![]() |
|
|
Thread Tools | Display Modes |
![]() |
#1 |
New Member
Join Date: Dec 2017
City & State: Pavia
My Country: Italy
I'm a: Hobbyist Tech
Posts: 6
|
![]() 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 the drain-source resistance was about 5.5Mohms. Thinking it was the problem, I replaced the IC on the PCB, but the PSU still not working. I've replaced also the 100nF capacitor on the BP/M line but nothing changes. Voltage on the main big caps is about 322V, I marked it on the photos. Other reads over the TNY279PN: EN/UV voltage: 1.89V BP/M voltage: 1.80V (from the datasheet I've read that it should be over 5.85V, I'm right?) Main cap positive-Drain: ~320V Drain-Source voltage: 3.90V I think this circuit with TNY is for 5Vsb but I'm not sure, can you confirm? ![]() What can be the problem, and what could I test to find it with you? Thanks all in advance Last edited by arrgh; 04-02-2021 at 07:45 AM.. |
![]() |
![]() |
![]() |
#2 |
Great Sage 齊天大聖
Join Date: Dec 2009
City & State: Europe
My Country: some shithole run by Israeli agents
I'm a: Professional Tech
Posts: 26,855
|
![]() check fuses and fuseable resistors,
and replace any cap less than 100uf related to the chip |
![]() |
![]() |
![]() |
#3 | |
Badcaps Veteran
Join Date: Jun 2012
City & State: ☻
My Country: Canada
I'm a: Professional Tech
Posts: 8,162
|
![]() Quote:
Last edited by R_J; 04-02-2021 at 10:24 AM.. |
|
![]() |
![]() |
![]() |
#4 | |
New Member
Join Date: Dec 2017
City & State: Pavia
My Country: Italy
I'm a: Hobbyist Tech
Posts: 6
|
![]() Quote:
![]() The replacement that I found is a FRN01WK0100A10 by Royal Ohm, can be good? If not and I'm wrong, let me know. Thank you |
|
![]() |
![]() |
![]() |
#5 |
Badcaps Veteran
Join Date: Jun 2012
City & State: ☻
My Country: Canada
I'm a: Professional Tech
Posts: 8,162
|
![]() Yes, the resistor will work, but I will almost guarantee the ic is bad, I would also replace C905 & C907, since this is the standby circuit, it is on all the time and the caps can dry out over time (they could be ok but they are cheap to replace)
|
![]() |
![]() |
![]() |
#6 |
New Member
Join Date: Dec 2017
City & State: Pavia
My Country: Italy
I'm a: Hobbyist Tech
Posts: 6
|
![]() 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 ![]() |
![]() |
![]() |
![]() |
#7 |
Badcaps Veteran
Join Date: Jun 2012
City & State: ☻
My Country: Canada
I'm a: Professional Tech
Posts: 8,162
|
![]() Thanks for the feedback, Glad to here it is working, long live the power supply
|
![]() |
![]() |
![]() |
#8 |
New Member
Join Date: Aug 2021
City & State: Campinas
My Country: Brasil
Line Voltage: 110/220VCA, 60Hz
I'm a: Knowledge Seeker
Posts: 1
|
![]() Hi!
I am new on BadCaps community. I work on a research center in Brazil, and we have several HP Z600 workstation. Many of them are presenting failures on power supply model Delta DPS-725Ab. So I will appreciate if someone could provide the schematic diagram of Delta DPS-725Ab power supply. I thank you for helping. Regards Wilson Carvalho Jr |
![]() |
![]() |
![]() |
#9 |
New Member
Join Date: Aug 2022
City & State: Maracay
My Country: Venezuela
I'm a: Knowledge Seeker
Posts: 1
|
![]() Salutes, I have a similar problem with DPS 725AB, it starts with green led, ażnd give voltage output for about 20 econds and then goes off totally, I am not sure what the standby cables are though (green and violet?), I someone can orientated me please
|
![]() |
![]() |
![]() |
#10 |
Badcaps Veteran
Join Date: Aug 2005
City & State: San Jose, CA
My Country: USA, Unsure of Planet
Line Voltage: 120VAC, 60Hz & 115VAC, 400Hz
I'm a: Professional Tech
Posts: 3,399
|
![]() I see that this is not a P/S with a standard 20- or 24-pin ATX connector. However, if Delta followed ATX-style color coding inside the P/S, purple would be the 5V Standby.
Another question, server power supplies sometimes will run for several seconds and then shut down if the fan never ran. Does the fan run during the 20 seconds it has output voltage?
__________________
PeteS in CA Power Supplies should be boring: No loud noises, no bright flashes, and no bad smells. **************************** To kill personal responsibility, initiative or success, punish it by taxing it. To encourage irresponsibility, improvidence, dependence and failure, reward it by subsidizing it. **************************** Anti-Covid-Vaxxer pig crap claim/prediction, Doctor: Heart Failure from mRNA Jabs "Will Kill Most People" | Principia Scientific Intl. ; Dr. Geert Vanden Bossche Warns COVID-19 Jab Injuries and Deaths Will Soon "Collapse Our Health System" (VIDEO) ; Fully Vaxxed May 2021; Since that time I've done 7 5Ks, 1 8K, 8 10Ks, and 4 half marathons |
![]() |
![]() |
![]() |
Thread Tools | |
Display Modes | |
|
|