Hi everybody, I'd like to put my years of experience troubleshooting/fixing computers at your service (and for your sticky consideration). As I mentioned in my "Swedish Fish Theory"
thread I'm a former Geek Squad agent. I was the guy in the back fixing all the computers who's face you didn't see unless you had a really technical question that could stump one of the guys on the front counter (all of whom I trained). I worked on up to 40 computers at a time (I wired the work area myself), and we checked in ~8-20 computers on an average day - they were done on average in 1.4 days when I was a full timer (we only had 1 other tech, whom I also trained)... needless to say I fixed a few computers in my 4 years there. It was a good job to get through college on, and I learned/found/invented a couple VERY useful tricks that I haven't ever seen posted about for diagnosing "dead" desktops.A few notes:
--This works for both AMD and Intel motherboards, but I posted it here as all my PCs are Intel and I can only put it in one place - the fix is universal though.
--Yes, I've had times where a motherboard smelled burnt, but it was still a bad CPU and the motherboard worked.
--I've seen DVD drives stop a computer from POSTing.
--I've seen a failed PS/2 keyboard make a computer not POST.
--The PG signal is still pretty widely used on motherboards. PSU testers won't fail it every time, but if even it fails ONCE out of 20 tries, it's almost definitely a bad PSU.
--The voltages on the PSU tester I linked aren't perfect, but they're pretty close. It passing the PSU tester just means the PSU is "good enough" to get the motherboard through POST (the voltages can be unstable under load), but if it fails it is definitely bad. I ignored high voltages on it once and lost a motherboard to that PSU dying 2 days later.
--Booting a motherboard with the BIOS battery out won't damage it, but it will erase all your BIOS settings and in a few RARE cases may reflash it back to what the board shipped with (seen this maybe 20 times total). This is significant if you're using a very new CPU on an older board, keep a copy of the appropriate BIOS handy as you may need to re-flash your BIOS.Places the error code is normal according to the manual (incomplete list):
--Gigabyte P45, P55, P67, x58 - This as the last step of POST to show a boot attempt is made (Thanks to kiwiasian)Places it staying there is a problem verified from the manuals (incomplete list):
--MSI x58 - This is the CPU and power check on boot (hanging here means it can't pass this check)
--ASUS x58, P67, Z68 - Reserved error (according to tech support it's a short)
--ASRock x58, P67, Z68 - Reserved error (same BIOS as ASUS, asuming it's the same error)
--EVGA all chipsets - Unlisted in their documentation (I've heard EVGA techs call it "Fault Found" and that it's a short)
--Gigabyte x79 - Reserved errorTools (a very short list):
--A PSU tester - I use this one.
It's reliable, gives you the unloaded
voltages of every rail, and checks the "Power Good" signal from the PSU. If you don't have a PSU tester, then you need a spare PSU that you know works. One of these two is a MUST for fixing/testing "no POST" or FF situations
--A small flat blade screw driver (for removing the BIOS battery) or something equivalent - I usually use my pocket knife.
Firstly, if you're computer beeps or gives any other error code, look it up and fix it accordingly, the guide below is for the FF error code or if the computer won't POST at all.The dreaded "FF" POST code, or no POST at all
(this fix is best done outside a case to ensure the case isn't shorting the motherboard):1
) If you know what burnt electronics smell like, then smell your motherboard. I'm not joking. Specifically around the VREG (left/above the socket), Southbridge (below the socket) and Chipset (right of the PCI slots) areas. If you smell burnt electronics, keep that in mind if you hit step (7b) below as that'll means its the motherboard 99.9% of the time.2
) Test the PSU with the tester, if it's not beeping/blinking at you then it's ok (if you're using the one I linked). Unplug and re-plug the 24-pin connection several times. Keep an eye on the "PG" and see if it ever reports 0ms or 999ms as this means it's a bad PSU (since this is unloaded it won't fail the PSU tester every time even though it will fail the motherboard every time). If you don't have the PSU tester, swap in your known-good PSU.3
) With the PSU verified to be good, plug in ONLY the power to the motherboard (20+4-pin and 4/8-pin CPU power, but NOT
the 4-pin molex connection if it has one). Disconnect EVERYTHING
else from power (hard drives, DVD drives, etc).4
) Remove all
RAM. Remove all
GPUs. Remove all
other PCI/PCI-e cards. Unplug all
the cables (including SATA, IDE, FDD, SAS, USB, Firewire, HD Audio, and all the switches but the power switch) from the motherboard. You should have just your MoBo, CPU, HSF, PSU and a power switch connected right now. Disconnect EVERYTHING
from the front and back panels of the computer, including your mouse and keyboard.
4a) if your computer does NOTHING when you hit the power button, plug the reset switch into the power switch pins on the motherboard and use the reset button in case the power button has gone bad - yes, it happens, no it won't damage anything.
) Remove the BIOS battery and leave it out until you're told to put it back in.6
) Power on the computer. If it beeps or gives a POST code other than FF then go to (7a) below, if not check out (7b)7a
) If it beeps at you, or gives any POST code other than FF then turn it back off. Leave the BIOS battery out.
You will now add in 1 piece of hardware, power it on, check if it POSTs (and gives any error other than FF), if it does, turn it back off and add the next component. Start with RAM, one stick at a time, then GPUs, one at a time, then other expansion cards, finally HDDs/DVD drives - rebooting between each and every part.8a
) If it starts giving an FF code or stops POSTing all together then the last component you added is bad.9a
) If it doesn't give a FF error code and is still POSTing with all your hardware back in, shut it down again, put the BIOS battery back in and power back on one more time. If it gives an FF code now, replace your BIOS battery.10a
) If it works with everything back in, then your motherboard lives to fight another day.7b
) If it still POSTs as FF or not at all in this condition remove the CPU, make sure the pins are intact, reseat the CPU and HSF and try it again. If it still posts FF you either have a bad motherboard (about 95% of the time or about 100% if you smelled burnt electronics in step 1) or a bad CPU (about a 5% chance).8b
) Swap in a known working motherboard if you have one to test the CPU is good, or bring in a spare CPU to test the motherboard with. Whichever part fails is the culprit, replace it and go again.