Short on ASUS Laptop

[hephaistos]

Re: Short on ASUS Laptop

try replacing the md chip.

Excuse me but i don`t understand what md chip is.... are you refering at that MB39A132?
One other thing: if the chip`s only task is to take care about the battery i think the laptop should have started and not charge the battery but mine doesn`t start at all. Does this chip do other things too?

Thanks!

[fpaliuc]

Re: Short on ASUS Laptop

I have the same problem due to inverted polarity on the power adapter. The MB39A132 IC has the burned sign. Also, I've checked the 4835GM SOP8 IC Chip (the upper right one) and all the S-D pairs are shorted. The diode is OK.

When I connect the power adaptor, there are sparks comming from the connector and the PC doesn't start. Would I solve the issue only by removing the bad MB39A132 IC and only soldering a new 4835 IC? (I don't care about the battery not charging. I only need the PC to work while powered from the AC source).

[londoner]

Re: Short on ASUS Laptop

Hope this thread is still being followed!

My daughter's laptop won't charge using the external PSU, so I took the mobo out and can see a part that is burned out, but I can't locate it on what I think is the circuit diagram (got from the post above - thanks!)
I've joined the two together below.
Assuming this is the correct section of the schematic (my mobo is rev 2.1 but looks identical) - the underside of the board gives no clue as to how the components are connected together.

Anyone know what the burnt-out component was?

[khaahk]

Re: Short on ASUS Laptop

It is D6801 protection diode against reverse polarity. You can remove it and test run without it to see if anything else has burnt.

[londoner]

Re: Short on ASUS Laptop

Thanks!

Didnt get a "thread changed" email or would have replied sooner.

Cannot find the part by googling - is it in this class:
http://cpc.farnell.com/transient-voltage-suppressors

If so, will this one do it?
http://cpc.farnell.com/fairchild-sem...smc/dp/SC07237

Also, can I just plug the bare mobo into the DC power by attaching the plug? I had to remove the CPU heatsink to get it out to trace the fault. I presume if you power a "bare" mobo like this, thermal protection will prevent CPU damage?

Thanks again - really appreciate it.
Chris

[khaahk]

Re: Short on ASUS Laptop

You can remove the diode and test the mainboard even without CPU, it should still charge or show charging light. There is a good possibility that something else has gone bad also. Then it would be a waste of time and money to replace the diode.
If test run is ok then look here:
Ebay - in UK:
http://www.ebay.com/itm/SS0540-SMT-M...item5aea91b1e0

The SC07237 should be ok also but might be bit big to physically fit.

[vienzen]

Re: Short on ASUS Laptop

Hello there did you solve your problem?