Power Supplies a cautionary tale

Parkside

New elf
Joined
Jan 20, 2011
Messages
35
Location
Edinburgh
Thought it worth flagging these up, no names on the supplier, they took the issue seriously as well , don`t believe they stock this type of supply any longer.

But should you encounter one out in the wild , HP power supplies, not that HP, those people at Hong Peng, 5V 6A power supply.

Had a batch of them in, first one goes bang, literally, spike takes out a dimmer on the same ring at the time.

Second one goes on isolated workshop supply and oscope, starts at around 30V then settles over a few seconds to around 4.6V with about a volt of sawtooth ripple superimposed.

Third one gets the lid opened:

http://dl.dropbox.com/u/28439610/IMAG0727.jpg

http://dl.dropbox.com/u/28439610/IMAG0729.jpg

http://dl.dropbox.com/u/28439610/IMAG0733.jpg

Yup, it looks like a power supply recovered from the Titanic , the muddy crud is OEM crud...

Common mode choke is missing and couple of nuts on the heatsink means they have actually been adapted after being recovered from bottom of a puddle..

There is quite a lot of energy in a switch mode power supply, some the components can be run under quite a lot of stress, its probably worth not cheaping out on PSUs...

Cheers
Adam
 

AAH

I love blinky lights :)
Community project designer
Joined
Dec 27, 2010
Messages
3,456
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Eaglehawk
If that isn't a dry solder joint on img 733 on the pad adjacent to the blue MOV visible through the hole then it probably soon would be. pretty ironic when it looks like the whole pcb has been wet ;)
 

fasteddy

I have C.L.A.P
Global moderator
Joined
Apr 26, 2010
Messages
6,645
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Albion Park NSW
Thats a great example of the varying quality and controls coming out of China, with this one being a great example of how bad it can be.
 
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