Optiplex 745 BIOS POST failure[s]

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Optiplex 745 BIOS POST failure[s]

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This problem is associated with a Dell "Optiplex 745" running Windows Vista

The BIOS is: AMI 8.06 mode VEFI

Initial indications of the problem were [in order]:

A. Unattended random power on/off cycling

B. Random "no signal" messages on monitor

C. Occasionally a successful, short-lived boot to desktop could be achieved

Since I still had occasional access to the Setup program, I ensured all settings were correct, replaced the Battery and reset the clock

Subsequent actitity:

A. Partial POST runs with message: "memory not properly identified or being used - run F2 Setup"

B. No POST advance to point of getting video to the monitor

C. Hopeful attempts to "blindly" use F2 key are unsuccessful

Prior to further troubleshooting steps,  the diagnostic light/sound pattern is:  "1" green diagnostic light followed by a 1-3-2 beep sequence [this is the current status]!!

I went to the DELL Community Support site, searched for the light/beep information and was led to several "solutions" - the most relative being this:

Excerpt from DELL COMMUNITY item of 05-16-2011

......you've arrived at the point of having to return to 1975-style diagnostics and strip down the system. First unplug EVERY cord going into the system, including power, mouse, keyboard, network cable, any and all USB devices. Open the case and remove all expansion cards and all RAM sticks. Disconnect the power connectors and the cables from ALL drives

—floppy drive, hard drive, optical drive, media card reader if you got one of them. The goal is to arrive at a point where the only things left inside the box are the power supply, motherboard, and processor.

Once you're at that point, reconnect ONLY the power cord and turn the power on. The system should respond with a series of loud beeps, grouped 1-3-2, and show "1" on the front diagnostic lights. Next, power off and reinstall the RAM sticks, one at a time for preference, and restart. You should get "23" on the diag lights, meaning all the disk drives are missing (and so they are, since you unhooked them.)

Power off again, and connect the monitor to the computer (if this means you need to reinstall the video card, do that as well). Restart, and again you should get "23" on the diag lights as well as a message on the monitor about all the drives missing.

Power off, hook up the mouse and keyboard, and ONLY the floppy drive power and data cables. Restart, and you ought to get a message on the screen about "missing hard disk," which is normal. Next, power off, leave the floppy hooked up and repeat the process reconnecting the CD/DVD drive. On restart, it should complain again because it can't find a hard disk. Power off again, reconnect the hard drive, and restart. THIS time it ought to boot.

After that, reinstall any other expansion card that may be present one at a time, attach external devices one at a time and restart after each to see whether any of them are hanging the boot. If at ANY point during the system strip and rebuild the wheels come off, and you get a result other than what I described, make a note of the diag light codes and any onscreen messages, and call tech support.

 

SO I DID THE FOLLOWING:

1. Disconnected/removed Unplugged ALL devices internal/external including the four RAM sticks.

2. Reset the CMOS by temporarily using the Password jumper

3. At turn-on, the power light persistently goes steady green, the POST "initiates" displaying the "1" green diagnostic light followed by the 1-3-2 beep sequence.

In other words, I'm back to where I began!! I thought I'd post this forum request before either replacing the mother board or otherwise trashing the computer.

 

YOUR ADVICE AND ASSISTANCE IS MORE THAN WELCOME

Verified Answer
  • Hi Ron,

    I found and installed an exact DELL 745 replacement motherboard. Cleaned and re-applied thermal paste to the processor/fan and hooked it up!

    It booted right to the BIOS setup screen trying to seek the floppy drive. I changed the BIOS settings to delete the drive, set it for Fast Boot and reset the clock.

    Everything works fine - this case is closed!!

    Thanks, Bill

All Replies
  • Everything you said points to a memory issue. Have you tried installing the RAM modules one at a time in slot 1 (closest to CPU)?

    1. Power off, unplug
    2. Press/hold power button for ~15 sec
    3. Remove all RAM except the one in slot 1
    4. Remove motherboard battery
    5. Press/hold power button for ~30 sec
    6. Reinstall the battery (right-side-up!)
    7. See if it boots now with only mouse, monitor and keyboard connected
    8. Repeat the process, except swap all of the other modules into slot 1 until you identify a bad modiule
    9. If they all work in slot 1, repeat the process but this time add a second module to slot 2, etc. until you've reinstalled all of them or  identified a bad slot

     

    If this answers your question, please click  Yes  

    Ron

    Forum Member since 2004

    I am NOT a Dell employee

  • For ROHE,

    Thanks for your timely response.

    I followed your suggestions to the letter - results remain the same i.e. Power on - single beep [CDROM drive accessed?] then three beeps - two beeps coming to rest with a "steady green 1" diagnostic light.

    Question: Is this particular PC such that when the power cord is inserted, the system starts for a few seconds then momentarily shuts down before starting  again?

    Any other thoughts?

  • Bad POWER SUPPLY.

    RAM BAD DUE TO Improper voltage.

    Heatsink fan bad overheat shutdown.

    Report Unresolved Customer Service Issues here:

    Dell - Unresolved Customer Service Issues

    I do not work for Dell. I too am a user.

    The forum is primarily user to user, with Dell employees moderating.

  • but not for me

    For ROHE,

    Thanks for your timely response.

    I followed your suggestions to the letter - results remain the same i.e. Power on - single beep [CDROM drive accessed?] then three beeps - two beeps coming to rest with a "steady green 1" diagnostic light.

    Question: Is this particular PC such that when the power cord is inserted, the system starts for a few seconds then momentarily shuts down before starting  again?

    Any other thoughts?

    Are you saying none of the RAM works in slot 1? That might suggest a power supply issue, especially if it's turning itself on randomly.

    BIOS on most Dell PCs has an option about what to do when recovering from a power failure (eg you plug it back into the wall). So it will turn on very briefly to check BIOS to see if it's supposed to do nothing (and shut off again) or reboot.

    If this answers your question, please click  Yes  

    Ron

    Forum Member since 2004

    I am NOT a Dell employee

  • Hello again RHOE,

    Latest: 

    I took the suspect PC to a PC Parts & Service friend where I have occasion to get stuff from him.

    We used a known "good", working OptiPlex 745 to test the suspect PC power supply and It booted right to desktop in <3sec. Then we installed one of the RAM sticks from the suspect computer into the "good" computer. Again, the "good" computer booted right up!

    Then the "good" supply was installed into  suspect PC with the same problem trying to boot - as usual, the processer and power supply fans would start momentarily and stop.

    I suppose changing out the motherboard is next!!

    Stay tuned!!

  • It did cross my mind the motherboard failed, rather than the power supply, but I didn't want to make that leap without more info.

    You should try stripping this motherboard down to bare essentials (eg, disconnect all drives except boot hard drive, remove all PCI cards except video, etc) to see if there's some other problem before swapping motherboards. A number of dealers sell new/used/refurbished Dell motherboards so shop around, and there's always eBay.

    Good luck!

    If this answers your question, please click  Yes  

    Ron

    Forum Member since 2004

    I am NOT a Dell employee

  • Hi Ron,

    I found and installed an exact DELL 745 replacement motherboard. Cleaned and re-applied thermal paste to the processor/fan and hooked it up!

    It booted right to the BIOS setup screen trying to seek the floppy drive. I changed the BIOS settings to delete the drive, set it for Fast Boot and reset the clock.

    Everything works fine - this case is closed!!

    Thanks, Bill

  • Yes   Yes

    If this answers your question, please click  Yes  

    Ron

    Forum Member since 2004

    I am NOT a Dell employee