what is this laptop SMD?

[saturday tech noob]

What is this copper coloured SMD labelled PD5 in the picture?
I have a netbook with no signs of life and thought they might be the problem. There are 4 of them near the battery and power terminal, some of them have 19v going in and coming out and some have 19v on one side and a couple hundred mV coming out.

[goontron]

Re: what is this laptop SMD?

surface mount zener diodes.

[Duncanbest]

Re: what is this laptop SMD?

FYI

LL4148

https://www.badcaps.net/forum/showthread.php?t=24098

[lti]

Re: what is this laptop SMD?

I think a zener diode would have a different colored band or some other markings. That looks like a 1N4148 or a similar diode.

[popeye]

Re: what is this laptop SMD?

The schematic will tell you what it is.

[budm]

Re: what is this laptop SMD?

+1 for 1N4148.
"some of them have 19v going in and coming out and some have 19v on one side and a couple hundred mV coming out." That is depends on how it is being used in the circuit so it does not mean it is bad.

[darkdead]

Re: what is this laptop SMD?

Laptops never use 19v inside they use a DC to DC converter and you get the B+ power used for be over 18.5v the B+ power also come from another DC to DC converter conected to battery.
You need the schematic of the board or atleast a photo near AC in.
Soory for my languaje (spanish)just joined today becuse was looking some info about a hp 27 inch monitor i win on ebay for fix and can wait for see whats is inside of it and the forum got some awesoem pics of the pcbs and if i fix it i will post the work around.

[darkdead]

Re: what is this laptop SMD?

BTW 1+ 1N4148 and it enver fail the isues from no light is a bios issues must check the 3,3v on bios or the usual shorted cap on any DC to DC converter.