Trouble getting CPUs to work on a motherboard that should take them.

[DaftRonson]

I've got a HP G5345UK PC, and I'm trying to wring the last bit of performance out of it. It has a H-I41-uATX (Eton/EtonL) and HP's site says I should be able to use the following Socket 775 CPUs:

• Core 2 Quad Q8xx0/Q9xx0 (Yorkfield core) (95W)
• Core 2 Duo E8xx0 (Wolfdale core) (65W)
• Core 2 Duo E7xx0 (Wolfdale core) (65W)
• Pentium Dual Core E5xx0 (Wolfdale core) (65W)
• Celeron Dual Core E1xx0 (Conroe core) (65W)
• Celeron 4xx series (Conroe core) (35W)

However, I've tried an E8600 and a Q9550 and neither have worked. I get two short beeps, then a long one, and nothing on my monitor. I'm doing the usual, putting the fan on tight enough, using thermal paste etc - nothing.

Someone suggested that the motherboard couldn't handle 8GB with the CPU's slightly higher speed, but taking 4GB out didn't fix anything. I can put the old chip - an E5400 - back in and it works fine. I've also updated the BIOS and, since the bios settings are relatively locked down, there's no speed/CPU options to muck about with.

Has anyone got any ideas as to what could be up? I have a 500W power supply as well, so it doesn't seem like a power issue. I know it's an old PC but I hoped for that £25, I could double the PC's gaming performance.

 

[DaftRonson]

My mistake, it was one short beep then one long beep, as I discovered when I tried it again today. But I did try both integrated and add-on video card (I have a Nvidia card installed) and it made no difference.

 

[DaftRonson]

Unfortunately not. I got rid of the original memory ages ago. Though there's a UK chain that sells second hand memory - should I be looking for faster or slower memory? I currently have DDR3 10600 1333MHZ in there.. not sure of the timings, but both sticks are the same manufacturer.