Could PSU be limiting my max memory

[klandingham]

Hello,

I've inherited an old HP Pavilion 7955 that I'd like to use as an extra machine. It originally came with a 1.5 GHz Pentium 4 and a single 256 MB DIMM memory module (MB has 3 DIMM slots.) When I received it, all three memory slots had 256 MB sticks, so it was running with 768 MB.

From what I've gathered, the motherboard in this machine is an ASUS P4B-LA (Amazon) and specs at HP state that its max memory is 1.5 GB (which I assume means 3x512 MB)

I'm planning on putting a 2.4 GHz P4 in it, but my first step is to max the memory.

So, I bought 3 512 MB DIMM modules (PC133, unbuffered).

I removed the existing 256 MB modules and installed the 512's. The machine seems to pass POST (takes a noticeably longer time) then begins to boot the OS (Windows XP) but within a few seconds of boot loading it does a hard reboot.

If I remove any one of the 512 DIMMs (putting it at 1 GB) then it seems to boot and run normally, and Windows seems to see 1 GB properly.

I explored the BIOS settings but as this is a pretty old box, the BIOS doesn't have any settings at all for memory (that I could find.)

It seems that, according to the specs, 1.5 GB should work. Could my problem be inadequate power supply?

Thanks!

 

[gbeirn]

I doubt the power supply would cause that. Either one of the sticks is bad or the memory controller can't handle those specific RAM chip (the board many only support 2 high density chips). I would start running Memtest+ with one chip at a time.

 

[klandingham]

Any two sticks will work...I don't see how one could be bad. But I'll give MemTest a try anyway, nothing to lose. Thanks for your reply.

 

[RebateMonger]

2004 post showing same problem as you.

"Hi Dave
I also have a 7955 and I'm not sure about high density compatibility,but I do know that a 512mb I tried in mine caused a no boot.Even though HP says this model can use 512mb sticks I had no luck and settled on 3 256mb sticks.Which is very adequate for all I run,including some very demanding programs at times."

=====================================

Crucial's site, when queried for the Pavilion 7955 says:

Maximum Memory: 1024MB
Slots: 3 (3 banks of 1)
Standard Memory: 256MB removable
USB Support: 1.x Compliant
Although it is physically possible to install more memory, the system will only recognize the maximum listed. Installing more memory may cause major problems. Consult the system's manufacturer for more information.

I'd say you are stuck at 1 GB of memory.

 

[klandingham]

Looks like I'm lucky to be getting 1GB!

Thanks very much for taking the time to post this info. Cheers.