Solved Power supply problems?

[frogmaster]

I own a Dell Optiplex 745, minitower, and I do not understand what my problem is. It has a standard, 350 watt power supply with a 24 pin connector and I tried to replace it with a new ATX 750 watt power supply with the same 24 pin connector. I plugged in everything properly (I triple checked) and every time I try to start the computer, the Dell loading screen pops up as usual, but it stops loading and the computer makes a rapid beeping sound and stays like that (with the loading screen frozen and computer beeping) till you turn it off. Is there a way for me to tell if the power supply is bad or if it's not compatible with my computer..?

 

[linnemeyerhere]

Did you plug in the mobo 4 or 8 pin 12v connector?
http://www.brighthub.com/computing/hardware/articles/26362.aspx

 

[PooMan UK]

Hiya pal

Continuous long beeps normally means your Graphics card is not inserted properly or you haven't connected the power supply to it (if needed)

Continuous short beeps normally means a power error

Continuous short to medium beeps can represent a memory problem (Try running a single stick in each of the slots and make sure they are seated properly)

Hope this helps a bit

 

[TVeblen]

Is there a pattern to the beeps?

Here is a list of typical Dell beep codes:
Documentation
Down towards the bottom of the list.

 

[frogmaster]

The beeps were continuous and short; I am almost completely positive they signified a power error. I plugged in everything that my computer had previously connected, and could find no additional ports to connect on the motherboard or any other internal devices.

 

[linnemeyerhere]

What is the make and model of this PSU?

 

[frogmaster]

The new one is a FSP750-80EPN 750 Watt ATX Power Supply. FSP FSP750-80EPN 750 Watt ATX Power Supply

 

[TVeblen]

That is a very 'inexpensive' power supply. The likelihood that it is defective has risen.

There could also be a short circuit somewhere. You want to visually inspect the board and the connections for any damage/defects.

If you have a multimeter you can test the power supply's connectors for proper voltage, particularly 12v on the yellow lines.

Why did you decide to replace the power supply in the first place? To solve a problem? What was the problem?

 

[FaberTech]

A long shot, but I have had to reset the cmos before to get a new power supply to work. give it a try.

 

[frogmaster]

I am going to try what you said, FaberTech, and with any amount of luck it will work. I do own a multimeter and will try to test the thing for short circuits too. A couple weeks back I bought a graphics card that required a greater power supply than I had in my machine, so the best option was to upgrade the supply instead of buying another card. I figured it would be better for the electric bill anyway.

 

[FaberTech]

Just make sure the video card doesn't need extra six pin plugs. If it does, you should hook them up. Mine requires two six pin plugs. also, a lot of motherboards require the extra 4 -8 pin be hooked up near the processor. I have made the mistake of not hooking it up before. :/ Also, unless you live in Europe, make sure your Power Supply switch on the back is at 115V.

 

[linnemeyerhere]

Well I hope that the PSU isn't bad from the get go and also in a perfect world we would have directed you to a host of top quality brands which would outperform this unit with higher ratings and also have either a semi or total modular design which allows you to only use the connectors you need and no more. So lets hope the PSU is faulty and then you just have to RMA it. If they give you grief then try to work your money back and then hit us up so we can suggest quality options that you can carry forward to you next several builds.

 

[Al Fairclough]

I believe that Dell uses their own proprietary pin-out pattern for their PSU on that model. That being the case, you are stuck with a Dell PSU.

 

[frogmaster]

Well, I fixed the problem myself. Guess I just got lucky; I just plugged in everything, turned it on, and it worked.

 

[Al Fairclough]

Well, I fixed the problem myself. Guess I just got lucky; I just plugged in everything, turned it on, and it worked.

Outstanding! Now, go buy a lottery ticket.

 

[linnemeyerhere]

YEAH! It's always something silly like you thought the connectors clicked but it wasn't fully seated. Good work, enjoy and post some pictures when you get a chance.