Re: Medion MD42200 does not power up
today I desoldered the MOSFET and the diode test showed in one direction an infinity and the other direction 536.
Where could I also look for a defective component on the board?
KG21
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Last Activity: 12-15-2016, 11:07 AM
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Re: Medion MD42200 does not power up
I lifted the pins 1 to 4. So three sources and the gate and one drain (pin 7) is lifted. If I check the MOSFET now, my mutlimeter will show me a 478 and 1041. There is no infinity.
I also made a mistake at the first pin. The leg did not break but it is not attached to the MOSFET anymore. Now I can really purchase a new one.
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Re: Medion MD42200 does not power up
Well, I lifted at the Mosfet U27 one drain and one source leg. That was the 2pin/2pin. The results are the same like before.
diode test again with Multi Meter:
2pin <-> 2pin: 407 reverse: 186
3pin <-> 3pin: 407 reverse: 186
So the Mosfet AO4406 is defective, because it does not have an infinity, right?
I also lifted C198 and it is as you said. Both capacitors showed in the continuity test that the resistance increases and finally the multi meter showed an infinit...Leave a comment:
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Re: Medion MD42200 does not power up
It sounds like the videoclip test capacitors from prehertech that I watched on youtube yesterday
Maybe I could use my hot air gun to lift U27 and one capacitor from the board? The solder should melt at around 180°C, I guess.
I hope I can find then the cause of the problem....Leave a comment:
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Re: Medion MD42200 does not power up
thx b700029. it was really a "5" not an "S".
I could not wait until friday so I already have checked the board.
Firstly, I made a mistake with the red circled components. The real numbers are for U26: AO4422 BD4K23
and for U27: AO4406 BD313V.
I've got the following voltages for U26:
Source (pin 1 to 3): 2.7V
Gate (pin 4): 3.52V
Drain (pin 5 to 8): 18.63V --> the AC Adapter delivers ca. 19V
diode test with Multi Meter:
...Leave a comment:
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Re: Medion MD42200 does not power up
the right circled components are: AO4407. the company is alpha & omega. I found it. But the APL component is still left.Leave a comment:
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Re: Medion MD42200 does not power up
thank you for your answer mattbrad2.
I will check it on friday and yes I have a digital volt meter. I tried to get the datasheets for the three components but didn't find anything.
Here are the part numbers:
left component circled: APL S331 BG7CH --> could be a dual channel because of the "CH"?
right components circled: should be both 4407 BE4S13 and have a symbol on it is something with an "A"
I tried to find those components at alldatasheets.com but without success....Leave a comment:
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Re: Medion MD42200 does not power up
Here I made two pics of my board:
the second photo shows red circled 8 pin chips. I don't know if they are MOSFETs. But they have a temperature over 50°C right after I plugged in the ac adapter and the videochip gets hot, too. Could they be defective?
Also the power LED lights up if I plug in the ac adapter and then the Laptop turns off themselves, all without pressing the power button. This isn't normal.
...
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Re: Medion MD42200 does not power up
I have done that. But no success.
I'm not very good at electronics. If the board would have a bad video card, I had made a reflow and done. I found a board on ebay but I don't want to pay 50 euros for it.
I looked in the sample schematics that I have and I think my motherboard is a little bit equivalent to the schematics one. It uses almost the same Max ICs. Maybe I find the way of the power to the defect.
I asked in my first post whether I can use the my universal adapter...Leave a comment:
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Re: Medion MD42200 does not power up
I looked it up and the result was that the Medion MD95101 has the same motherboard in his system.
On the motherboard is written:
HannStarJMV-4 94V-0
0436632
MD1 M/B
48.46P01.011
I know Hannstar makes also Mainboards for Acer, Gateway, Mitac etc. But if I google the part nr. 48.46P01.011 with gateway with gateway or mitac I don't get an equivalent motherboard as result.
Is there another possibility to do something?Leave a comment:
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Medion MD42200 does not power up
Hello badcaps members,
I hope you can help me. I have a Medion MD42200 motherboard in front of me and it does not power up neither with ac adapter nor battery.
If I press the power button on the laptop the power led lights up just for a half second, the fan always doesn't turn on and then the laptop powers off.
I checked the AC Adapter and the DC In Jack of the laptop and both are ok.
I read to check for bad capacitors or hot mosfets I should use a variable power supply with 1.5V/1A, but I only have a universal ac adapter with the lowest voltage of 12V... -
Re: New Members - please post your introductions here
heyho, i'm also a new member of this great forum
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