Can't run dual channel on GA-EP43-UD3L

[DCF1942]

Got a GA-965P-DS3 rev 3.3 a few years ago. The board won't run memory in dual channel. It won't post if I install RAM in slot #3 or #4, but runs fine when #1 or #2 or both are occupied. I have tried varies brands of RAMs, Crucial (it's on the compatibility list), Corsair, OCZ, PNY, Kingston, Super Talent, at different BIOS settings. Didn't want to take my system apart again (had same problem with a refurbished board, but this one was new), so have been running single channel for a few years.

Now I'm thinking to use all 4 slots to run 8GB or more for Win7, so I finally RMAed it and put in a GA-EP43-UD3L. To my surprise, I still can't run dual channel. Anything in #3 or #4 result in the dreaded reboot loop, but no problem when using #1 or #2 or both. I've tried the optimized BIOS and varies settings. The RAMs (Crucial, Corsair, OCZ, all 2x1gb kits) showed no errors after 2-3 hours MemTest86+. This has happened on 2 GA-EP43-UD3L boards I've tried, both brand new. I have updated to the newest F6 BIOS as well.

Since the memories are OK, it appears to me the boards are bad, but all 3 brand new ones? Are these Gigabytes boards so picky on memories? If the memory kit is not a perfect pair, I should be able to run a single chip in any slot right? Anyone know what's going on? Thanks.

My settings:

Intel E7500 (had E4300 before)
GA-EP43-UD3L, F4 or F6 BIOS
2x1GB DDR2-800, Crucial or OCZ
XFX 8800GT
Antec NeoHE 430W

[wazza300]

are you installing it in the correct colour coded slots?? i dont know your board so maybe someone will advise you better.can you run dual channel with both sticks in slots #1and#2? you may need a full 8gb installed to enable slots #3 and #4 i cant say tho for sure

[Chike]

I do hear something about bad luck strike in 3s.

Have you tested ports 3 and 4 alone with single stick of ram?
Have you tried to clear CMOS(2nd part of the post) and load optimized defaults?
Can you post links to your memory kit specs?

[Johnysmoke]

I'm not certain but it seems like it has to be the ram. Do you have the ram set to 1.8volt? There must be something going wrong some where because i am using that same board now, GA-EP43-UD3L without any problems what so ever.
Check my specs below in sig.

I having been using 2 kits of Kingston 4096MB PC6400 DDR2 800MHz KVR800D2K2/4GR , 8Gb total and running dual channel since April and everything has been working very well. I loaned my pops a 2gb stick and ran 6gb on this board for a little while and it worked fine then as well.

Check your voltages, Try 1.8v , I do know this board is picky about about the ram voltages. That is all i can think of at the moment. If that doesn't fix it try some Kingston ram if you can get your hands on some.

[DCF1942]

Turns out the mobo is bad. Went back to my local Fry's exchanged a new one (they only had a few returns couple of days ago), now everything is back in order. Guess Chike heard it right, bad luck does strike 3 times :).

Thanks for the help everyone.