Mini pc board no charging, no lights.

[Cryogen]

Hi

I have this mini pc board who refuses to charge and it is completely dead. No charging light would come on when plugged in.

The battery shows 11.95v from the 11.85v nominal


There are 4 mosfet (2 front and 2 back of the board) near the battery connector. only one gives 11.95v readings the other 3 show 0v.

Is the one reading 11.95v shorted? Or the one showing 0v next to the 11.95v readings that it is the culprit?

edit: the one with voltage is showing a short on gate, drain and source as well.

Thanks

[Cryogen]

Re: Mini pc board no charging, no lights.

Removed the mosfet and it still gives me continuity on the pads. All the caps that are not receiving current from the mosfet I removed are giving me a short on the multimiter.

[SMDFlea]

Re: Mini pc board no charging, no lights.

Hi

I have this mini pc board

Does this "Mini pc board" have a make and model number.We would like both in the thread title and also the description,and whats the motherboard part number ? .If a schematic isn`t available it would be nice to have some pictures of the motherboard.

.

[Cryogen]

Re: Mini pc board no charging, no lights.

Does this "Mini pc board" have a make and model number.We would like both in the thread title and also the description,and whats the motherboard part number ? .If a schematic isn`t available it would be nice to have some pictures of the motherboard.

.

Hi

Pics.

You can see in the second pic I have removed the mosfet giving me 11.9 volts. I think the culprit might be the other one since I can only find 11.9v from the drain of the one I removed to the gate of the one I left on.

[Cryogen]

Re: Mini pc board no charging, no lights.

I found 2 blown/cracked esd diodes as well

"5b" marked. Anyone could give me hint where to get them (alternatives welcomed). Don't want to jump them.

Thanks

[mon2]

Re: Mini pc board no charging, no lights.

Never jump the parts unless more is known about their function (i.e. 0 ohm resistor = short).

Can you post a clear pic of the part?

[Cryogen]

Re: Mini pc board no charging, no lights.

Never jump the parts unless more is known about their function (i.e. 0 ohm resistor = short).

Can you post a clear pic of the part?

Hi
Pic. Does b stands for bidirectional? Cause it looks like a bi zener.

[Cryogen]

Re: Mini pc board no charging, no lights.

Anyone?

A help with the rating of those 2 diodes?

[SMDFlea]

Re: Mini pc board no charging, no lights.

Anyone?

A help with the rating of those 2 diodes?

Is it a laptop or a PC ? .If its a PC i will move the thread from the laptop forum to the PC forum.We do ask questions for a reason,it would be nice if you could answer the questions asked at post #3.
Also,now that you`ve posted pictures of the diodes,if thats what they are, we can see that they are not marked 5b but are 5B ,it makes a lot of difference when trying to track down the part.It has the letters LC marked vertically down the side as well,most likely a date code,but it can help to narrow the search down further.
.

[SMDFlea]

Re: Mini pc board no charging, no lights.

It could be a Panjit PJEC5V0V3FN2 https://www.badcaps.net/forum/showpo...64&postcount=3

[Cryogen]

Re: Mini pc board no charging, no lights.

Hi it's a Chinese generic mini pc not a laptop. I am trying to fix this for a friend, I only have the mobo and checking voltages and traces.

[Cryogen]

Re: Mini pc board no charging, no lights.

It could be a Panjit PJEC5V0V3FN2 https://www.badcaps.net/forum/showpo...64&postcount=3

breakdown voltage 10v

yep, seems about right. It's right next to the charging usb-C. he told me the 15v psu it came with it's pretty nasty cheap looking.


Do you know where can I get a pair here in the UK?

[SMDFlea]

Re: Mini pc board no charging, no lights.

Do you know where can I get a pair here in the UK?

No but these are jellybean parts. Try finding some with matching specs at farnell https://uk.farnell.com/c/circuit-pro...earchlookahead .If you find some matches but don`t want to buy from farnell just google the part numbers,or search for them on ebay.

[Cryogen]

Re: Mini pc board no charging, no lights.

No but these are jellybean parts. Try finding some with matching specs at farnell https://uk.farnell.com/c/circuit-pro...earchlookahead .If you find some matches but don`t want to buy from farnell just google the part numbers,or search for them on ebay.

Thanks for that.

I narrowed the search down to this SD05C TVS.
The only value I see way off it's the junction capacitance at 200 pico farad against the 3.5 stated on the original ones.

Will that really make any difference?

[SMDFlea]

Re: Mini pc board no charging, no lights.

Thanks for that.

I narrowed the search down to this SD05C TVS.
The only value I see way off it's the junction capacitance at 200 pico farad against the 3.5 stated on the original ones.

Will that really make any difference?

I don`t know. This might help https://toshiba.semicon-storage.com/...nal-lines.html https://www.microsemi.com/document-p...citance-in-tvs .
.

[Cryogen]

Re: Mini pc board no charging, no lights.

I don`t know. This might help https://toshiba.semicon-storage.com/...nal-lines.html https://www.microsemi.com/document-p...citance-in-tvs .
.

Without the schematics I will never know. What if I just solder a 3.5pF cap on those pads instead?

[piernov]

Re: Mini pc board no charging, no lights.

Higher capacitance can disturb high-speed communication lines, not recommended to go 2 orders of magnitude higher.

[Cryogen]

Re: Mini pc board no charging, no lights.

I agree. What do you mean exactly though? Opting for a 3.5pF cap or going for a slightly higher/lower esd diode?

[DynaxSC]

Re: Mini pc board no charging, no lights.

The diode seems to be this:

https://www.aliexpress.com/item/1005...d=AVhYgWpf3PRY

WS05DLC-B Marking 5B LC SOD-323 SMD ESD electrostatic protection diode

[SMDFlea]

Re: Mini pc board no charging, no lights.

The diode seems to be this:

https://www.aliexpress.com/item/1005...d=AVhYgWpf3PRY

WS05DLC-B Marking 5B LC SOD-323 SMD ESD electrostatic protection diode

Nice find,it seems to be the right one.The package is the same as well unlike the one i suggested