Defective PSU? Please help!

[Evenkeel]

Here's the situation:

I just finished assembling my build last night. I used a PC Power & Cooling Silencer 750 Quad. Motherboard is Intel DX38BT, CPU is Intel QX9650. Other components connected at the time were one SATA II Seagate 750 GB HD, and one Samsung SATA DVD burner.

I connected up all the connectors: the three to the motherboard (big 24-pin, 8-pin CPU, and 4-pin molex for the PCI bus), one SATA power each to the HD and the burner. All case headers were connected (power switch, HD LED, etc.).

My current system, w/a 510watt PSU, is plugged into an APC RS1200 (1200 watt) Back-UPS. I unplugged it, plugged in the new system w/the PC Power 750watt PSU, and flipped the switch.

Immediately, my Back-UPS started screeching, and the "Overload" light lit up. I shut off the new system, quadruple-checked all my connections, and tried again. This time, nothing. No "overload" warning, no nothing.

The first time I started, as best I can recall (having been distracted by the Back-UPS alarm) no fans or HD activity was present even for that short period. The second time, definitely not.

I really dug in and started checking conections, and making sure the graphics card and RAM were seated. Everything checked out. Every connection was where it was supposed to be.

I went to PC Power's site, and they have this troubleshooting advice. I followed each step to the letter, including step #6: shorting between the green and black wires on the 24-pin connector. The PSU fan did not come on.

This seems to indicate a bad PSU. But there are two odd things I want to note: one, when the connectors were still plugged into the motherboard, the tiny green LED next to the 24-pin mobo connector was lit up when the PSU was turned on. Two, when I pressed the power switch on the computer case, the power-on LED blinked on and off, rather than coming on steadily.

So can a PSU be bad, and still supply some power? Enough to light up the 24-pin mobo LED, and make the power switch blink? And what does the power switch LED blinking indicate? (I'm sure it means something; I just don't know what.)

I had originally planned to order the PSU directly from PC Power, like I did last time. But they now have resellers listed on their web site, and one was Amazon, which is where I ordered from. It cost less, and no tax plus free two-day shipping. But it came in a huge box, w/hardly any packing, and now I wonder if it got bumped around so much that it ruined the PSU? Hard to believe; PC Power builds like a tank, but possible, I suppose.

I know most of you experienced guys have gone thru this--putting it all together and flipping the switch, only to discover some part was DOA. This is my first time, and I am crushed. But if it has to be one part, I'd rather it be the PSU, than the motherboard. Can you guys give me some guidance as to if it is indeed the PSU that is dead? (Make sure to read the troubleshooting steps I followed on PC Power's site, so you know what I did to test.) And if it is the PSU, I am sending it back to Amazon and ordering direct from PC Power this time--they actually know how to pack an electronic component.

 

[Quiksilver]

(big 24-pin, 6-pin CPU, and 4-pin molex for the PCI bus),

What...?
6 pin PCI-Express connector is for PCI-Express graphics cards (sometimes their 8 Pin as well)
The 4 Pin 12V connector is for CPU(sometimes these are 8 pin too).

So if you really did put it the way you said, that sounds to be your problem.

 

[DSF]

One obvious troubleshooting step would be to try the 510W power supply that you know is good, and see if it powers your system up.

 

[Evenkeel]

Originally posted by: Quiksilver

(big 24-pin, 6-pin CPU, and 4-pin molex for the PCI bus),

What...?
6 pin PCI-Express connector is for PCI-Express graphics cards (sometimes their 8 Pin as well)
The 4 Pin 12V connector is for CPU(sometimes these are 8 pin too).

So if you really did put it the way you said, that sounds to be your problem.

Sorry... meant 8-pin CPU connector. ("2x4 pin connector", as it reads in the Intel manual.) I corrected it in the OP.

 

[Evenkeel]

Originally posted by: DSF
One obvious troubleshooting step would be to try the 510W power supply that you know is good, and see if it powers your system up.

I did think of that, but I believe that the 510w PSU has a 4-pin CPU connector, and the motherboard specifically says, "Do not use the included 2 x 2 to 2 x 4 adapter when using an Intel® Pentium® processor Extreme Edition or other Intel processor that is not running at its default settings. Doing so may result in damage to the Desktop Board." While the BIOS is probably set at default settings for CPU, I won't know that until I can fire it up, and I can't fire it up until I have a working PSU... You get the idea. Not to mention having to tear down my working system to check this out.

Isnt' there any way to verify from my description, whether it's the PSU at fault?

 

[LOUISSSSS]

you should still be fine plugging in the 510 PCPC PSU and using only the 4pin cpu power... thats exactly what i'm doing with my motherboard fine now and i can even overclock.

 

[AmphibSailor]

Back-UPS started screeching, and the "Overload" light lit up.

This sounds like a short or you else the UPS cannot handle the 750 watt psu (probably not the case since you're not really loading the psu down). Check your motherboard mounts.

 

[rgallant]

Originally posted by: Evenkeel
Here's the situation:

I just finished assembling my build last night. I used a PC Power & Cooling Silencer 750 Quad. Motherboard is Intel DX38BT, CPU is Intel QX9650. Other components connected at the time were one SATA II Seagate 750 GB HD, and one Samsung SATA DVD burner.

I connected up all the connectors: the three to the motherboard (big 24-pin, 8-pin CPU, and 4-pin molex for the PCI bus), one SATA power each to the HD and the burner. All case headers were connected (power switch, HD LED, etc.).

My current system, w/a 510watt PSU, is plugged into an APC RS1200 (1200 watt) Back-UPS. I unplugged it, plugged in the new system w/the PC Power 750watt PSU, and flipped the switch.

Immediately, my Back-UPS started screeching, and the "Overload" light lit up. I shut off the new system, quadruple-checked all my connections, and tried again. This time, nothing. No "overload" warning, no nothing.

The first time I started, as best I can recall (having been distracted by the Back-UPS alarm) no fans or HD activity was present even for that short period. The second time, definitely not.

I really dug in and started checking conections, and making sure the graphics card and RAM were seated. Everything checked out. Every connection was where it was supposed to be.

I went to PC Power's site, and they have this troubleshooting advice. I followed each step to the letter, including step #6: shorting between the green and black wires on the 24-pin connector. The PSU fan did not come on.

This seems to indicate a bad PSU. But there are two odd things I want to note: one, when the connectors were still plugged into the motherboard, the tiny green LED next to the 24-pin mobo connector was lit up when the PSU was turned on. Two, when I pressed the power switch on the computer case, the power-on LED blinked on and off, rather than coming on steadily.

So can a PSU be bad, and still supply some power? Enough to light up the 24-pin mobo LED, and make the power switch blink? And what does the power switch LED blinking indicate? (I'm sure it means something; I just don't know what.)

I had originally planned to order the PSU directly from PC Power, like I did last time. But they now have resellers listed on their web site, and one was Amazon, which is where I ordered from. It cost less, and no tax plus free two-day shipping. But it came in a huge box, w/hardly any packing, and now I wonder if it got bumped around so much that it ruined the PSU? Hard to believe; PC Power builds like a tank, but possible, I suppose.

I know most of you experienced guys have gone thru this--putting it all together and flipping the switch, only to discover some part was DOA. This is my first time, and I am crushed. But if it has to be one part, I'd rather it be the PSU, than the motherboard. Can you guys give me some guidance as to if it is indeed the PSU that is dead? (Make sure to read the troubleshooting steps I followed on PC Power's site, so you know what I did to test.) And if it is the PSU, I am sending it back to Amazon and ordering direct from PC Power this time--they actually know how to pack an electronic component.

-looks like your APC has this[Output Waveform Stepped approximation to a sinewave ] whatever that means.

-and might not like your new power supply,with my enermax there is a warning to only use a UPS with a sine wave only ! I have a 1000va smart APC with sine wave, but have not used it yet on my new P\S [nov-08] letting the system run stable before adding something new to the mix.
could have something to do with the active power correction, it can't adjust to a non sine wave ,just a guess

but did you need to reset the brecker in the UPS ?
and did you try not using the UPS ?
EDIT as I had something about multi rails but yours is a single

 

[Evenkeel]

Originally posted by: AmphibSailor

Back-UPS started screeching, and the "Overload" light lit up.

This sounds like a short or you else the UPS cannot handle the 750 watt psu (probably not the case since you're not really loading the psu down). Check your motherboard mounts.

I'm think short now too, as you're right, the UPS should easily have been able to handle the load--the old system is completely loaded down w/drives and draw on USB and Firewire ports, etc., so unplugging it and pluggin in the new system should have actually been a relief for it.

When you say to check my motherboard mounts, what exactly should I be looking for? Not trying to be a wiseguy; I really don't know what I'm supposed to look for. Each mounting screw is screwed down into each standoff as required, so what do I need to be aware of when checking this?

 

[Evenkeel]

Originally posted by: LOUISSSSS
you should still be fine plugging in the 510 PCPC PSU and using only the 4pin cpu power... thats exactly what i'm doing with my motherboard fine now and i can even overclock.

I'm not trying to argue with you, so please don't think that, but when I checked PC Power's site initially for what PSUs were compatible w/my motherboard and processor, the lowest wattage one it listed was the 750 Silencer. Plus, if my problem is a short in the new system, I could end up frying the old PSU as well (if indeed a short is the problem, which is looking more and more like it is). It's just that Intel's warnings make me nervous--I'm using both an Extreme system board, and and Extreme CPU, and they say not to use that 4-pin connector under those circumstances.

Do you really think I can get away w/using the 510w, or would it just be safer to get a new 750?

 

[Evenkeel]

Originally posted by: rgallant

-looks like your APC has this[Output Waveform Stepped approximation to a sinewave ] whatever that means.

-and might not like your new power supply,with my enermax there is a warning to only use a UPS with a sine wave only ! I have a 1000va smart APC with sine wave, but have not used it yet on my new P\S [nov-08] letting the system run stable before adding something new to the mix.
could have something to do with the active power correction, it can't adjust to a non sine wave ,just a guess

but did you need to reset the brecker in the UPS ?
and did you try not using the UPS ?
EDIT as I had something about multi rails but yours is a single

I did try to reset the breaker in the UPS, but believe it or not, it didn't trip--I plugged my old system back in right after, and it started right up, no problem. UPS is fine.

If you had a chance to follow the PC Power troubleshooting link above, you'll see that one of the steps is to plug the PSU directly into the wall--no UPS, surge protector, or line conditioner. I did do that step. Still nothing, other than the "standby" light next to the 24-pin connector on the mobo being lit.

 

[DSF]

Originally posted by: Evenkeel

Originally posted by: AmphibSailor

Back-UPS started screeching, and the "Overload" light lit up.

This sounds like a short or you else the UPS cannot handle the 750 watt psu (probably not the case since you're not really loading the psu down). Check your motherboard mounts.

I'm think short now too, as you're right, the UPS should easily have been able to handle the load--the old system is completely loaded down w/drives and draw on USB and Firewire ports, etc., so unplugging it and pluggin in the new system should have actually been a relief for it.

When you say to check my motherboard mounts, what exactly should I be looking for? Not trying to be a wiseguy; I really don't know what I'm supposed to look for. Each mounting screw is screwed down into each standoff as required, so what do I need to be aware of when checking this?

Make sure that you only have standoffs in the locations where you need them. If you have extra standoffs installed, remove them. (In other words, have a standoff under every screw hole on your motherboard, but don't have any others.)

Also double check and make sure nothing else could be shorting the motherboard to the tray, like a screw that might have fallen under the motherboard or some such.

 

[AmphibSailor]

Make sure that you only have standoffs in the locations where you need them. If you have extra standoffs installed, remove them. (In other words, have a standoff under every screw hole on your motherboard, but don't have any others.)

Also double check and make sure nothing else could be shorting the motherboard to the tray, like a screw that might have fallen under the motherboard or some such.

Ditto. Exactly what I would do. If you don't come up with any thing, then I would look at the case headers. I would unplug them all (before trying to apply pwr) and then plug one in with pwr off and then turn it on (start with the power switch). If no success, leave that one plugged in and choose another ... repeating until all are plugged into the board. Look at the mobo manual and make sure that you are plugging the connections into the correct pins on the mobo.

This is meticulous but should help discover the problem.

 

[Evenkeel]

Originally posted by: AmphibSailor

Make sure that you only have standoffs in the locations where you need them. If you have extra standoffs installed, remove them. (In other words, have a standoff under every screw hole on your motherboard, but don't have any others.)

Also double check and make sure nothing else could be shorting the motherboard to the tray, like a screw that might have fallen under the motherboard or some such.

Ditto. Exactly what I would do. If you don't come up with any thing, then I would look at the case headers. I would unplug them all (before trying to apply pwr) and then plug one in with pwr off and then turn it on (start with the power switch). If no success, leave that one plugged in and choose another ... repeating until all are plugged into the board. Look at the mobo manual and make sure that you are plugging the connections into the correct pins on the mobo.

This is meticulous but should help discover the problem.

I actually went all the way, and removed the motherboard from the case to bench-test it. So everything was disconnected. Only 24-pin main, 8-pin CPU, and 4-pin molex. Nothing happened, no startup. EIther the PSU, or the motherboard--or both--are DOA.

Also, all 10 standoffs were exactly where they were supposed to be, and the 10 mounting screws were properly screwed in thru the 10 mounting holes. No foreign metal under the board. No unusual contact w/the case. No burn marks anywhere on the mobo.

 

[rich168]

A UPS screeching means the PSU is drawing more power than what the UPS is rated.....

 

[AmphibSailor]

So everything was disconnected. Only 24-pin main, 8-pin CPU, and 4-pin molex. Nothing happened, no startup.

Don't you have to have the power switch connected to turn it on?