As per the title, I am trying to repair a friends Acer Aspire One ZG5 netbook that got itself between him and his crazy, now ex, girlfriend during a domestic.

I have replaced the plastic bits and screen but now it wont boot at all. after getting my microscope out I found the problem.

The daughter board was subjected to quite a bit of lateral force and one of the diodes in the power switch chain has snapped its moorings. This has of course resulted in a non-responsive machine.

The problem I have is I cannot find any data on this diode (Nj JA8) Surface mounted. I cannot be certain of the Nj bit because the j is not very clear.

Any ideas about what diode I should replace it with? There is plenty of space to replace it with a non-surface mount diode so that's what I will have to do. I just don't want to fit one that would be bad for the rest of the circuit.

Thanks

Larry

 

marking on many, specially SMT components, often does not resemble part number. if you are certain it is a diode, there is not much too choose from as it can be either rectifier (standard or Schottky) or
zener.

in comparison with standard rectifier Schottky has lower forward voltage (also reverse voltage).

if it is zener, it would be reverse biased and if disconnected chances are you would still have unit power up (unregulated, higher voltage).

to tell more one would need to check the circuit and determine.... any pics?

 

Well, yes I get what your saying. unsurprisingly I don't have much experience with SMT components. It looks like a normal through hole diode except rectangular, black plastic with a grey strip on one end with a connection on the two ends.

Having looked just now, at the wiki page on SMT components. I now realise that it is in fact a capacitor. Which I now also realise would be why I could not find a diode of the necessary type or size on the circuit diagram and also why there is no component ID anywhere near the component in question starting with a D only C's.

If you had not questioned the possibility, I probably would not also have questioned it. So thanks for guiding me in the correct direction.

Having thought about it I decided to have a look for a replacement daughter board. Luckily they are only a couple of £ so I ordered one.

Now knowing what it is I can fix it and possibly sell it on later.

Thanks for your insight.

Larry

 

good luck with it