Re: APC Back-UPS Pro 900 Output short



Hi, sorry for the late answer.
I've rechecked mosfets with multimeter and they don't seem to be shorted.

I've 2 24V incandescent light bulbs, 3W each, can be ok for the test? If yes, where I need to connect it?
Attached there is a photo of transformer connections.

I don't have a ring tester (I didn't know it), but if it isn't too much expensive, I can buy it...

Hi all,
I got this UPS from a friend that after a fault replaced it with a new one.
The UPS is an APC Back-UPS Pro 900 (BR900GI).
I've bought 2 new 12V 9Ah batteries to test it and when I connect the main 230V input, relays click to turn on the UPS, then I press the power on button, other relays clicks to turn on everything, the lcd flashes for a moment and then it immediately shutdowns (relays click to turn everything off).

So I've disassembled it and checked on the board for shorted components.
Attached 2 pics of the primary board and a secondary small...

Re: HP Z600 PSU Delta DPS-725AB Dead

Hi all,
Here's an update after replacement components arrived.

Components replaced as suggested:
IC902
R901
C905
C907

PSU is fully working now, tested under stress and with several on/off cycles. For now everything is ok!

Thanks for your precious advices and for your time

Re: HP Z600 PSU Delta DPS-725AB Dead



Thank you for these information R901 is as fusible resistor, right? On the top it's written 10ohm F1J... Desoldered it, and tested: [U]totally open[/U], not 10ohm.
The replacement that I found is a FRN01WK0100A10 by Royal Ohm, can be good? If not and I'm wrong, let me know.

Thank youRe: HP Z600 PSU Delta DPS-725AB Dead



Thank you for these information R901 is as fusible resistor, right? On the top it's written 10ohm F1J... Desoldered it, and tested: [U]totally open[/U],...

Hi all,
I have an HP Z600 Workstation that worked fine until somedays ago. Now, it won't power up and the green led on the PSU is not turning on.

Pulled out the PSU from the chassis and opened it. No visibile signs of burned ICs from what i see.
The model of the PSU is a Delta DPS-725AB, and the PCB is a DPS-725AP.
I've made some high res photos that are attached.
I've done some general testing and I found IC902, that is a TNY279PN, was shorted (I think): drain-source resistance was about 2-3 ohms.
I've a brand new TNY279PN at home so I tested it and...

Re: New Members - please post your introductions here

Hi all!
I'm new to badcaps forum but I already know it for it's large forum topic full of very interesting things about electronic.
I'm an electronic enthusiast and a software developer, and in my free time I like diagnose and fixing every type of PCBs.
Thank you for this amazing forum!