Delta DPS-800GB Power Supply No Power

[torgeson5kqs]

I have a few of these redundant power supplies from some HP servers that are not responding and wanted to know if anyone has worked on them or had much luck getting them back on their feet. The Delta supplies are typically pretty well made and this is no different. I've check the fuse, MOV's, etc. and no obvious signs of damage that I can tell. Caps look good, rectifier checks out too. Let me know if you have any info on these. The connector to this power supply is a circuit board with pins on it, not your typical pin type connector. I've seen conflicting resources on the web that show which pins to short.

[Toasty]

Re: Delta DPS-800GB Power Supply No Power

Bad startup cap(s). First clue was NO standby voltage.

Everything is Ruby's or Chemi-con's except the bloody one that fails which is an 100uF Ltec. Reads open, as in pF instead of uF...

Nice job shootin' yerselves in the foot there Delta. jeeze...

Fans need to be removed first. Then the power plug needs to be separated from the chassis. It is caulked in place -underneath- the socket. Joy. Xacto knife time. It then needs to be pulled out so its' wires can pass through the slot in the chassis while the main board is removed.

It's a real bastard of a cap to get to because of the cramped conditions, and some super-fine wiring going to the daughter board. Trust me, you don't want to screw with them. (hair fine in Teflon® insulation)

This is a double-sided board, so lots of heat (air) plus the hot vacuum desolder tool.

The heat sink that needs to come out has a finned spreader that spans several components and must be removed first. Then the heatsink complete with the bridge, thermistor, and switchers on it. Once you get the thing loose and out a bit, loosen the bridge screw a bit and and swing it aside to expose the screw holding the thermistor. Remove the screw & nut and detach the thermistor so it does not get damaged.

Replace both caps that are in the heat-shrink tubing, next to the daughterboard. (You're there, do you -really- wanna go back later for 50¢ worth of caps???)

Reverse the above to reassemble.

T

[torgeson5kqs]

Re: Delta DPS-800GB Power Supply No Power

Wow, all that for 50 cents worth of caps. Thanks for the diagnostic toasty, I will attempt it myself and see if I have the same success. I'm concerned about those fine wires and breaking them. I don't have an air gun but a decent weller 85 watt soldering station with 85 watt pen and a large tip for better heat transfer. I let you know if this works. Thanks again for all your help.

[safainla]

Re: Delta DPS-800GB Power Supply No Power

Could you elaborate a little bit more on the exact location of those caps or maybe provide on-board cap number? I am attempting to fix two of these and im half way through it. Thanks

[Toasty]

Re: Delta DPS-800GB Power Supply No Power

>> the heatsink complete with the bridge, thermistor, and switchers on it. <<

>> Replace both caps that are in the heat-shrink tubing, next to the daughterboard. <<

Don't have the cap numbers nor pictures.

T

[seanc]

Re: Delta DPS-800GB Power Supply No Power

Ooh useful thread.

I've had one customers DL380 G5 'kill' two of these. Always the one that was installed in the second slot. It would start sending me alerts that the power supply had lost power, then reconnected and so on.

Interesting to know it's not just us.

[Toasty]

Re: Delta DPS-800GB Power Supply No Power

Heh. You're still alive!!

We have some unfinished business with an iMac PSU, no?

T

[seanc]

Re: Delta DPS-800GB Power Supply No Power

Yes I still have that blasted thing. I've no reason to fix it now, apart from curiosity, might get round to it one day.

[Toasty]

Re: Delta DPS-800GB Power Supply No Power

LOL!

Well, I have all the Euro-varieties here now, so I can better assist you.

T

[Toasty]

Re: Delta DPS-800GB Power Supply No Power

re: Thread subject.

It has been suggested to "upgrade" these to the P/N: 379124-001 model. Typically going for <$50 new so repair is a waste of time. There are tons of them on flea-bay.

Confirm with seller that it bears the number above. Many times they are listed with all the numbers as interchangeable.

T

[Blerog]

Re: Delta DPS-800GB Power Supply No Power

Unfortunatley in my experience the 379124-001 is just as unreliable as the older models.

I have a few of these power supplies here that are causing random unexpected shutdowns even after the two caps are swapped out. Any ideas? EDIT: Just to clarify, I mean on the older model, they are afterall quite different. Some of them have been in to HP for repair in the past and it would appear that they have swapped out the Surface mount diode underneath the Ltec cap at the same time as the cap. Could the faulty cap be killing the diode or vice versa and making the power supply unstable?

Cheers,
Owen

[Toasty]

Re: Delta DPS-800GB Power Supply No Power

Have you eliminated any problems with the server versus the power supply?
Does swapping power supplies make the server stable?
Does a test of the power supply on the bench reveal any issues?
There may be an issue of "hyper-sensitivity" or "too tight a tolerance setting" to system faults that could cause these to shut down. The programmed chip may be an issue, IMO.

The one I had was dead on standby. What do you find?

Unaware of the diode issue. Have you found them with that diode blown? Are you sure it wasn't done by the factory for convenience because of the proximity to the bad cap? Or that the cap repair makes it "look" like it was replaced?

T

[Blerog]

Re: Delta DPS-800GB Power Supply No Power

Have you eliminated any problems with the server versus the power supply?
Does swapping power supplies make the server stable?
Does a test of the power supply on the bench reveal any issues?
There may be an issue of "hyper-sensitivity" or "too tight a tolerance setting" to system faults that could cause these to shut down. The programmed chip may be an issue, IMO.

The one I had was dead on standby. What do you find?

Unaware of the diode issue. Have you found them with that diode blown? Are you sure it wasn't done by the factory for convenience because of the proximity to the bad cap? Or that the cap repair makes it "look" like it was replaced?

T

Hi,
I have close to 200 faulty supplies here, Tested in a server some of them are showing intermittant shutdowns as the fault and some of them are showing no power LED and flashing internal and external health lights on the server.

My test server is 100% stable with my known good test supply fitted. It is possible that the Diode just looks like it has been replaced, the strange thing is it would appear that the ones that have been repaired in the past by HP have a slightly different Diode fitted (looks slightly "beefier") I must admit though i have not got a magnifying glass out to see if i can see any markings on them and i have yet to find one with the diode Blown.

I have only attempted rapair on 5 so far, 2 of them were showing the intermittant shutdown fault and are the same supplies that are still showing this fault, The capacitor in one of them was visibly bulged, and in the other it was reading way off. The other three were showing the no power fault with the flashing health lights, these three have all been sucessfully repaired. I reacon either the two faults are not related or the cap starting to go is taking something else out with it on some supplies. I guess i will have to investigate further.

Cheers,
Owen

[Blerog]

Re: Delta DPS-800GB Power Supply No Power

I have just had a look at one of the supplies that is still unstable. powered it up on the bench and 5VSB, 3.3V, 12V are all spot on. -12V is only showing -10.29V though. Time to head home now for the weekend but this supply was making the server unstable, it was restarting itself every hour or so when i tested it after the swollen cap was replaced.

Cheers,
Owen

[Blerog]

Re: Delta DPS-800GB Power Supply No Power

Quick update.
the power supplies i was still having problems with all have united chemicon KZE and / or KZH caps on the output and these were bad, all supplies perfectly stable after swapping these out. They were not bulged, except 1 that was slightly bulged on the bottom which is what tipped me off that it may be the problem. Normally i only see the KZG's failing but i guess i will just start ripping all UC caps out in future.

[Toasty]

Re: Delta DPS-800GB Power Supply No Power

Good catch! Thanks for the heads up! Really odd to find those series failing. What did you use to replace them?

Going back to the diode, I suppose HP found some failed and were just replacing them as a matter of course on any that come in.

T

[Blerog]

Re: Delta DPS-800GB Power Supply No Power

Hey,
The capacitors were replaced with rubycon's of the same value, cant remember what series off the top of my head though. This fixes the supplies that were experiencing "unexpected shutdowns". It is strange though, the ones with the bad caps on the outputs do not use ltec startup cap, they have rubycon's in this position. I guess you are right about the diode aswell, though i have yet to find one where this is faulty.
Owen

[mockingbird]

Re: Delta DPS-800GB Power Supply No Power

the power supplies i was still having problems with all have united chemicon KZE and / or KZH caps on the output and these were bad, all supplies perfectly stable after swapping these out. They were not bulged, except 1 that was slightly bulged on the bottom which is what tipped me off that it may be the problem. Normally i only see the KZG's failing but i guess i will just start ripping all UC caps out in future.

KZE and KZH are both reliable... Maybe the servers were being run in an inaequately ventilated area. Still, I would be very interested to see pics of the caps you replaced. Did you measure them?

[PeteS in CA]

Re: Delta DPS-800GB Power Supply No Power

I would lean toward the KZHs as the prime suspects. I've had good luck with KZEs in my torture tests.

[Blerog]

Re: Delta DPS-800GB Power Supply No Power

The server that i use for testing is in my lab, it is kept at a constant 21*C and during testing the server is on a workbench alongside a couple of other servers i use for testing, there is about 1ft each side and at the back of the server.

The server Runs perfectly stable with my test power supply. The faulty supplies were tested in the server to identify the problem was as had been reported before any repair attempts were made.

I did not measure the cap's, It is quite possible it is not all of the cap's in that area that are going bad, i just figured one was bad on the first supply so when i had it appart and all the fet's / heatsinks desoldered to get at it i would change the lot.

Before swapping out the caps my -12V was at around -10V on all three of the supplies i have done this too so far, After it was sitting around -12V as it should be, all other rails were reading the same.