Optiplex 745 will not boot: two beeps and 1-2-3 lights on

Hi all,

I pulled out my old Dell Optiplex 745 to try and put it to some use and am having some trouble getting it to boot up. At post, the system will give two short beeps and display lights 1-2-3 solid green, 4 is off. Video does not display.

I have tried many different things:
1. Stripping down the components to just processor and power supply. Upon power on, it gave off a different boot sequence to signify no memory.
2. I put in the memory (no HDD, video card, cd-rom drive connected) and get to the same point that I get to with all of those components plugged in -- 1-2-3 lights on and two quick beeps.
3. I have also reseated each of the two sticks of ram (individually) into each of the four slots.
4. I have replaced the system battery
5. I have tried a different (confirmed working) hard drive

When connected, the hard drive spins and other fans turns on so I'm guessing it isn't the power supply.

Dell's diagnostics guide suggests "Other failure" for 1-2-3 and to check that all cables are properly connected. I have reseated the memory, video card, hard drive connectors, power supply connectors,and dvd-rom connectors. No luck. Same symptoms.

Would it even get to this point if it was a processor or motherboard issue? I'm stumped... Help please!
6 answers Last reply
More about optiplex boot beeps lights
  1. From http://phubner.eng.ua.edu/Files/Optiplex%20745/trouble.htm, these are my symptoms:

    System Lights
    Your power button light and hard-drive light may indicate a computer problem.

    Solid green and a beep code during POST - A problem was detected while the BIOS was executing. - See Beep Codes for instructions on diagnosing the beep code. Also, check the diagnostic lights to see if the specific problem is identified (see Diagnostic Lights).

    Diagnostic Lights
    To help you troubleshoot a problem, your computer has four lights labeled "1," "2," "3," and "4" on the front or back panel. The lights can be off or green. When the computer starts normally, the patterns or codes on the lights change as the boot process completes.

    1-2-3 (on) 4 (off)
    A failure has occurred. This pattern also displays when you enter system setup (see Entering System Setup) and may not indicate a problem.

    Ensure that the cables are properly connected to the system board from the hard drive, CD drive, and DVD drive.
    Check the computer message that appears on your monitor screen.
    If the problem persists, contact Dell (see Contacting Dell).

    Beep Codes
    Your computer might emit a series of beeps during start-up if the monitor cannot display errors or problems. This series of beeps, called a beep code, identifies a problem. One possible beep code (code 1-3-1) consists of one beep, a burst of three beeps, and then one beep. This beep code tells you that the computer encountered a memory problem.

    Unfortunately, my beep code (1-1) is not listed here. Perhaps two beeps is normal?
  2. Just for the heck of it, I removed the heatsink and processor to check for bent pins. Looks good. I reapplied thermal paste and tried to power up... Same symptoms.
  3. So... I was curious to why video wasn't working at all or showing any errors if it got to POST. This PC uses one of those proprietary Dell connectors to the video card, which then connects to DVI. I rechecked the pins on that sucker and saw that a few were bent.

    I straightened them out and now I'm getting video out. It is getting past the BIOS and can you believe it, the error I was getting this whole time was a "Floppy not detected, press F1 to continue" message. Really? *facepalm*

    Attempting to boot an image up now...
  4. Hello,
    Not trying to hijack this thread but this is exactly the same problem i am having except i don't thik the solution applies as the video card is built in to the motherboard (http://www.ebay.com/itm/Dell-Optiplex-745-USFF-Ultra-Small-Motherboard-GW726-/140527524113).
    This problem occured on a computer used for a point of sale system. The computer worked fine untill 2 days ago and when i tried to boot the system there was no video at all.
    As stated in the above post, the fans and hard drive appear to be opperating normaly and the only clue i have so far is the lights on the back showing only 1-2-3 "other failure".
    This point of sale system is the only one i have in the store and the store is located in northern ontario where parts are not easily obtainable.
    Any help to diagnose this would be greatly appreciated ora way that i could get this box to boot to buy some time untill i can get to a location to puchse the needed parts.
    Thanks in advance
  5. I had the same issue. I re-seated the memory modules and all was well. Its always a good idea with intermittent power up issues to check all connections and re-seating components. Hope this helps
  6. It is a 6.3v 1800 UF Capacitor located about 1 1/2 inches below the integrated graphics heat sink, guaranteed. It will be puffed up, and probably black on the end.
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