Dell U3011 - Troubleshooting the Power Supply board PS-2201-3-HF

[jason123]

Hi folks,
I see many having issues with the U3011 monitor display (Westinghouse guts?)

I have one that would work if I unplug power from wall every once in a while. Was like that for about 3 months - Now, it doesn't turn on at all (front LEDs), but no backlight or other signs of life.

I replaced the Power Supply PS-2201-3-HF board and that took care of the problem.

I'm trying to repair the PS-2201-3-HF board. It has 2 connectors sets (top and bottom)
Bottom set seems to be just 24V and GND with ENA, ADJ, and HDCR

Top Connector, P802, is identical, but P803 has 5, GND, 24_EN

I buttoned up the Monitor so I'm troubleshooting this board on my workbench. To turn all the supplies on, I'm assuming I tie 24_EN to 5V (with a small resistor)?

Do I have to do anything with the ENA and HDCR pins??

Any common failures that anyone can share on this board?
Thanks

[jason123]

Re: Dell U3011 - Troubleshooting the Power Supply board PS-2201-3-HF

Looks like 24_EN on P803 is not connected to anything. So I'm guessing the 24 V comes on when the "ENA" is tied high.. So I shorted it to +5V (which does come on), but the 24 V never comes up. Voltage across large Cap doesn't change - 164 V DC. Is this a PFC circuit issue? Looks like this uses the Fairchild FAN7529B. Schematic anyone?
Thanks

[jason123]

Re: Dell U3011 - Troubleshooting the Power Supply board PS-2201-3-HF

Ok, update (to myself ) ENA is simply pass through - maybe to turn on the inverter power? I tied 24_EN to 5V, and now the PFC is working and voltage on large cap is 384 VDC. However the 24 V only comes up to 5.2 V.. and gradually drops to 3 and continues to drop. Does the 24V require a load on it?

[jason123]

Re: Dell U3011 - Troubleshooting the Power Supply board PS-2201-3-HF

I'm not seeing a controller between the 5V to the 24V. Simply a transformer, some diodes and resistors and caps. Is that possible? are they modulating the 5V and transformer turn ratio sufficient to generate 24V then filter? is that it?

[captainKKK]

Re: Dell U3011 - Troubleshooting the Power Supply board PS-2201-3-HF

Did you check that white fuse in your picture? close to R107.

[jason123]

Re: Dell U3011 - Troubleshooting the Power Supply board PS-2201-3-HF

That is labeled C107 - I know it's a bad photo. I didn't.. I will shortly and let you know. Seems that the PFC circuit is working - Large Cap voltage goes from 164 to 384 VDC.

[jason123]

Re: Dell U3011 - Troubleshooting the Power Supply board PS-2201-3-HF

Cap C107 checks out.

[captainKKK]

Re: Dell U3011 - Troubleshooting the Power Supply board PS-2201-3-HF

What are the voltages on P802 and 803 when it's turned on?

[jason123]

Re: Dell U3011 - Troubleshooting the Power Supply board PS-2201-3-HF

Hi captainKKK... I found a couple of bad solder joints (actually arching as I move the board) so touched those up, and now 24V comes up to 24.67 V.. However, there is a chatter or relay sound (though I can't find a relay on the whole board)- Audio recording attached.. Seems shorting 5 V to 24_EN is too strong. When I use larger resistors the chatter goes away, but the rail only reaches 20 or 21 V. Any idea what resistance I should put between 5 and 24_EN?
Thanks

[jason123]

Re: Dell U3011 - Troubleshooting the Power Supply board PS-2201-3-HF

Any help here is appreciated folks.. I'm still having the "Clicking noise" coming out of the transformer??? I replaced the parallel Cap on the primary, and that didn't fix the issue. I'm thinking maybe internal arching? However I can't find a replacement transformer. Can anyone confirm that this indeed could be coming from transformer?

[Topcat]

Re: Dell U3011 - Troubleshooting the Power Supply board PS-2201-3-HF

Sounds like it to me. I think I have a spare power supply for one of these in the attic, I have one with a broken panel that I've bilked parts out of.

[jason123]

Re: Dell U3011 - Troubleshooting the Power Supply board PS-2201-3-HF

Sounds like it to me. I think I have a spare power supply for one of these in the attic, I have one with a broken panel that I've bilked parts out of.

Hi,
thanks for the post.. would love to get my hands on a supply. I can't find a replacement transformer for this board. I search all over the internet and no one seems to carry that part number

[Topcat]

Re: Dell U3011 - Troubleshooting the Power Supply board PS-2201-3-HF

Hi,
thanks for the post.. would love to get my hands on a supply. I can't find a replacement transformer for this board. I search all over the internet and no one seems to carry that part number

I'll poke around tomorrow and see if I can locate it.

[Topcat]

Re: Dell U3011 - Troubleshooting the Power Supply board PS-2201-3-HF

Hi,
thanks for the post.. would love to get my hands on a supply. I can't find a replacement transformer for this board. I search all over the internet and no one seems to carry that part number

You're in luck, I found 2 of them. Shoot me a PM if you want one.

[harlock]

Re: Dell U3011 - Troubleshooting the Power Supply board PS-2201-3-HF

You're in luck, I found 2 of them. Shoot me a PM if you want one.

Are you parting with the second one? this is my first post so i guess i will be able to pm after this.

thanks

[Topcat]

Re: Dell U3011 - Troubleshooting the Power Supply board PS-2201-3-HF

Are you parting with the second one? this is my first post so i guess i will be able to pm after this.

thanks

Yea, I could be talked out of it.

[blankdisplay]

Re: Dell U3011 - Troubleshooting the Power Supply board PS-2201-3-HF

Gentlemen, apologies for bumping an older thread, but I'm curious if anyone has isolated a common fault with this board?

A little googling and youtube, reveals it seems to be a common fault and paying around $70 to $110 US to import a board is a common fix for those technically minded.

As someone with a soldering iron and multimeter, I'd at least be willing to take a crack at repairing it if there seems to be a common component that gives up.

Any thoughts?

Thanks for your time, it's appreciated!.

[momaka]

Re: Dell U3011 - Troubleshooting the Power Supply board PS-2201-3-HF

Any thoughts?

So would that be the same issue as the O/P's? - i.e. PSU clicking and/or not turning On? If no, you may want to start a new thread, detailing the new/other issues you're having. And whichever the case, some good high-quality pictures of the PSU board uploaded here would be helpful for us to see and try to troubleshoot alongside.

[RecentlyShocked]

Re: Dell U3011 - Troubleshooting the Power Supply board PS-2201-3-HF

Anyone looking for U3011 power supply repair tips should take look at this older thread on this forum. It contains two possible repairs.

https://www.badcaps.net/forum/showthread.php?t=56411

[blankdisplay]

Re: Dell U3011 - Troubleshooting the Power Supply board PS-2201-3-HF

Thanks my reply to this went missing somehow!

I'm off into the other thread, thanks so much for the forum.

Fingers crossed, I posted a heap of pics