Help! Won't do dual channel!

[Crashman]

I was messing around with the IDE cables on this Soyo P4I875P Version 1.0, and when I went to restart I got the "no RAM" beep. Various diagnostics show it can use all 4 slots, but not in dual channel mode. Any attempt to put matched modules in 1 and 3 or 2 and 4 result in the error, but mixing modules to force single channel mode works fine.

The system has been in use for several months, any ideas what might be causing these problems? Tested with several types of RAM, even underclocked/overvolted/raised latency.

<font color=blue>Only a place as big as the internet could be home to a hero as big as Crashman!</font color=blue>
<font color=red>Only a place as big as the internet could be home to an ego as large as Crashman's!</font color=red>

 

[Ned_Flanders]

you've had dual channel on the board before you changed the IDE cables?

<font color=blue><font color=red>Blow</font color=red> Dry <font color=red>my ass</font color=red> and call me <font color=red>Eden</font color=red>!</font color=blue>

 

[Crashman]

Yes! I don't know what I could have "bumped" in the process, but now it won't work with EITHER pair of previously working modules. Both pair are PC4000 and won't even work in dual channel now at PC3200 speed, even though they both worked before in dual channel at all speeds up to DDR500.

<font color=blue>Only a place as big as the internet could be home to a hero as big as Crashman!</font color=blue>
<font color=red>Only a place as big as the internet could be home to an ego as large as Crashman's!</font color=red>

 

[Ned_Flanders]

Try returning to the original cable setup...see if it works then?

Sounds very odd. I've never heard of a jumper that controlls dual channel, so you knocking a jumper off the board is out of the question!

<font color=blue><font color=red>Blow</font color=red> Dry <font color=red>my ass</font color=red> and call me <font color=red>Eden</font color=red>!</font color=blue>

 

[Cybercraig]

Welcome to the wonderful world of "875" boards! Flash BIOS and try again.

Abit IS7 - 2.8C @ 3.4 - Mushkin PC4000 (2 X 512) - Sapphire 9800Pro - TT 420 watt Pure Power
Samsung 120gb ATA-100 - Maxtor 40gb ATA - 100
Sony DRU-510A - THAT'S MORE LIKE IT!

 

[Cybercraig]

Let me guess, they will work in dual-channel at PC2700 speeds? They come up at 333mhz in BIOS?

Abit IS7 - 2.8C @ 3.4 - Mushkin PC4000 (2 X 512) - Sapphire 9800Pro - TT 420 watt Pure Power
Samsung 120gb ATA-100 - Maxtor 40gb ATA - 100
Sony DRU-510A - THAT'S MORE LIKE IT!

 

[Crashman]

Hehe, of course I tried that. I have no idea what happened, unless something happened at the time I shut down. I answer the easy question, so you know whatever I asked was going to be tough!

<font color=blue>Only a place as big as the internet could be home to a hero as big as Crashman!</font color=blue>
<font color=red>Only a place as big as the internet could be home to an ego as large as Crashman's!</font color=red>

 

[Crashman]

Haven't tried underclocking them below PC3200 speed. I'll tell you what, I'll TRY reflashing the BIOS, and if that doesn't work, I'll TRY running it at DDR333. But remember, this board was previously functioning with BOTH pairs at DDR500, and now it won't even do DDR400 with either pair.

<font color=blue>Only a place as big as the internet could be home to a hero as big as Crashman!</font color=blue>
<font color=red>Only a place as big as the internet could be home to an ego as large as Crashman's!</font color=red>

 

[Cybercraig]

That's pretty close to what happened with my MSI board when I switched to Mushkin PC4000. They would show up as 333mhz, or a single stick would run fine at 400+. I changed the power supply because my 3.3v rail was down to 3.18v. No dice! I tried everything until MSI sent me a beta BIOS that turned the 875 into an 865. At that point, I punted! I figured the 875 chipset hated Mushkin!

Abit IS7 - 2.8C @ 3.4 - Mushkin PC4000 (2 X 512) - Sapphire 9800Pro - TT 420 watt Pure Power
Samsung 120gb ATA-100 - Maxtor 40gb ATA - 100
Sony DRU-510A - THAT'S MORE LIKE IT!

 

[Crashman]

Nope, it can't be an issue with the modules, because the system was up for months with one set of modules, and up for days with the other, in dual channel mode. And I did try a BIOS update just to make sure the BIOS hadn't been corrupted. The only thing that leaves is a hardware issue with the board itself, I think I'm going to have to pull it in order to make sure there's nothing affecting it (such as a metal shaving).

One more note: One set of modules is XMS Pro, and the activity lights show normal RAM behavior when the system refuses to boot, it's like it's misdetecting a non-existant hardware problem.

<font color=blue>Only a place as big as the internet could be home to a hero as big as Crashman!</font color=blue>
<font color=red>Only a place as big as the internet could be home to an ego as large as Crashman's!</font color=red>

 

[Cybercraig]

Beats me. Make sure you post how you fix it.

Abit IS7 - 2.8C @ 3.4 - Mushkin PC4000 (2 X 512) - Sapphire 9800Pro - TT 420 watt Pure Power
Samsung 120gb ATA-100 - Maxtor 40gb ATA - 100
Sony DRU-510A - THAT'S MORE LIKE IT!

 

[Crashman]

Hehe, this is a real riot: Soyo put the memory traces right up against the mounting holes for the backing plate (only on the back side of the board), and all the messing around I'd previously done had rubbed through the protective paint. I put some plastic tape in between: Problem solved.

I must have bumped something hard enough to make it get a connection to a memory trace.

<font color=blue>Only a place as big as the internet could be home to a hero as big as Crashman!</font color=blue>
<font color=red>Only a place as big as the internet could be home to an ego as large as Crashman's!</font color=red>