Motherboard Repair

[GazzaS]

Hi,

New to this forum so hi all.

Basically our family laptop (Asus x51rl) died a death due to a faulty power supply. I could smell burnt silicon from inside it and dismantled it to find the issue.

I've found the source of the issue which is a burnt component by the battery socket which must be some sort of shorting pin. I've fixed computers all my working life and build electronics for a hobby but have never had a go at fixing integrated circuits before. Hell, what have I got to lose

Can anyone identify the component that is burnt out, I've attached two images of the damaged board and a couple of images I found on the net of the same board area with no damage.

Thanks for any advice,

Gary

 

[mindless1]

Looks like it might be a transistor, though picking a replacement would be easier if you can get a part # off of it from another board.

 

[GazzaS]

Hi,

Thanks for your reply.

After a lot of searching (mainly non-english sites with google translate) I have found a few more images:

According to the forums it is a 5 volt Regulator part of the 5 volt stabilizer circuit labelled PU5900. The actual chip has marking 8C752 and they call the chip Stabilizator (but this could be a bad translation). They also mentioned replacing it with L78L05ACUTR.

Does this seem right from the new images? Would replacing the chip with the L78L05ACUTR be ok?

Thanks again,

Gary

 

[PhIlLy ChEeSe]

Unless your a bench technician, which yer not your throwing dead money at dead money. Replacing that part is not going to fix this, I hate to tell you.
Even if you do replace the part in the picture, it was caused by something else that made it happen(like all the dust in side of it). Unless you fix the CAUSE, fixing a residual effect will NOT FIX THE ISSUE....................

 

[mindless1]

Considering the low cost of a L78**** it seems worth a try to replace it. Philly Cheese may be right that it's an effect of more damage, but for now all you can do is replace what you know is bad and hope for the best.

 

[GazzaS]

Picked up the chip for $2 so probably worth just giving it a go. I have all the bench technician equipment from my Robotics days.

PhIlLy ChEeSe - I believe the cause was a faulty power supply. Looks like the wife pulled it out to hard and shorted the wires, then tried plugging back in. Bang! I've also purchased a replacement battery and power supply for $30.

I've gone through the rest of the circuit board and cannot see any other damage.

Thanks for the advice.

Gary