Delta DPS-160QP Power Supply

[John McGivern]

This power supply is for a HP Pavilion Slimline PC.

1 Turn on 330vdc at high voltage cap.
2 No 5vstby or any low voltage rails.
3 PWM chip is UC3845B.
4 PFC chip is 1CE1PCS02.
5 Switcher TNY267.
6 There are 4 optocouplers. PC123. and TL431.

I am retired and a novice at electronics.
Any help would be much appreciated and a schematic would be handy if anyone knows where to get one.

Many thanks in advance, John.

[stj]

Re: Delta DPS-160QP Power Supply

you need standby to drive the rest of it,
start with the cap next to the TNY
if it wont give 5v replace the TNY and try again.

[John McGivern]

Re: Delta DPS-160QP Power Supply

Stj many thanks.

[CapLeaker]

Re: Delta DPS-160QP Power Supply

The tny is always running to produce stby. The rest I second what stj said.

[John McGivern]

Re: Delta DPS-160QP Power Supply

Hi, is there anyway I can test this chip as I don’t have one readily available and don’t want to buy single parts and shotgun the circuit it would take weeks due to delivery dates and cost more than a second hand power supply. I wanted to learn how to locate the exact component or components, many thanks John.

[stj]

Re: Delta DPS-160QP Power Supply

you can check it's getting power by looking at the datasheet,
it wont do anything if the startup cap is bad though.

[CapLeaker]

Re: Delta DPS-160QP Power Supply

These TNY’s blow up but they like to fail just dead too. So all you can do is make sure it is getting voltage and if nothing happens, replace it. Just a piece of advice, when you do replace it, make sure to clean very well the flux off the bottom and make sure there is nothing in between the pins. Happened just a while ago somebody replaced a TNY cleaned up with alcohol and a paper towel. A tiny pice of paper towel got stuck between the pins and the PSU was dead again after a day or so.

[John McGivern]

Re: Delta DPS-160QP Power Supply

Hi I have just been going over this board I removed the 2 large heatsinks tested 6 transistors all seem ok.
With them removed I found a short across C101 and C301 is this ok?
Anyone know the values and voltage.
LM324 appears shorted pins 5 and 6 shorted to pin11.

[CapLeaker]

Re: Delta DPS-160QP Power Supply

Got no idea what c101 and c301 are. Your pictures aren’t good enough to see. Upload some straight shot high resolution pictures, so we can see something. As for the LM324, pin 5 and 6 may not be used, so instead of let them floating around, they are connected to GND in order to disable that section of the IC. Check the traces where they go.

[John McGivern]

Re: Delta DPS-160QP Power Supply

CapLeaker some new pics hope they are good enough. I removed the transistors but the short is still there Transistors test good. I have a 50 ohm short to ground on the orange 3.3v line. Hope this helps.

[R_J]

Re: Delta DPS-160QP Power Supply

C101 & C301 seem to be across the transformer winding via some low Ω resistors. Have you repaired the standby circuit?

[CapLeaker]

Re: Delta DPS-160QP Power Supply

50 ohm to GND on a low voltage rail? Work the PSU in reverse (from the connector backwards) you probably find something like two 100 ohm loading resistors in parallel to gnd. Those should be right near the output caps and the cable harness.

[John McGivern]

Re: Delta DPS-160QP Power Supply

No I don’t have the replacement chip yet.

[R_J]

Re: Delta DPS-160QP Power Supply

No I don't have the replacement chip yet.

It is likely that the only problem is with the standby circuit, The main part of the power supply is likely ok.

[John McGivern]

Re: Delta DPS-160QP Power Supply

R_J Thanks for your reply, as previously mentioned I was hoping to pinpoint the exact problem ie component. I am trying to learn the what and why something has failed and how the circuit works, being a novice and old doesn’t help. I am not making excuses and I am basically sacrificing this psu with the intention of learning. If a fuse blows I have learned nothing. Many thanks again.

[stj]

Re: Delta DPS-160QP Power Supply

it failed probably because TNY chips are shit and probably cant disipate enough heat.

[R_J]

Re: Delta DPS-160QP Power Supply

R_J Thanks for your reply, as previously mentioned I was hoping to pinpoint the exact problem ie component. I am trying to learn the what and why something has failed and how the circuit works, being a novice and old doesn’t help. I am not making excuses and I am basically sacrificing this psu with the intention of learning. If a fuse blows I have learned nothing. Many thanks again.

If you do not have the standby voltage, then the exact component would be the tnyxxx ic and likely the small electrolytic next to it on it's VCC supply line.
Being the standby circuit, it is ON all the time so the vcc capacitor dries out.
Without the standby voltage the rest of the power supply can not operate as it also supplies voltage to the main smps section.

[John McGivern]

Re: Delta DPS-160QP Power Supply

Ok lads I’ll get back to you when I get the new chip may be a while, many thanks.

[John McGivern]

Re: Delta DPS-160QP Power Supply

Update, thank you to everyone for the help and advice to repair this PSU.
I managed to buy a second hand replacement rather than trying to buy separate components.
So PC now working after many hours on MB, on POST I was getting 1 short beep 1 long beep continuously. After several attempts I sprayed RAM positions and sticks with cleaner and the PC eventually booted. So many thanks to all. Merry Xmas and Happy New Year.