ATX Power Supply - Dell XPS ONE A2010 - DPS-200PP-164

[amosfolz]

Good evening all,
I am trying to repair an ATX power supply out of a Dell XPS ONE A2010. This is an all in one desktop computer. The power supply is a Delta DPS-200PP-164. I have been unable to find a schematic or anything helpful online. Repairing PCB boards is a hobby and I am slowly teaching myself. I can use a DMM and have an ESR meter, but no other test equipment.
I am looking for any advice on where to further investigate.

Here is what I've determined so far:

-5v output is OK
-12v output jumps around between 1v – 4v
-There is a “whining” or “hissing” noise when the power supply is turned on.
-There is an audible “clicking” noise coming from the PSU. It sounds like possibly a relay clicking on and off every few seconds.

I am not familiar or experienced enough with ATX power supplies to know where to investigate futher without a schematic. Any help would be appreciated.

Thanks,

Amos

[stj]

Re: ATX Power Supply - Dell XPS ONE A2010 - DPS-200PP-164

there are some potentially cracked solder joints on there, i would also be seeing what's hidden under the heatsinks incase their are any caps getting cooked.

[PeteS in CA]

Re: ATX Power Supply - Dell XPS ONE A2010 - DPS-200PP-164

It's about 9 years old, by the date code on the PCB. I doubt there's a relay in it. Are you running it with no load? That could give misleading results on your +5V and/or +12V.

When you write:

-5v output is OK
-12v output jumps around between 1v – 4v

Are you referring to the minus 5V and minus 12V outputs? Or are you using hyphens as "bullets" in a list? If the latter, it's misleading.

[amosfolz]

Re: ATX Power Supply - Dell XPS ONE A2010 - DPS-200PP-164

Sorry for the confusion. I was referring to the +5v and +12v outputs.
The +5v line was a steady +5.1v. I assumed that was probably acceptable.

The +12v line did not get above +5v, and jumps around between +2v to +4v.

I tested the power supply while it was plugged into the mother board. The hard drive was not connected to the motherboard at the time. Power to the hard drive comes off the motherboard on this unit instead of directly from PSU.

[CapLeaker]

Re: ATX Power Supply - Dell XPS ONE A2010 - DPS-200PP-164

Try measuring the secondary voltages without a load on it. Maybe something is putting a too big of load on the 12V rail (mainboard or whatever else is hooked up to the 12V rail on the PSU), or the 12V rail can't handle the load, because the capacitors are bad.

[PeteS in CA]

Re: ATX Power Supply - Dell XPS ONE A2010 - DPS-200PP-164

I wonder if the PSU is oscillating. If you're using a DMM, it could fool you into thinking the +5V is OK, when an oscilloscope or the AC scale of your DMM might show that it's not stable either.

Now, if the +5V really is clean and stable, I'd check for bad solder joints in the +12V current path (inductors, rectifier leads, output wires) and the health of the +12V rectifier.

[PeteS in CA]

Re: ATX Power Supply - Dell XPS ONE A2010 - DPS-200PP-164

I should add that while the +5V is the main O/P, Delta commonly samples both the +5V and the +12V rails for the feedback to the PWM (probably 384x family). So an imbalanced load could affect regulation on one of those rails. I doubt that's happening here, though

[Longbow]

Re: ATX Power Supply - Dell XPS ONE A2010 - DPS-200PP-164

Clicking and whining noises are typical of supplies that are trying to start up, but immediately shut down - repeating the sequence over and over. Good to keep in mind that Dell supplies have their own special pinouts for the connectors, they are not ATX standard supplies. Courteous of them.

[amosfolz]

Re: ATX Power Supply - Dell XPS ONE A2010 - DPS-200PP-164

Try measuring the secondary voltages without a load on it. Maybe something is putting a too big of load on the 12V rail (mainboard or whatever else is hooked up to the 12V rail on the PSU), or the 12V rail can't handle the load, because the capacitors are bad.

I tried using a jumper between PS-ON and ground and starting the power supply while it was not connected to anything else. It turned on for a few seconds and then immediately turned off.

I then plugged the hard drive into the system and the results were the same as what I originally posted.

[amosfolz]

Re: ATX Power Supply - Dell XPS ONE A2010 - DPS-200PP-164

I wonder if the PSU is oscillating. If you're using a DMM, it could fool you into thinking the +5V is OK, when an oscilloscope or the AC scale of your DMM might show that it's not stable either.

Now, if the +5V really is clean and stable, I'd check for bad solder joints in the +12V current path (inductors, rectifier leads, output wires) and the health of the +12V rectifier.

Would the component in picture_002 be the +12v rectifier?

The noise is coming from what I believe is a transformer, circled in picture_001.

The large capacitor in picture_03 made my DMM begin to make the same noise as is coming from the power supply when I touched the positive lead of the capacitor with either negative or possitive lead from DMM.

[Wester547]

Re: ATX Power Supply - Dell XPS ONE A2010 - DPS-200PP-164

No, that's the bridge rectifier on the primary side, which rectifies AC to DC. That primary capacitor is LTEC, which doesn't exactly inspire confidence. I would be wary of the output caps as well, as they are not from esteemed brands barring the Rubycons. I would also recommend testing for shorted rectifiers and inspecting the underside for bad joints.

[CapLeaker]

Re: ATX Power Supply - Dell XPS ONE A2010 - DPS-200PP-164

check the bottom of the board for bad solder joints. First post pic #4, there is a label with Q904 Q905, to the left of that label those solder joints don't look good.

[momaka]

Re: ATX Power Supply - Dell XPS ONE A2010 - DPS-200PP-164

The large capacitor in picture_03 made my DMM begin to make the same noise as is coming from the power supply when I touched the positive lead of the capacitor with either negative or possitive lead from DMM.

That large cap looks like an LTec brand. As Wester547 hinted, LTec doesn't exactly have a stellar reliability record... and most APFC circuits I've seen with a bad primary cap typically end up going kaboom

So the issue you are having could be that primary cap is starting to dry up and is causing the APFC to act up and make the noises you are hearing.

It could also be the caps on the secondary side, as other folks here suggested.

But before changing any caps, first check and reflow all solder joints that appear suspect. I see several of the larger components with what appears to be small crack rings on their solder joints.

[amosfolz]

Re: ATX Power Supply - Dell XPS ONE A2010 - DPS-200PP-164

I am hoping to get an adjustable temperature iron from the wife for Christmas. I was having issues when trying to remove the solder on this board as I do not think my iron was getting hot enough.

Thank you everyone for your input. I've been out of town for holidays but will give an update as soon as I get home and have a little free time to work on this.

[amosfolz]

Re: ATX Power Supply - Dell XPS ONE A2010 - DPS-200PP-164

I went ahead and replaced the large 450v 150uf capacitor and reflowed any solder joints I thought looked suspicious.

Just to avoid future issues I replaced the few other LTec caps I found on the board even though they tested good with my ESR meter.

The power supply is now putting out a steady +12v and +5v and the machine is booting up without issues.

Thanks everyone for your input and help with this, I really appreciate it.

Happy new year and blessings to everyone.

[Agent24]

Re: ATX Power Supply - Dell XPS ONE A2010 - DPS-200PP-164

Good to keep in mind that Dell supplies have their own special pinouts for the connectors, they are not ATX standard supplies. Courteous of them.

No, not all of them. Some do follow the ATX pinout just fine.

Which is even worse.

[aman2]

Re: ATX Power Supply - Dell XPS ONE A2010 - DPS-200PP-164

Hello, please can you tell me the value of ic901? I think it's a TNY, but no more, my DPS-200PP-164 is dead, ic 901 has a hole in full center, so more way to see it worth, thank you

[stj]

Re: ATX Power Supply - Dell XPS ONE A2010 - DPS-200PP-164

i think it's TNY208