Problem with delta dps-700fb

[370forlife]

Ok, so a problem has sprung up with it. Sometimes, when trying to start my computer, it won't. I will hit the power button and the power light and hd light just stay solid, fan on video card spins up to full speed and stays there, and no post. Resetting usually does no good, I have to hold the power button until it turns off, unplug the psu, hit the power button, replug it in and hit the power button. Then repeat until it finally starts.

Strange thing is it does it over time. For the first 10 or so start ups it works like a charm, then it will do it once, then start up, then twice or three times, then it refuses to no matter how many times I try. I put in my AcBel 550W, and it starts right up every time, never had a problem. Well, I am planning on getting another 9800gt for my 'puter and the delta is the only one I have with 2 pci-connectors (besides the logisys 575W,) or if I get a gtx260 or 280.

The motherboard is a Biostar Tpower N750 (with all UCC solid caps), video card is a PNY 9800gt. Ram is 2x2gb OCZ DDR2-800.

Nothing is overclocked, overvolted, etc...

[POM_MJ]

Re: Problem with delta dps-700fb

Did you have check the PG signal?, many of Delta unit has no resister pull-up PG signal to +5V. (it's open collector O/P PG signal PSU for used with Server platform)

[370forlife]

Re: Problem with delta dps-700fb

The PG signal is the grey wire next to the 5vsb wire, correct? If so, I'm getting nothing on it. 5vsb reads 5.07v, and the PS-ON reads 4.41v.

[POM_MJ]

Re: Problem with delta dps-700fb

>>The PG signal is the grey wire next to the 5vsb wire, correct?
Yes.

>>If so, I'm getting nothing on it. 5vsb reads 5.07v, and the PS-ON reads 4.41v.
Turn on by hit power button, the PS-ON should be near 0V and PG should go near 5.0V.
if PG is not there, might be open collector PG signal, try add a pull-up resister 1Kohm 1/4W between PG (gray) and +5V (any red)

[Toasty]

Re: Problem with delta dps-700fb

Not enough load. Remember mine wouldn't bench-test-start:

https://www.badcaps.net/forum/showthread.php?t=7928

I had loaded all the legs with various high-power, low ohm resistors. It would pulse voltages but still wouldn't start.

On a whim I tried loading the +5VSB with about 100mA and voilà!

Removed all the loads and tried loading each voltage individually.

Results:
It's necessary to load the +12V on any connector with about 400-500mA and the +5VSB with about 100mA. No other loads attached and it runs.

Experimentation shows:
Hard drive(s) won't do. Evidently the +12V connection doesn't present any load to the PSU initially.

3 - 80mm fans will do it. Start about 500mA, run 350mA.

Voltage Measurements:

+5.05VSB
+3.33V
+5.08V
+12.06
-12.0
+4.52PG (gray)

[Toasty]

Re: Problem with delta dps-700fb

Oh yeah, another item. The little sideboard/daughterboard with the PIC chip on it monitors all the voltages on the smaller "sense" wires coming back from the connectors.

Toast

[POM_MJ]

Re: Problem with delta dps-700fb

I think 370forlife's Delta unit has different problem, look like it was started but the system didn't POST.
sorry, if I misunderstand reading.

[370forlife]

Re: Problem with delta dps-700fb

Yes, the system turns on and everything but no post. Problem goes away with the AcBel.

This delta was in my friend's computer and it did the same thing, traded my 750W HEC Zephyr for it (he he he) and now it's doing it with my computer.

[ratdude747]

Re: Problem with delta dps-700fb

you gave someone an HEC? shame on you! (sarcasm)

[Toasty]

Re: Problem with delta dps-700fb

Seems the missing PG will do it from what you have reported. See the voltages I reported with just the 12v and 5vsb loaded and see if you get that (4.5v).

Also, the PS-ON doesn't seem low enough. Try jumpering that direct or thru switch.

[370forlife]

Re: Problem with delta dps-700fb

I can't seem to get enough of a load on it standing alone.

[370forlife]

Re: Problem with delta dps-700fb

whoops should have read your post in your thread about this psu toasty.

I got it running with just a .17A fan on running off the 5vsb, and a .52A fan running off the 12v on the cpu connector fired it right up. PG signal on the grey wire measure 4.47v. Disappears when powered off.

[Toasty]

Re: Problem with delta dps-700fb

This -was- working and then stopped working, correct?

Compare the voltages between the 2 PSU's that you get from the mobo plug with it plugged into the system.

PCBONEZ said in the other (my) PSU thread, and POM_MJ said here, that these are -server- PSU's. Any chance there's a signal that a server mobo would generate that the supply is looking for and not receiving from your mobo?

The PG signal is specified (ATX) at +5v, but can vary ±1v in practice.

Try POM_MJ's suggestion. Stuff a 1k resistor into the back of the mobo plug from +5v line to PG line.

Is the white "P2" plug connected to anything? That has a "sense" line (yellow) connected to it on pin 8.

Toast

[370forlife]

Re: Problem with delta dps-700fb

The thing is it works most of the time, powers up my computer no problem, but after a while is when it starts doing it. Like right now I am on the said computer with the said power supply in it.

Is the white "P2" plug connected to anything? That has a "sense" line (yellow) connected to it on pin 8.

Yes, it is connected to the motherboard's 8pin cpu connector.

[i4004]

Re: Problem with delta dps-700fb

...redundant post on my behalf trimmed...
it indeed is psu malfunction as pom and i thought.

[370forlife]

Re: Problem with delta dps-700fb

I don't know.

Ok, so a problem has sprung up with it. Sometimes, when trying to start my computer, it won't. I will hit the power button and the power light and hd light just stay solid, fan on video card spins up to full speed and stays there, and no post. Resetting usually does no good, I have to hold the power button until it turns off, unplug the psu, hit the power button, replug it in and hit the power button. Then repeat until it finally starts. Strange thing is it does it over time. For the first 10 or so start ups it works like a charm, then it will do it once, then start up, then twice or three times, then it refuses to no matter how many times I try. I put in my AcBel 550W, and it starts right up every time, never had a problem. Well, I am planning on getting another 9800gt for my 'puter and the delta is the only one I have with 2 pci-connectors (besides the logisys 575W,) or if I get a gtx260 or 280. The motherboard is a Biostar Tpower N750 (with all UCC solid caps), video card is a PNY 9800gt. Ram is 2x2gb OCZ DDR2-800. Nothing is overclocked, overvolted, etc...

It did the same exact thing on my friend's EVGA something-or-other board. Worked for like the first 10 times, then started going wonky.

[Toasty]

Re: Problem with delta dps-700fb

When it does it, how's the PG voltage?

[i4004]

Re: Problem with delta dps-700fb

forget it 370, toasty was causing unreasonable stir, as usual.

sorry for you taking the flak because of his rubbish.

notice that in that other thread i said your problem and his were not simillar:
https://www.badcaps.net/forum/showpo...1&postcount=10

carry on...

[370forlife]

Re: Problem with delta dps-700fb

When it does it, how's the PG voltage?

4.61. Reads 4.61 when it works too. When it first starts up it spikes to about 5.10. Doing something new now. When I pull the psu plug out, wait until the power diagnostic led on the board goes out, then plug it back in, it will fire up for a second, then shut off. Then when I hit the power button, it does the little problem. (though I think the turning on for a second and shutting off is just the board doing something...)

I was looking at the diagnostic LED's on the board, and they stop at VGA, meaning the VGA light dosen't light up. Strange. Same problem on my friend's board with a gtx260 on this psu. Doesn't ever do it with the AcBel.

[Toasty]

Re: Problem with delta dps-700fb

Have you tried switching PCI connectors? Maybe it -needs- both connected? If these PSU's were built for a specific server setup, then that PIC chip is likely programmed to detect all of these connections and may be the culprit.