Hello,
Managed to buy a defective board from eBay. Board is okay, but no video on internal screen, but on HDMI. With this board I can test all the voltages and maybe find the fault of my board.
Regards,
Constantin
The defective board arrived yesterday and works expect of the internal screen. I measured some voltages and found out, that the screen isn't recognized by the board at all...webcam works btw.
I also found out, that Panel VCC of J4502 is not available
Voltage on both sides is 0v, but the board is Rev. 2.0 and not 3.1 - when I look at the boardview of Rev. 3.1, there are two resistors in this area, on my board are only two of them.
U4501 is the main suspect now. but you cannot be sure unless you mention voltage on all pins of it. take a lot of care not to shorten it's pins when measuring. Es ist wirklich riskant zu messen.
If the laptop shows picture on the VGA and the HDMI ports, then U4501 is probably faulty. In another case, it is also possible that the CPU or GPU be faulty. Is there any GPU on the mainboard?
finding the datasheet of ANX1121 would help, but it seems it is not available. I found just a single page datasheet for it which is not useful to us.
If the laptop shows picture on the VGA and the HDMI ports, then U4501 is probably faulty. In another case, it is also possible that the CPU or GPU be faulty. Is there any GPU on the mainboard?
finding the datasheet of ANX1121 would help, but it seems it is not available. I found just a single page datasheet for it which is not useful to us.
Okay
GPU is an NVIDIA GeForce 820m
Maybe tomorrow I will manage to solder the N Channel mosfet to the other board, to make it power up again. Maybe then the laptop works again.
I tried to solder the part, but I think I didn't suceed, no voltage after the part. Maybe the soldering is bad - can you tell me a good flux?
We also found out that on the board which powers up we has around 6v on PIN 12 of PU 9100. In the datasheet this pin is called SS1 (soft start 1). Does the IC get a voltage from here or does it produce this voltage by itself?
If the voltage Comes from outside, the Problem is another one.
Well, then the soldering job was shit. The solder didn‘t even melt, so I guess that is the problem.
Tomorrow I try to take the solderiron down and put new one on the pads.
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