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Replacing A5sHB transistor (netbook)

dorke

Jun 20, 2015
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Fully charged battery measures 4,12v on its terminals.

Pink-line doesn't measure anything.

Green-line measures 4,12v on all its traces.
O.k
I'm re-posting from #7:

Please post two separate and clear(so that the device markings are readable) photos of the two squared areas in green and pink.

Transistor 2.jpg
 

dorke

Jun 20, 2015
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This is hard to follow.
are you getting a 5v on the usb port?
what do you measure on Q4 pins?
What voltage do you get between pins 8 and 4 of the 25x40 -windbond IC,
(near the VIA IC)?

In the top photo you have a bunch of dc-dc converters that should create the different dc voltages for the netbook.

I think you should operate the netbook with the battery alone and measure voltages from it's positive terminal to the devices it is getting to then measure the voltages you get on that device and continue tracing it to the next one.
Maybe this way we can find something.
 

Paligap

Feb 23, 2016
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I only get the 4,12 on the USB when I measure from the + pin of the battery, I get those 0,22v on the USB when I measure on GND and the + pin of the USB.

Don't measure anything on the IC, same case as the USB.
 

dorke

Jun 20, 2015
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Please,measure the voltages on the 4 green arrows on the photo.
Only with battery connected(no adapter)
All measurements should be related to GND.

Board 1.jpg
 

Paligap

Feb 23, 2016
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Diode: 4,12v on its left pin (near the S) and 0,40v on its right pin.

The pins you marked on the Q show nothing but 0,2v.
 

dorke

Jun 20, 2015
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Please mark the direction(cathode line) of D14 on the photo.
 

dorke

Jun 20, 2015
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Please measure the yellow arrows and mark the other ss24 diodes.
Board 1.jpg
 

dorke

Jun 20, 2015
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1. The 0.2v on the cathode of D1 is suspicious.
looks like it goes to the other side of the board through those 6 vias ,can you trace that connection.
2. Try to trace the 4.12V from the 000 ohm resistor.
Board 1.jpg

3. Taking another look on the other side of the board ,
I see what may be test points for voltages,
many of them I just marked a few.
can you confirm and if so measure voltages on them.
Board 2.jpg
 

Paligap

Feb 23, 2016
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The Diode goes to those two resistor and the capacitor, on the other side of the board.

4,12v on that v. point, the rest don't measure anything.

I'll post the trace of the 000 resistor in few min.

Board PART B.jpg
 
Last edited:

dorke

Jun 20, 2015
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The Diode goes to those two resistor and the capacitor, on the other side of the board.

4,12v on that v. point, the rest don't measure anything.

I'll post the trace of the 000 resistor in few min.

View attachment 25546
Please,a clear photo of the area with the white trace .
 

Paligap

Feb 23, 2016
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I apologize, my bad, it'd be like this:

BOARD 1 DIODE.jpg


The only Diode that measures at both sides is the D4, but it may be that it has that other little D beneath him.

Picture of the other side of the board related to the Diode:

Sin título.jpg
 
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