Need help finding what's wrong.

[Dabombinable]

I'm having to use my P5Q Turbo for its onboard audio (or more specifically, its front panel audio header, I'll have a sound card for my external speakers), and as a result I need to find out why RAM slots 1&2 aren't working. so far these are the tests that I've done so far:

• Tried it with all RAM slots empty, memory bios error beeps when turned on (
• Tried it with slots 3 and then 4 filled with each of my sticks of DDR2 (800MHz-1066MHz), motherboard posted, Memtest showed no memory errors.
• Tried all sticks in slots 1&2, motherboard won't post and memory error beeps don't occur, so the RAM is recognised as installed
• Tried all sticks of RAM in P5Q Deluxe (dead onboard audio), all work and Memtest shows no errors
• Tried using various CMOS batteries, including those that came with my H87M Pro and Z97 Sabertooth, the problem persisted.
• Tried my GTX 970 G1 instead of my GTX 650ti OC 2GB, problem persisted
• Tried all 5 of my ATX PSU, problem persisted
• Tried all of my LGA775 CPU and my LGa771 Xeon (last ditch effort, memory controller is in the Northbridge), the problem persisted.

Can anyone help me find exactly what has gone wrong? I had updated the bios (well before the issue with the RAM slots occurred) to the latest as I was installing the Xeon, and the motherboard had no issues for a few months..

[DunePilot]

Probably a dead channel, damaged trace, maybe your socket has some bent pins. If 3-4 work though just live with it.... 

[Dabombinable]

12 minutes ago, DunePilot said:

Probably a dead channel, damaged trace, maybe your socket has some bent pins. If 3-4 work though just live with it.... 

Problem is that 8GB DDR2 sticks are expensive AF, and as a result I'm limited to 4GB with it.

[DunePilot]

I wouldn't toss more money at it for sure. You can get by with 4GB but yeah it sucks you have spares laying around you can't use. Sorry bud. Sounds like you did descent troubleshooting but I think you might be out of luck on that one.