my specs are:
intel core2duo E8500 3,16 ghz
2x1 gb apacer pc2-8500 CL5-5-5-15
seagate 640 gb
So, I bought an aditional 2x1 gb kit patriot PVS22G8500ELKN DDR2 5-5-5-15 and when I put them in, my PC won't do anything. The fans turn on, but that's it. There is no bios beep, it's like only the fans are working. The new kit works perfectly when I take the old ones out in any slot configuration. What could I do?
If I were you, I would install the old kit, then adjust the BIOS settings to be manual. This let's you raise the voltage up a little, like from 1.8 to 2.1 (check specs on your RAM). You might want to specify the manual timings for the RAM (5-5-5-15).
Once you've adjusted the voltage and timings to be manual, reboot, see if the old ram by itself boots at this setting. If it does, try adding the new ram.
If it still doesn't work, try adjusting the timings to slightly lower, like 5-5-5-18, 5-5-5-25, or 6-6-6-25.
If you are overclocking, that changes alot, please tell me if you are.
Thanks for your reply. I've raised DRAM voltage from 1,8 to 2,1V , DRAM termination from 0,9 to 1,05V, channel A reference from 0,9 to 1,05V and channel B refference from 0,9 to 1,05V. That didn't help as I was getting the same problem. Then I adjusted the timings to the values you specified in your post but still nothing.