K7N2-L & Corsair XMS2700cas2: no post in dual DDR

Question

Hi,
I have a small problem here, I am assembling a rig for a friend, same hardware (CPU 2400+, ram XMS Corsair, vga ATI 9x00Pro, etc) as mine.
While mine never had any problem, this second rig (512Mb of Corsair XMS PC2700cas2, 2 sticks 256Mb each) is driving me nut because of memory: no way to use both DDR channels.
I tried to use only one stick, runs fine in any slot: DIMM 1, 2 & 3. I tried BOTH sticks in each DIMM, everytime runs OK.
Two sticks run OK only when placed on same channel (DIMM 2 & 3).
NO WAY to have them running in DIMM 1 & 2 or 1 & 3. Swapped sticks between them when making trials, no differences.
I can change bios setting from SPD to Auto or Manual (and different timings too), no difference, still no post with dual channel.
I tried to change memory: I have two sticks of XMS Corsair PC2400cas2, it works fine even in double channel and I can place them in ANY combination I want.
If i try to run the XMS PC2700cas2 sticks on another mobo they work fine..
I have a 256Mb stick of A-Data PC2700 cas2.5 too, and I tried that plus a XMS PC2700cas2 in Dual DDR, they wok fine! Normally they tell you NOT to mix brands to avoid problems, in this case mixing brands worked fine.
What is even more interesting is that I CAN USE THE XMS PC2700cas2 IN DUAL CHANNEL IF I ADD THE THIRD STICK OF A-DATA IN DIMM2 (XMS PC2700 in DIMM 1&3, a combination that NEVER worked, plus A-Data in DIMM 2).
My friend of course refuses to mix ram like that or to run the rig with 768Mb (apart from the fact he doesn't want, we can't, as this PC is a gaming rig he's using Windows 98SE as OS, hence the 512Mb limit...)
Another funny strange symptom: on bios I see the rows only listed as single row, for instance, DIMM 2 that should be listed as populated row 2&3 only shows row 2, ram count shows correct amount though, both in POST and bios page.
Using original bios v.3.2 the original Vdimm is show as 2,6v, if I try to overvolt a little to 2,7v, hoping it can help for two channel configuration it can't save the value, after rebooting is again at 2,6v.
I know this is a known issue of MSI bios, any workaround, apart from flashing one of the even more buggy newer bioses?
thanks
zip

Answer 1

ok first off wut board is this a delta-l or a original k7n2-l board
second wut is the power supply rated at and wut are the numbers off the side i am running the exact same ram and mine are in slots 1 and 3 and work just fine if you can put em in lots 2 and 3 and it boots then it is in dual channel mode as the 1 and 2 are one channel and the 3 slot is the seond channel on the board
it could be a underpower problem as these ram chips due use a lot of voltage
and as far as win98 you can run more then 512 mb in it u just need too make sure u use the 384mb registry tweak so it will use the whole amount of ram
answer these and it may be easier too help ya