HP Pavilion 6305 PSU

[stevo1210]

Hello All,

I have a "retired" HP Pavilion 6305 Desktop PC with a wierd shaped PSU. It uses the 20PIN ATX connector, but it just doesnt boot!.
I tested the fuse and it is fine. When i plug it into the wall, nothing happens, no boot, nothing. It just died one day when it was left on for a while.

Anyone got any ideas? It still works with a standard PSU though.

[linuxguru]

Re: HP Pavilion 6305 PSU

If it's a Bestec ATX-100 or similar, it can probably be revived by recapping all secondary caps. The key caps are 12.5 mm, which makes it easier. These PSUs were often found in the HP "Piglet" (small, fat, grey mini-tower with rounded edges) Pavillions and Brios.

[stevo1210]

Re: HP Pavilion 6305 PSU

Thanks Linuxguru for the advice, but it's not a Bestec power supply.
It is a Delta electronics DPS-110MB A REV:00, HP P/N 0950-2800.

I inspected inside it and it appears to have KZG chemicon caps, and none are bulging at all. The fuse is still intact actually. And yes, it's one of those small grey piglet tower ones.

There seems to be a lot of dust in it though. Most likely because it's been in a mechanic workshop and left on 24hours a day. It even smells like car oil !!!! everytime i touch around in there, my fingers even go black because of the oil dust in the air!!.

Could the dirty nonsense be the cause?

Thanks.

[Tom41]

Re: HP Pavilion 6305 PSU

Are you using the PSU in the same PC it came with? Sometimes you get PSUs that use the ATX-style connector, but the pinout is completely different. Plug it into a board with a standard ATX connector, or plug a 'normal' PSU into that board, and it won't work - or may even cause smoke!

Also check that the fuse in your mains plug hasn't blown; check that you are getting a proper 120v/240v AC supply through to the PSU. It may also be that the power button has become disconnected from the motherboard (or is faulty), so you can't turn it on. Try shorting the relevant pins on the ATX connector and see if it turns on.

[stevo1210]

Re: HP Pavilion 6305 PSU

Thanks Tom41, yes im trying to use the original "thinner" PSU with this HP computer, but unfortunately it is dead.

So for now im temporarily using a standard ATX PSU outside the case, and the HP seems to fire up well. I also tried this PSU in another PC, but it wouldnt budge.
The previous owner had left the computer on 24x7 and one day came to work to see it had "Died".

[kc8adu]

Re: HP Pavilion 6305 PSU

there are 2 470k resistors in it that go open.
one on the edge of the stand up board and the other nearby on main board.
this is the startup source for the pwm chip.
very common.
i use 1/2w in place of stock 1/4w

[PeteS in CA]

Re: HP Pavilion 6305 PSU

very common.

That's an understatement, . I'll bet a start-up scheme like that is in the TI-Unitrode datasheet and app notes for the UC384X family PWMs. Also check the (typically) 47uF-100uF cap in series with those resistors, and possibly, a zener may be across that cap.

Beyond that, do you have +5V Stby? If not, that's where the problem is.

[stevo1210]

Re: HP Pavilion 6305 PSU

Ok, i got some images, i hope this helps....


Thanks.

[bobcaygeon]

Re: HP Pavilion 6305 PSU

If you opt to not repair it yourself, you can try buying this P/S: http://www.newegg.com/Product/Produc...82E16817104112. I've bought two of these for two different HP Pavillions over the course of a year and they're still running fine. I do recall though, when I took a peek inside the ventholes before installing them, they did not have the best choice of caps.

[PeteS in CA]

Re: HP Pavilion 6305 PSU

Wow, that was made in May of 1998.