Question POST issue after installing CPU ?

Jan 17, 2023
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Hello All

Thanks for letting me join the forum. I've used this site for guides and to solve issues and its been a great help, However im having an issue with a PC that i am unable to figure out

So, my work had some old PCs they were going to throw out. Seeing it as a waste i aquired two of them for my kids to use for homework etc. I then started to find parts that would be compatible to make them perform better and they can play some games on them also.

Both PCs are HP 500B MT ( i know couple of dinosaurs!) The first one i upgraded fine and it works perfectly, the second one is having a POST issue on startup even though both pcs/upgrades are the same
below are the upgrades to both PCs
KINGSTON SSD HARD DRIVE
GeForce GT710 Graphics card
intel core2quad Q8400 CPU

one pc works totally fine, the second one fails to start once i changed the old cpu to the core2 quad one and then gives me the one short beep and one long beep on startup.
ive checked the Ram seating, put the old CPU back in and it works. I even put the Q8400 from the other pc i upgraded into this one as i know that one works but still the same issue

The only difference i can make is that the 1st pc runs the Palit gt710 where the troubled pc is on the Asus gt710

both pcs are on windows 10 64bit and are on the bios 6.05 (lastest i could find)

I did remove the CMOS battery (but only for 20seconds or so) and replaced with a new battery

im stumped on this one, and i'm hoping someone could help point me in the right direction

Regards

Tom
 
You are fortunate(for diagnostics) to have two machines to work with.

Here are the beep diagnostic codes.
One short and one long indicates a ram error:
https://www.manualslib.com/manual/370854/Hp-500b-Microtower-Pc.html?page=69
Put the working cpu in and check the ram.
Run memtest86 or memtest86+
They boot from a usb stick and do not use windows.
You can download them here:
If you can run a full pass with NO errors, your ram should be ok.

Running several more passes will sometimes uncover an issue, but it takes more time.
Probably not worth it unless you really suspect a ram issue.

Possibly the asus710 has a problem.
Does the working pc do ok with the asus card installed?

Do you have a monitor that can accept the vga output that the motherboard provides>
 
Jan 17, 2023
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Hi geofelt,

thankyou for the reply, i will try the memtest tonight.

The Asus GT710 was installed and I have been using for a few weeks with no issues before i put in the upgraded CPU. I have not used the Asus card in the PC that is working fine, i think that may be a good idea to swap them over as the drivers for the cards are on both PCs, thanks for that 🆒


I am able to use the VGA output on the motherboard to a monitor if required.

Regards

Tom
 
I like integrated graphics to help identify discrete graphics issues.

One thing to check is the socket pins. They are all too easy to damage if you do not drop the cpu incleanly. Smooshing it around will damage pins.
One of the common symptoms is ram related such as borked slots or no dual channel.
Bent pins can often be fixes with a needle.
 
Jan 17, 2023
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Hi again

so i may of possibly made things better or worse! I was never 100% sure if i reset the cmos properly so i took out the battery for about 5 minutes. once done i turned the PC on and the beeps have gone but i get no display with the Q8400, also the power button did not light up as normal 😁. So i put the original CPU back in, the power button lit up blue, no beeps but now also no display again, At this point i had ran out of thermal compound and decided to quit before i really make a mess and ask the pro's!

Regards

Tom
 

Karadjgne

Titan
Ambassador
I even put the Q8400 from the other pc i upgraded into this one as i know that one works but still the same issue

So you took the questionable cpu and stuck it in the working pc or you took the good cpu and stuck it in the failing pc?

If the good cpu still failed in the non-working pc, and still no display, you most likely have a bad motherboard. Not surprising given its age, caps go bad.
 
Jan 17, 2023
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Hi Karadjgne

Thanks for the reply, I think you may be right, luckily these pc's were free and there is one more kicking about at work, gonna give that one a go with the parts i already have and hope that that one goes better

Regards

Tom