Help me with laptop diagnosis

JRDtechnet

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Well someone brought a laptop to me with a suspect DC Jack (won't charge the battery and doesn't power up without the battery in the machine) I just took it apart and the dc jack is perfectly fine and I get continuity to different parts of the board both on the ground and hot. Now this laptop happens to be identical to my laptop so I stuck my charged battery on it and it boots up. If its not the DC jack what else can it be?
EDIT: I should mention I tried his adapter and my adapter (they are identical) so its not a bad ac adapter either.
 
sounds like the motherboard where the dc jack fits on... I know on the dells, you have to replace the motherboard if this happens. Computer works... but battery will never charge.
 
No those dells your talking about have a center pin that detects the power brick. This is a normal plain old DC jack. The Dell problem also would still let you power the laptop with the ac adapter plugged in.
 
Could the battery just be boned? It's possible that the battery has to be in place (and functional) for the DC power to work.... just a guess. Possibly why it works with your battery in place. Try his battery in your laptop, with your power supply and see if it works. If it doesn't I'd say the battery it toast.

Good luck...
 
I had the same problem with my wifes dell laptop. Apparently Dell power jacks are notorious for going bad. I ordered a new power jack from e-bay, soldered it in and it worked perfectly.

Her laptop wouldn't work with the battery (it was dead because it wouldn't charge) and it would only work with AC power if I put alot of pressure on the jack and held it.
 
I have seen these symptoms caused by a bad battery. With some laptops, if the battery is completely screwed, it won't turn on even when plugged in. Since you have another battery there, I think it should be easy to test.
 
So you have your diagnosis, the mainboard is Fubar'd. Offer a rough but realistic estimate on mainboard replacement and give an alternative of copying his data onto a new machine plus charge for diagnosis of his old machine.

Don't waste your time trying to repair something that's beyond economical repair - it's not viable for your business or your customer's.
 
Do you get voltage to the battery terminals? I would also say the mobo is bad, there's probably a bad circuit somewhere, very hard to diagnose with simple tools we often have.

I would check to see how much voltage is getting to the battery terminals and compare it with your working laptop, should be identical voltages, if you see a difference then you know have your answer, bad mobo!!
 
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