Dell Dimension 4700: Replaced my motherboard, computer wont boot now

Discussion in 'PC Hardware' started by dictoresno, Oct 21, 2011.

  1. dictoresno

    dictoresno MDL Novice

    Jun 3, 2011
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    #1 dictoresno, Oct 21, 2011
    Last edited: Oct 21, 2011
    all of a sudden the other day, my computer shut down. i tried booting it up, and it did, however i had no peripherals. no monitor, no usb ports, no keyboard....etc. i got a new motherboard (oem dell replacement www(dot)ascendtech(dot)us/Itemdesc.asp?ic=MB4DELDIM4700&eq=&Tp= ). i just finished installing it and its the same as before....it boots up but still no input devices or monitor. all connections seem to be correct and everything was replaced properly. any ideas?

    its a Pentium 4, 3.0Ghz, 2.5GB RAM un modified BIOS.
     
  2. dictoresno

    dictoresno MDL Novice

    Jun 3, 2011
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    i edited my original post to be more specific. as far as i can tell, the computer itself is booting up normally as if nothing is wrong. it just wont light up the keyboard via PS/2 port, the monitor via VGA port or the mouse via USB. im sure i can get into bios, but i can see anything. i know the monitor and mouse work, i plugged them into my laptop.
     
  3. dictoresno

    dictoresno MDL Novice

    Jun 3, 2011
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    i have no access to another power supply. i am currently using 4 RAM sticks. 2x1GB and 2x256MB. no beeps at startup, it starts and runs just perfectly like any other day.....and for all i know is booting into windows.

    i cannot get into BIOS because i cannot see anything!!! no monitor output = running blind. and even if i could see, keyboard wont let me navigate.
     
  4. dictoresno

    dictoresno MDL Novice

    Jun 3, 2011
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    ok ill try that. i do get the keyboard to flash once on startup and flash again if i unplug and plug it in again. and now the dvd/cd drives each flash twice quickly over and over again.
     
  5. dictoresno

    dictoresno MDL Novice

    Jun 3, 2011
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    #5 dictoresno, Oct 21, 2011
    Last edited: Oct 21, 2011
    (OP)
    i was able to find CPU's on the same site i got my MB from. but they range from 2.8-3.6Ghz but all say they are a 775 socket. if i grab the 3.2 Ghz processor for $27, will that work with my original LGA775 board or do i need to be more specific and use the same exact one? how can i tell the CPU is bad??

    removing all of the RAM and booting does indeed generate a beeping error.
     
  6. R29k

    R29k MDL GLaDOS

    Feb 13, 2011
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    It cannot be the CPU acrsn or it would not post, assuming that it is posting :eek:
    @dictoresno How are you able to tell that it is booting up in the first place, you are being too vague, does the pc beep when you press the power button and try booting it ? Does your speaker work, DELL usually have post lights on the back of them does your PC have any ?
    If it is giving normal post beep then no dead cpu. I would then take out the board from the case and put it on table and use 1 stick of memory and hook it up to mouse, keyboard and monitor and try booting. You can bridge the power pins with a screw driver to boot it. If that doesn't work then try different memory stick but only use one at a time.
     
  7. dictoresno

    dictoresno MDL Novice

    Jun 3, 2011
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    #7 dictoresno, Oct 21, 2011
    Last edited: Oct 21, 2011
    (OP)
    here is the general breakdown......

    1.) i turn the computer on, both the power light and cpu light turn illuminate on the front of the tower...no beeps that i can hear. this all seems normal from what i can remember and seems good so far. the 1,2,3,4 lit numbers on the back of the tower above each corresponding USB port are lit, indicating power to them.

    2.) the keyboard num lock/scroll lock/caps lock lights illuminate, then go out. the optical mouse does NOT light at all (it would be lit by now)

    3.) monitor does not turn on or come out of sleep mode....its getting no signal from the computer.

    4.) after 30 seconds, the dvd/cdrom drives begin flashing twice quickly in 1 second intervals.

    5.) with the speakers on, i never hear it boot into windows, then again who is to say the sound card is even working

    if i remove the RAM and try to boot, the same as above happens, but the computer beeps over and over in error.
     
  8. dictoresno

    dictoresno MDL Novice

    Jun 3, 2011
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    btw i work nights and will be going to sleep shortly, so if i disappear, i will respond back as soon as i wake up. i really appreciate your feedback so far guys.
     
  9. dictoresno

    dictoresno MDL Novice

    Jun 3, 2011
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    ok i did as you stated. i booted up with only one RAM chip installed, and bam....computer booted. im gonna boot one by one and figure out which RAM chip is bad. and the error light i get on the back is ABCD. once fully booted, they are all green!!
     
  10. dictoresno

    dictoresno MDL Novice

    Jun 3, 2011
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    thanks again to both of you. i never would have thought this was the issue. i guess all the power outages recently and not having a UPC finally took its toll on the old RAM chips. thankfully, my aftermarket Crucial 2x1GB chips are ok, it was one or both of the OEM 256MB ones that failed.
     
  11. markedbyalantattoos

    markedbyalantattoos MDL Novice

    Jul 24, 2009
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    so was the old motherboard even bad?