Dead High Power HPC-560-A12S

[imaddicted2u]

I've had this broken power supply sitting around for a few years and would like to take a crack at fixing it. It is a High Power HPC-560-A12S. Sirtech is printed on the board as well as NO610 Rev.03. It seems it was marketed under the same model number by Sirtec. Does anyone know if there might be a schematic floating around for it. I contacted High Power and they won't give me one. Any help or pointers would be handy and appreciated.

It used to display the wattage in use.

So far I know the fuse is good and the full wave bridge rectifier on the board is getting 120 vac in and putting out 166 vdc out.

Here are some other pics of the board:


This is the manufacturer product page
http://www.highpowersupply.com/hpc560A12s.html

[stj]

Re: Dead High Power HPC-560-A12S

get it open and post some foto's

[fzabkar]

Re: Dead High Power HPC-560-A12S

Measure the voltage at the 400V capacitor. This should tell us if the APFC circuit is working.

[imaddicted2u]

Re: Dead High Power HPC-560-A12S

get it open and post some foto's

Thanks for reply.
A few pics are posted in the original post.
I don't measure any voltages from any of the power supply connectors.
On the back of the main board, I measure 120vac in to the bridge rectifier and 166 vdc out of it. So at least I know the board is getting power. The 166 vdc traces also go to a CM6800G on the daughter board. There doesn't seem to be any voltage on pin 13 (VCC) of that chip. It's hard to see under the heat sinks to trace things out.

[fzabkar]

Re: Dead High Power HPC-560-A12S

There should be a high value resistor or two feeding the Vcc pin of the CM6800G. The other end of the resistor should go to the positive pin of the bridge rectifier. These "startup resistors" often go open circuit. The 400V capacitor should have 166VDC at present, but will have around 380V when the APFC circuit is working.

See page 15 of the datasheet for an application circuit:

[stj]

Re: Dead High Power HPC-560-A12S

i dont see any pictures.
you didnt attache them correctly.

[imaddicted2u]

Re: Dead High Power HPC-560-A12S

Thanks. You are right, 166VDC at the cap right now. I'll try to track down the resistor next.

[imaddicted2u]

Re: Dead High Power HPC-560-A12S

i dont see any pictures.
you didnt attache them correctly.

Don't know, I can see them all in the forum, even when logged out.
I used insert image not attach files, is there a preference on this site?
I just attached them. Try now.

[stj]

Re: Dead High Power HPC-560-A12S

now i see them

[fzabkar]

Re: Dead High Power HPC-560-A12S

I don't see the original inline images in Opera, but they're OK in OffByOne and Firefox.

http://i65.tinypic.com/2vhymax.jpg
http://i64.tinypic.com/20hlwe8.jpg
http://i68.tinypic.com/2mc64uc.jpg
http://i66.tinypic.com/300sb4i.jpg
http://i68.tinypic.com/iz2stg.jpg

[stj]

Re: Dead High Power HPC-560-A12S

you need to get ALL the dust out for a clear inspection, because there has been a high-voltage flashover on the bottom of the board.

also, the big vertical board needs completely resoldering where it joins the main board.

[imaddicted2u]

Re: Dead High Power HPC-560-A12S

Haven't found any open resistors. I attached a pic of the back of the daughter board and added the traces as they feed through to the other side of the board. I'll try to track it out some more tomorrow.

[imaddicted2u]

Re: Dead High Power HPC-560-A12S

you need to get ALL the dust out for a clear inspection, because there has been a high-voltage flashover on the bottom of the board.

also, the big vertical board needs completely resoldering where it joins the main board.

I'll give it a good cleaning and resoldering tomorrow.

[imaddicted2u]

Re: Dead High Power HPC-560-A12S

Cleaned up, re-soldered both sides of daughter board to main board connector.
Plugged it in afterwards, still no power up.

[fzabkar]

Re: Dead High Power HPC-560-A12S

You need to follow the VCC pin (13) back to its source supply. Either VCC is shorted to GND (pin 10), or one of the feed resistors is open.

[imaddicted2u]

Re: Dead High Power HPC-560-A12S

You need to follow the VCC pin (13) back to its source supply. Either VCC is shorted to GND (pin 10), or one of the feed resistors is open.

Not convinced this is it but I noticed while measuring R33, it was intermittent depending on where and how hard I pressed. Tried re-soldering it but made no difference. There's nowhere local to buy components so I have to order one to try so I'll report back when I get it.
Thanks again.

[fzabkar]

Re: Dead High Power HPC-560-A12S

ISTM that R33, R34, and R35 are the feedback resistors that sense the output voltage. That's the function of the VFB pin (15). You need to locate the power feed to pin 13.

[robert]

Re: Dead High Power HPC-560-A12S

Is there any voltage on +5Vsb?

The standby converter also supplies power to the PWM controller, so if it doesnt work, nothing will.
There will be no "start up" resistor around the CM6800 in a typical PC power supply. There are 2 dividers for sensing line and bulk voltage but these are not used for supplying its Vcc, as it is supplied by a winding on the standby supply.

[imaddicted2u]

Re: Dead High Power HPC-560-A12S

Is there any voltage on +5Vsb?

The standby converter also supplies power to the PWM controller, so if it doesnt work, nothing will.
There will be no "start up" resistor around the CM6800 in a typical PC power supply. There are 2 dividers for sensing line and bulk voltage but these are not used for supplying its Vcc, as it is supplied by a winding on the standby supply.

Nope, there is no +5Vsb. If it provides the VCC for the CM6800, that explains why it doesn't track its VCC back to the 120 VDC at the bridge rectifier.
Thanks for the info, I'll try to figure out why there is nothing on the +5Vsb line and go from there.

[stj]

Re: Dead High Power HPC-560-A12S

see if it uses a startup capacitor