Need some help here guys. PQ11 source and gate voltages is OK 18.8v but 0.47v on drain which is coming from PQ9's source, gate is 19.2v. Already replaced both Fets.
Thanks.
Thanks.
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Re: LA-3541P No power
Gate should be low. That's a P-Channel mosfet. It is locked in protected mode. Check 19V line for short and if charger is faulty.Last edited by atsio; 03-24-2014, 09:36 AM. -
Re: LA-3541P No power
If you don't have any short on 19v line and charger measures ok, just strap that MOSFET and call it a day.
I've seen this issue on multiple boards and it's a royal pain tracing the drive of that fet. I broke a board while tracing such an issue when a wire slipped and shorted the CPU VRM, and ever since i haven't bothered to trace that ever again. This usually happens after a charger with higher voltage is accidentally used with the laptop, and if there are no shorts on any of the power rails, simply jumping that FET will work fine.
Of course, with that MOSFET bypassed, all bets are off if 24V or something silly is applied again, but that's the user's problem, not yours...
A working TV? How boring!Originally posted by PeteS in CAComment
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Re: LA-3541P No power
what do you get at pin 2 and 3 of PU1A? If pin 1 of PU1A is low you will get 19v at the gate of PQ11.Comment
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Re: LA-3541P No power
Thanks a lot guys for the answers.
PU1
pin1 3.19v
pin2 3.33v
pin3 3.67vComment
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Re: LA-3541P No power
On those boards, its very common to have a capacitor failure. Chek all capacitors for shorts, you can pull out the inductors Pl4 PL14 PL9 Pl17, so you can localize shorts.Comment
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