820-00138 dont turn on

Dozer

Member
I have this device here, no green/orange light, dont turn on.

found short R7121 Pin 1 to ground and high resistant R7121 and R7122

after replacing u7100 there was no short anymore.

So i replaced the R7121 and R7122 after that all was ok but i found there goes 6A in to the machine.

So I replaced both R7121/2 again. After that the current in to the machine didnt rise over 3.6A

So I thought everything fine, gave it back the client. machine came in today with the same problem.


So i replaced u7100 and R7121/2, after that again no short but on mac safe no green/orange light, machine working good.

So I still replaced the DC-in conector. After that I got green/orange light. current in to the machine again until 3.6A

So I still have any idea what can be here the problem. I think, if I will give it back to the client it will break again.

Is it possible that the dc-in still was broken and that was the main reason?

is 20V on the laboratory-unit correct for A1398 2015 ?
 
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Dozer

Member
is it possible that the dc-in was the problem ?

yes, i have a original charger, will try that, had only the lab-unit tryed
 

Dozer

Member
I tryed with my original charger , no problems.
my client told me he have a good original one too, here a pic.

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can u imagine that it could be possible a bad dc in board?
 

Dozer

Member
is it possible that there could be from the beginning the main problem a bad dc-in board?
can to much current caused by a bad dc-in board damage the u7100 and r7121/2 ?
 
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