HP 611483-001 Force on

[s_henya]

Hi guys,

A freind asked me to help out with this HP Desktop, it has no power issue.

i wanted to test the psu but it has diffrent connectors than the 24 pin standard psu.

is there any way to test it in order to rule out MB fault?

tested the fuse and voltage on the main cap showed 309VDC.

[s_henya]

Re: HP 611483-001 Force on

found this info on HP's website.3
i tested it and indeed the PSU is faulty.

i will later add info maybe i will be able to fix it.

[sam_sam_sam]

Re: HP 611483-001 Force on

With HP power supply you will have a hard time finding one maybe on eBay but probably not a new one

Or the other option is to repair the one you have

Here is what I would do

Take the power supply out and take it apart and see any thing burn up and if you have any caps that pop there tops

If you have an ESR meter check all of your small value UF cap 100uf and lower for real high ESR readings 1.0 or higher would probably change them

Please post some photos of power supply board or boards

[PeteS in CA]

Re: HP 611483-001 Force on

It looks like that power supply is made by at least 3 vendors, AcBel, Delta Products, and Lite On. It has two 16A +12V outputs, a very low current -12V output, and a 1.3A +12 Standby output. It looks like the pic in your second post grounds (black insulation wire) the PSON# signal (green insulation wire).

From the pictures I've seen, it looks like the yellow wires are one +12V output, and the brown wires in that 4-pin connector is the other +12V output.

Your next step should be to check to see whether the +12 Standby output is working. Just put one meter lead to a black ground wire and with the other check each of the other wires. If the chassis is connected to output ground, you can lay the chassis on you meter probe tip to have both hands free.

If you have +12V Standby, the problem is in your main inverter circuit. If you do not, you need to fix that before you can find out if the main inverter works.

In either case, common points of failure are the small electrolytic capacitors in the Standby regulator circuit and in the main output controller circuit. Another common thing to look for is whether the output capacitors have either vented or have swollen tops.

[s_henya]

Re: HP 611483-001 Force on

Hi guys, for now i bought a new PSU for 125$ locally,

But i still wish to fix this one as a spare.

None of the caps lookes swallen, but i will test them with the ESR meter anyway.

i will update with the results...

[s_henya]

Re: HP 611483-001 Force on

I tested about 5 caps 2x22u 25v, 2x120u 50v, 1x 100u 25v all showed good capacitance and ESR.
So im guessing all the rest of the 16v caps are good.

i searched for the standby voltage and got nothing.

any more ideas would be great!

[sam_sam_sam]

Re: HP 611483-001 Force on

What is the voltage at the main filtering cap ?
That across the cap terminal please be careful doing this
You will have some high voltage there

[PeteS in CA]

Re: HP 611483-001 Force on

What is the voltage at the main filtering cap ?
That across the cap terminal please be careful doing this
You will have some high voltage there

Per the OP, 309V. It's a wide range unit, but I haven't been able to find if it's active PFC. The common output voltage for APFC is around 400V. So if that unit has APFC, the PFC stage isn't working. OTOH, if that's an auto-ranging unit, 309V could be OK.

If it has non-functional APFC then figuring out why is the first problem. If the 5VSB is down, so also are the internal housekeeping supplies. All in all, checking the 5VSB seems to me the first place to start, since that circuit supplies V(cc) for the PFC and PWM controllers as well as output supervisory circuits.

He said the 5VSB isn't present. What to do next depends on what type of Standby controller the PSU uses. Find out what it is and find a datasheet. Usually that has a sample circuit that can show what to look for. Understand the controller, figure out what voltages it needs and what can shut it down.

Pictures of that area of the circuit could be extremely helpful for us to make suggestions.

[s_henya]

Re: HP 611483-001 Force on

i found these ICs, i don't know who is the 5v standby controller.
IC501: TNY279PG
IC100: CMS6502THH+X
IC400: PS25A
IC900: WT7038

If that helps, tell me which one is it and i will take more clear pictures of that area.

[PeteS in CA]

Re: HP 611483-001 Force on

You could have learned that in a few minutes by Googling those part numbers. It's U501. I suggest a thorough read of Power Integrations' datasheet. It will tell you how the device works.

[s_henya]

Re: HP 611483-001 Force on

The Tinyswitch IC reads the following:

Drain 308vdc
source 0vdc
ENA 2.44vdc
BP/M 6.31vdc


another possible test points?

[momaka]

Re: HP 611483-001 Force on

Here is the datasheet for the TNY279PG chip:
https://cdn.badcaps-static.com/pdfs/...b56d9fb7b3.pdf

Go to page 8 and compare the sample circuit with the one in your PSU. There should only be a handful of components connected to the EN/UV and BP/M pins. Check those components and make sure they are fine - that is, resistors should read the same or lower in resistance (if higher, make sure they are not over indicated tolerance), diodes should show a normal diode reading one way (may have to pull diode if you get a reading both ways), and caps should NOT show short-circuit (if they do, pull those caps and test out of circuit).

If you find nothing, have a look at the secondary side rectifier (check to see if the rectifier/diode is good and not shorted), as well as the Zener or shunt (typically 431). If your PSU uses a 431 shunt for the 5VSB feedback regulation, just replace it with another. Almost any PC PSU has a 431 shunt somewhere, so if you have some spare PSUs, you can try getting it out of there.

[PeteS in CA]

Re: HP 611483-001 Force on

Referring to the schematic momaka referred to, changing zener VR3 to a 3.9V or 4.3V part and the R6 and R4 resistor values would make it it a 5V output voltage. So, look at the voltage at the equivalent of D7-C. It should be ~5VDC. If it's something else, there may be a problem in the VR3-R6-R4-U2 photo-diode area. If it's ~0V, the TNY279PG is not switching at all. If it's ~5V but there is no 5V Stby, there is an open between D7-C and the 5V Stby pin of the connector.

[s_henya]

Re: HP 611483-001 Force on

Referring to the schematic momaka referred to, changing zener VR3 to a 3.9V or 4.3V part and the R6 and R4 resistor values would make it it a 5V output voltage. So, look at the voltage at the equivalent of D7-C. It should be ~5VDC. If it's something else, there may be a problem in the VR3-R6-R4-U2 photo-diode area. If it's ~0V, the TNY279PG is not switching at all. If it's ~5V but there is no 5V Stby, there is an open between D7-C and the 5V Stby pin of the connector.

Hi Pete,

im still struguling with debbuging of this problem.
i tested every resistor, diode in the area and found nothing wrong.

i couldnt really understand everything you wrote, if you want me to measure voltage at a specific point please repeat again.