ASUS M5A78L-M/USB3 - memory issue

[Xenopus]

I recently had my PC open to install a new firewire card, and thought I'd try putting in some extra RAM I had lying around. I inserted it into a spare slot, and it clicked in, but didn't feel quite right. I removed it and realised it was DDR2 RAM (not quite sure how it managed to click into the DDR3 slot). This was done whilst the PC was powered off and unplugged - I did not power up the PC with the DDR2 RAM in.

When I did power up the PC it wouldn't boot and I'm getting an alarm from the motherboard - 1 long and 2 short beeps, which according to ASUS' website is a memory issue beep code.

This is what I've tried so far:
-Shuffling around the existing RAM (2 sticks) in different slots
-Using 1 stick of RAM only, tried each of the four slots (and with each stick of RAM)
-Clearing CMOS
-Checking for obvious debris/pin damage in the RAM slots
but I'm still getting the same beep code

So, have I:
a) Fried my original DDR3 RAM
b) Destroyed my motherboard, or
c) Something else stupid

If I could be sure the problem was a) or b) then I'll just buy new RAM or a new motherboard. Any advice on likely cause and how to solve it would be greatly appreciated!

 

[raja@asus]

Could be a combination of what you suppose above about frying your DRAM or worse, the DRAM, voltage regulation circuitry and the memory controller on the CPU. The pin out for DDR2 is totally differnt to DDR3 - you could have had current going into all sorts of places it should not be.

 

[Xenopus]

Even though I didn't power the system on? Is it worth trying new RAM as a first step?

 

[raja@asus]

If you did that with the board powered off - it should have no impact at all on the board working with the original configuration. I am left a little confused as to why the board will not now POST in the original config if it was not powered on - unless there is some form of physical damage.

You can try removing the CMOS battery for a while and see if that helps bring things back to POSTing again.

 

[manofice]

If you did that with the board powered off - it should have no impact at all on the board working with the original configuration. I am left a little confused as to why the board will not know POST in the original config if it was not powered on - unless there is some form of physical damage.

You can try removing the CMOS battery for a while and see if that helps bring things back to POSTing again.

yeah only thing that makes sense if you damaged the ram slots or something

 

[Xenopus]

Thanks guys.

I've already tried removing the CMOS battery, and that didn't work (although I only removed it for a minute or two). If I have damaged a RAM slot, is there any way to fix it (or switch off that slot), or would I need a new motherboard?

 

[raja@asus]

No way to switch off a slot. If it is physical damage to a slot you should be able to see it - for physical damage to prevent a board from posting, one would expect to see bent socket pins that are shorting into each other. To be honest though, that's something hard to imagine even if the wrong type of module was forced into the slot...

Anyway, if there is such a problem, yes you would need a new board.