Why will my PC only boot after a CMOS refresh?

Discussion in 'PC Hardware' started by alexthe_dragon, Jul 22, 2015.

  1. alexthe_dragon

    alexthe_dragon MDL Novice

    Jul 22, 2015
    Hey all,

    I'm having trouble with my PC. An external HDD was pulled out while the computer was booting up and after that the PC won't start. Three beeps sound, and then the computer instantly freezes. I can't boot from a disk or USB, nor can I flash the BIOS as the computer freezes as soon as it starts and won't respond to any commands (like F6 for Boot Menu for example). There is a horizontal green bar at the top of the screen and it sits there without changing.

    I opened up the shell and reset the CMOS manually (tried both the switch and removing the battery, both gave the same result) and it gives me one good start, and after that it is fine. I can access my Windows or Linux partitions no problem and everything is completely functional. The only issue is when I want to restart the computer it does it again. Which means I have to open the shell, manually reset the BIOS and start all over again. Argh.

    Does anyone know a fix? I wanted to flash the BIOS but can't do it as I can't access the boot menu when I restart, nor can I find a way of re-installing it from Windows.

    My specs are as follows:

    Processor: Intel Xeon E3 1240 V2 @ 3.40GHz
    Motherboard: Intel Corporation S1200BTL
    Bios Version/Date: Intel Corp. S1200BT.86B.02.00.0035.030220120927, 2/03/2012

    PS: I am a mega n00b when it comes to this stuff, mainly working things out as I go, so please go easy.
  2. EFA11

    EFA11 Avatar Guru

    Oct 7, 2010
    For that intel board, I believe the 3 beeps are RAM. Pull your ram and check it, clean the tips gently and replace them. Make sure they are seated well into their slots.

    IF that fails, IMO your ram is toast, If I am on the right track.
  3. LatinMcG

    LatinMcG Bios Borker

    Feb 27, 2011
  4. alexthe_dragon

    alexthe_dragon MDL Novice

    Jul 22, 2015
    Thanks for replying. I had it wrong though (sorry), it is actually 2 Beeps (pause) 3 Beeps. Do you know what that could signify?
  5. Michaela Joy

    Michaela Joy MDL Crazy Lady

    Jul 26, 2012
    Stop hovering to collapse... Click to collapse... Hover to expand... Click to expand...
  6. November_Zulu

    November_Zulu MDL Junior Member

    Jul 21, 2015
    A poor quality power supply will under-deliver necessary voltage to the RAM (as well as CPU). Physically pull RAM from motherboard and note it's specs (make, model, etc...), then research what voltage that RAM needs to operate at. Then check BIOS to see what voltage it claims it is delivering. Then install software like SpeedFan (or whatever is current, my tech is dated for this kind of thing) and find out what the voltage actually is.

    Post specs of power supply for public evaluation and possible mockery and derision. Also a report from software like SpeedFan would be useful to see what the voltages and temps are like at idle and with CPU/RAM under heavy load (play a couple videos or something).

    TBH any kind of hardware issue can cause oddball problems like this. How old is the motherboard? It's possible (outside chance) the CMOS battery is low/marginal and your CMOS is getting corrupted due to low CMOS battery power. But these are the easiest and most likely causes, i.e. power supply, RAM, CMOS battery.

    Even IF (I really shouldn't say this but), even IF the power supply is a POS, it's possible to make it deliver adequate voltage by manually tweaking the voltage delivered to the RAM via BIOS settings. Example let's say your RAM needs 1.8 volts, and the BIOS says it's got 1.8 volts but SpeedFan says it's only 1.65. You can boost the voltage to the RAM by .1 or .2 volts (no more) and not risk overheating and burning up the RAM, however that's on the list of possible consequences. Assuming the PSU is a POS (safe bet), running constantly with a substandard power supply is highly dangerous as some or even all of these things can be suddenly cratered by a poor power supply:

    power supply
    Video Card

    If you dig around online, you can find numerous horror stories from people that have had this happen. Back in the day when I was an online Tech, I would give people the warning above and they would assume the advice was worth what they paid for it. Then, 2 months later, they'd post back complaining that their computer was now a brick and long story short, I know of several situations where multiple components were killed-off by a bad PSU. Ask around. Anyone that knows anything will tell you that the single most important component of any system is the Power Supply.
  7. LatinMcG

    LatinMcG Bios Borker

    Feb 27, 2011
    ^ partially agree.. my friend had intel board not want to shutdown or turn on properly from first day out of box. i never figured out exactly the issue.. seems its intel made board issue and junk power supplies.
    IDG45 or something model.
  8. xhsiao

    xhsiao MDL Novice

    Aug 25, 2010
    I would check the 3V lithium CMOS battery first. Take it out and measure it. The open circuit voltage should be about 3V. Replace it if it's too low.