Re: dell N5010 BIOS
Thank you so much to all of you who posted these files. Very helpfull.
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Hi sorry im looking for the schematic of a 6-71-m1100-d02a gp
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Re: LA7401P Short to ground
So I assume that there is a problem in the 1.5V power rail on the board side. what is your thought about this? Thank you for your responses
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Re: LA7401P Short to ground
Hi Caspian. I tried to remove the inductor, PL401 these are the measurement I got:
PQ401
pin 1 to 3 = 1.70v (before pressing the button) 3.56v (after pressing the button)
pin 4 = 4.26v (Before and after pressing the buttonn)
pin 5 to 8= 18.7v
PQ402
pin 1 to 3 = 0.01v (before pressing the button) 0.03v (after pressing the button)
pin 4 = 0.03v (Before and after pressing the buttonn)
pin 5 to 8 = 1.70v (before pressing the button) 3.56v (after pressing the button)
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Re: LA7401P Short to ground
Could you please quickly explain to me how this 1.5 circuit works (Pq401, Pq402 and the PU401 that controls the mosfet?
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Re: LA7401P Short to ground
5V alw and 3V alw are present before pressing the button, what other power rail can I check?
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Re: LA7401P Short to ground
Cool, PU401, pin 1
before pressing the button= 0.01
After pressing the button = 0.03
what does this mean?
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Re: LA7401P Short to ground
Hi there
Pq401 Voltage:
pin 1 to 3 = 0.02v
pin 4 = 4.39 v
pin 5 to 8= 18.99v
Pq402 Voltage:
pin 1 to 3 = 0.0
pin 4 = 0v
pin 5 to 8 = 0.02
ps: both Mosfets are off the board. I am only testing the pads.
thank you for your assistance
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Re: LA7401P Short to ground
pin4 of pu401 = 4.38V before pressing the button and pressing the button it stays the same, 4.38V.
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Re: LA7401P Short to ground
ok.
pq401
pin 1 to 3 = 391 ohm
pin 4 = displays 1700 ohm then meter goes to 1
pin6 to 8 = displays 1700 ohm then meter goes to 1
pq402
pin 1 to 3 = 008ohm
pin 4 = 1415 ohm
pin6 to 8 =225 ohm
ps: I put the negative prove on the ground and the positive probe on pins to test. is that okay?
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Re: LA7401P Short to ground
Must I put back PQ402 on the board? because I removed both pq401 and pq402
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LA7401P Short to ground
Hi there.
I have a LG laptop that was completely off. I open and check on the board, there was 2 burnt mosfets (PQ401 and PQ402). I removed them from the board and tried to plug the laptop, the laptop switches on and goes off after a few seconds. Now I replaced both mosfets, the laptop don't switch on and PQ401 is overheating(very hot). Where can I test and how can I resolve this issue? Any help is much appreciated. I have attached the schematics and a pic of the affected area....Last edited by alfasys; 07-20-2017, 09:04 AM.
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Re: VAR00 LA-9201P short to ground
Hi there.
I just read Caspian posts, they are really helpful. I also have a motherboard that is short to ground. they were 2 damaged mosfets that I replaced (PQ401 and PQ402). when I plug the laptop, PQ401 get very hot (burning) and dies. I replace it 3 times, it does the same. Whe can I take the measurement and how can I proceed? Please help....Last edited by alfasys; 07-20-2017, 08:35 AM.
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