Half my memory disappeared

[foggythecat]

A friends computer is 3 years old running an Athelon S939 at 1.8GHz. Motherboard is an MSI K8T Neo2 MS6702E. Memory is Crucial 3200 512Mb dual sided running at stock 200MHz

I noticed Windows XP SP2 with current patches was reporting 256 MB. Ran Memtest 86+ 1.70 which also reported 256 Mb

I changed memory to a new Corsair VS V85512MB00 512Mb dual sided and verified it was in the correct DIMM #1 slot. No change – also 256Mb reported

I moved memory to Dimm2 – no boot (as expected)

I returned it to DImm1 and added 512Mb to Dimm3 to bring installed memory to 1028 – no boot (not expected)

I returned it to the original Crucial 512Mb and reseated the CPU chip. Memtest and XP still report 256Mb

I also noted the Memtest reports memory as 256M but Testing: 116K – 256M 511M Is it indicating there is 512M equipped???

I am not aware of any BIOS settings that would limit memory. The motherboard is fairly modern and supports DS DIMMS to 1Gb. I am suspecting a processor or MB failure. Computer is happily running but only using 1/2 of the memory. Any ideas?

 

[chookman]

You dont have some type of onboard video or a turbo cache video card do you?

 

[darkguset]

Did you go through your manual?
Some old motherboards are not compatible with double sided memory, or they require strange configurations in order for them to work properly.
Or it could simply be a RAM module incompatibility.
Check with your manual or motherboard maker website first.

 

[Mondoman]

You may want to try a different brand of memory. Corsair's Value Select line is just contracted out to the cheapest bidder and so has a relatively high rate of incompatibility/defects, unlike Corsair's premium lines (XMS and so forth).
Kingston tends to have good quality even in its "value" line.

Edit: My bad (thanks badge!) - I spaced and wrote Crucial instead of Corsair. Fixed now. OP is probably right about MB or CPU problem. I'd check the MB for bad capacitors: bulging or leaking "aluminum can" components.

 

[badge]

Hopefully a 512 Kingston Value unit will show up in my rig as 1GB. Mondo...do you mean Crucial is selling low quality dimms with their value line? What about Corsair value select?

OP: Try the DIMM in another system and confirm you have a 512 and not a 256 dimm. Also, try downloading CPUZ and check the RAM status their.

 

[royalcrown]

Corsair does everything in house, their value ram is fine...

 

[Mondoman]

RC - check out their website; they try to give you the impression they don't, but if you read the words carefully, you'll see that they do contract out the ValueSelects.

 

[foggythecat]

Thanks for the suggestions.

Both the Crucial and Corsair memory behave the same strange way, so I beleive it is either the processor's memory controller or motherboard that is allowing only one bank of the dual sided DIMM to be read. Yes the board does support dual sided and it used to work OK. I will try CPUZ - I didn't think to run it.

I think the quickest cure is to upgrade to a new processor, motherboard and DDR2 memory. The rest of the computer (case, Power supply, Serial hard drive, DVD, display, keyboard) can be salvaged and will be just fine.

 

[foggythecat]

Further to the abouve, I did run CPUZ and it showed all 512 MB. Too bad XP and Memtest can't find it! Here is the CPUZ report on the memory



Memory
DRAM Type DDR-SDRAM
DRAM Size 512 MBytes
DRAM Frequency 200.0 MHz
FSB😀RAM CPU/9.0
CAS# Latency 3.0 clocks
RAS# to CAS# 3 clocks
RAS# Precharge 3 clocks
Cycle Time (TRAS) 8 clocks
Bank Cycle Time (TRC) 12 clocks
DRAM Idle Timer 16 clocks
# of memory modules 1
Module 0 MOSEL DDR-SDRAM PC3200 - 512 MBytes

 

[Mondoman]

If you haven't yet, you should use an air duster on all 3 DIMM slots to make sure there isn't any slightly conductive dust bridging some connections or otherwise messing up the memory bus.

 

[foggythecat]

Thanks. I will try that. The inside was quite clean and I have removed and inserted DIMMs in slots 1,2,3. I did not use slot 4 or blow them out.

 

[djcoolmasterx]

What graphics card does it have?

 

[foggythecat]

It would be an entry level ATI AGP with a DVI interface. Sorry, I don't have the model number here