A7V133 Memory problem

[Michael Taylor]

I have an Asus A7V133 motherboard on which I'm having problems using 2 x
512Mb PC-133 SD-RAM DIMMS from Crucial.

The PC boots fine, no post errors, the memory test reports 1024Mb RAM, but
when the OS loads (WinXP Pro SP2) it freezes early on (before the Windows
logo appears).
I've run memtest on it which reports no errors.
I can use either of the DIMMS on there own with no problem, and in any of
the 3 DIMM sockets. As soon as I try to use 2 of them in any socket
combination, the OS won't load.

It's CAS2 memory. I've set it to use 'By SPD' in the BIOS, and tried
manually tried as CAS3, but no luck.

The motherboard manual indicates it will accept 3 x 512Mb DIMMS, CAS2
PC-133. I've loaded the 1010 level beta BIOS (to support LBA for large
HDD's - a later upgrade).

I'm rather puzzled, when I've had memory problems on other system, memtest
has always found the problem, or the motherboard issued a post beep of some
sort, but i've never had an OS freeze like this.
I tried loading Windows XP in safe mode, and only about 10 or so device
drivers and/or system DLL's are loaded before it stops responding.

Any ideas why this won't work?
Thanks
Mike

 

[Egil Solberg]

Any ideas why this won't work?

Your troubleshooting seems to be clever enough. I would try to adjust "Dram
read latch delay" in BIOS. Try different settings. When using more DIMMs,
these timings become more important.

 

[Michael Taylor]

Thanks Egil, I will give that a try. I contacted Crucial who suggested I
should downgrade the BIOS to 1003. The earliest I can downgrade to is 1004 -
I can't find 1003 on the Asus support site or their FTP server.
Mike

 

[Wookie]

A bunch of versions here

http://www.amdmb.com/files.php#Asus

 

[Michael Taylor]

Thanks Wookie
Mike

A bunch of versions here

http://www.amdmb.com/files.php#Asus

 

[Michael Taylor]

Egil,
Thanks for your suggestion. I tried various read latch delay timings and the
one that worked for me was 2.69ns.
Your help was very much appreciated.
Regards
Mike