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optiplex 755 will not boot past the splash screen

twert007 asked
Medium Priority
Last Modified: 2012-05-09
Hi All,

I have a dell optiplex 755 and it will not boot past the Dell splash screen.  when it gets to the
first screen it stops . It dose not give an error code or any beep codes
I have :
1. Removed the Harddrive and Memory and it still dose the same thing

Watch Question

I recently ran into a similar problem with a Dell laptop.  The Dell startup screen would show about 3/4 done and then hang.  Hitting F2 before the lock up did not work.  I was able to solve the problem by removing all power (disconnect power adapter and remove battery) and letting it sit for a minute or so to let any residual power drain.  Your computer is a desktop, so try disconnecting the ac power cord for a minute or so.  (Just powering down is not sufficient since an ATX power supply is still providing 3.3V power to the motherboard even when the computer is off.)  If that doesn't work, try resetting the BIOS to their default; this usually involves temporarily setting a jumper on the motherboard.

When you unplug the PC from the wall, hit your power button to discharge any residual power left in the system.  

In addition to the above:
1. Verify that all of the power cables are properly connected and putting out the correct voltage.  You will need a multimeter to check the voltages.
2. Verify that the CPU is properly seated and that the CPU fan is snug against the CPU.  
3. Are all system fans running?  Are any of them running at full speed right before the shutdown (such as the CPU fan)?  If so, there could be a cooling problem.
4. Is there any visible damamge to the motherboard?  Leaking capacitors?
5. Have you tried replacing the memory and hard drive with known good components?
6. Finally, did you make any system changes immediately prior to the crash occuring?  A game install or OS update perhaps?
I'm assuming your not able to get into the BIOS?  (During startup, DEL key or F2, F8, F11?)

If you can remove the Dell splashscreen at startup (should be a BIOS option under Boot tab -> Quiet boot or Disable Diagnostics), you should be able to see in the POST what is going on.  

If so, go ahead and POST (no pun intended) those results and we might be able to figure it out from there.
Hitting escape during boot may show the POST as well.
Pls note the lED status (back side  of the cpu near power plug ) & mail to support.ap.dell.com & look your cpu cover ..ther is the phone number to contact dell...

Pls note the lED status (back side  of the cpu near power plug ) & mail to support.ap.dell.com & look your cpu cover ..ther is the phone number to contact dell...

Iain MacMillanIT Regional Manager - UK

some splash screens allow you to press ESC to see what's going on in the background, and likely hang at a certain point.  If you disconnect the hard drive and have taken the RAM out, if the board was working correctly, you should have got BEEP codes for the missing RAM.

If you didn't, then it sounds like the mainboard could have failed, or at least perhaps your CPU, which may be the reason you have the splash screen and nothing else.
That might be the MB issue so taht y i asked you contact DELL....

Most of the time I see this it's a USB device hanging the system up, or a BIOS setting. You might try disconnecting EVERYTHING from the back of the system (including power as recommended above) pull your CMOS battery for 30 seconds (or use the jumpers) then plug in Monitor and Power ONLY and see where it gets you. Hopefully you'll get a FDD seek error and date and time error, then just plug in the keyboard to get into BIOS and fix it. If it is POSTing after that try adding anything that you had connected one at a time (rebooting each time) and see if it starts hanging again.
IT Manager
You might also have a RAM failure - had this myself on a 755 a month back.  Remove each stick in turn and see if it boots nicely.  If you can get into the BIOS (it's F2 on Dells), the 755 has some Memory Diagnostics in there as well.  Also take note of the LEDs as stated above.  If it is the RAM, then Dell will probably just ship you a fresh stick.