Not dead - but not looking that well... :)

This is a strange problem.

PC won't POST after being properly shutdown and turned off for about 6 hours.

BUT will Restart fine everytime,
and will start fine even after being turned Off for about 1 hour
(haven't tried times between 1-6 hours).

Main change was the installation/addition of 1Gb memory module to existing 512Mb RAM (total RAM = 1.5Gb).

The 1Gb module added in fine, and the machine started fine after the addition.

Ran MemTest 3.7 for several hours to over 600% and found No errors -
I also did several restarts and ran the PC all day with No problems -
so I thought everything was fine -
until I shut down the PC and turned off at the mains overnight -
next morning the PC would not start/POST.

Tried to turn the PC on several times - eventually the PC started, but showed CMOS checksum error.

Ah, CMOS battery - changed it out for a new one, and reset CMOS -
checked the BIOS settings - and PC started OK, set the date/time.

PC worked fine all day including some restarts and MemTest 3.7 for over 100% - No errors

Shutdown the PC at the end of day and turned off at the mains -
next morning same thing - PC would not start/POST.

Removed 1Gb RAM - PC started with CMOS checksum error - but clock was right.

Turned Off PC - reinstalled 1Gb RAM (total 1.5Gb) - PC started fine and Passed all tests (MemTest to over 300%) - ran fine all day.

I've also exchanged the RAM modules on the 2 slots - same problem.

I've tried the PC with just the 1Gb RAM (removed original 512Mb) and PC still will not start/POST after being turned Off overnight.

So it seems if I want to use the 1Gb RAM - I canNOT turn the PC off overnight (which is my preference) -

It is strange that the PC will do restarts fine everytime.
Also even when shutdown and turned Off at the mains for about 1 hour - the PC will start fine.
I have also ran MemTest 3.7 several times and found No errors.

So what can be the problem?
It seems pretty obvious that the new 1Gb RAM is the culprit -
but WHY?

I did several months of research before doing this upgrade and inquired at eMachines and several RAM manufacturers about compatibility and adding the 1Gb to the existing 512Mb to get 1.5Gb -
even asked about chip density since the original memory is double banked -
(because of these posts I found -
Memory problems - Computing.Net
Ram question - Computing.Net)
but all said no problems as long as it was PC3200/DDR400 184-pin.

I bought a Crucial 1Gb PC3200/DDR400 184-pin module Model CT12864Z40B - OEM -
I even double-checked before purchase at to make sure the specific model was compatible with my PC and Motherboard.

PC details -
eMachines W3107
Motherboard: First International Computer, Inc.
K8MC51G (ver. PCB 1.x )
Manufacturer : Phoenix Technologies, LTD
Version : 6.00 PG
Date : 11/25/2005 (mm/dd/yyyy)
OEM Signature : Version NAA21EM

Operation system:
Windows XP Home Edition
5.01.2600 Service Pack 2
(regularly kept up to date - not upgrading to SP3 yet)

Original existing memory:
A0 (RAS 0, RAS 1) : 512 (Double Bank)
Information SPD EEPROM (A0) :
Manufacturer : Nanya Technology
Part Number : NT512D64S8HC0G-5T
Type : DDR-SDRAM PC-3200 (200 MHz) - [DDR-400]
Size : 512 MB (2 rows, 4 banks)

Newly added memory: (bought as Crucial Model CT12864Z40B - OEM)
A1 (RAS 2, RAS 3) : 1024 (Double Bank)
Information SPD EEPROM (A1) :
Manufacturer : Samsung
Part Number : M3 68L2923DUN-CCC
Type : DDR-SDRAM PC-3200 (200 MHz) - [DDR-400]
Size : 1024 MB (2 rows, 4 banks)

Any suggestions, please?

I do want to have at least 1Gb of RAM in my PC - but don't want to return this 1Gb and buy some other RAM and find it's just going to give me similar problems........

Many Thanks,

Recommended Answers

All 5 Replies

In my experience Ram is the most troublesome piece of hardware in a computer. Ram problems can be so random and confusing. I would say return the 1GB stick as dead on arrival. have them send you a new one and try that. if it still does it make sure you system will support that much ram, some older machines will only support a gig

I would say return the 1GB stick as dead on arrival. have them send you a new one and try that. if it still does it make sure you system will support that much ram, some older machines will only support a gig

Thanks for the quick reply.

I did a live chat at describing the problem -
they said it was a bad module and asked me to return it for exchange.

In the meantime to make sure it wasn't some other problem - I removed the new 1Gb RAM earlier today and had the PC powered Off for about 4.5 hours - the PC started fine -
I'll see if the original configuration will still start/boot after a power off overnight.

Yes, my PC can support 2Gb max in 2 slots, at 1Gb max for each slot.


It sounds like you did your research before adding RAM. you wouldn't believe how many people just add as much ram as they can then they can't figure out why it isn't working.

But it sounds like the problem is solved. Keep us posted as to how the new ram works out. In the mean time you can mark post as solved and if you are feeling extra generous feel free to add to my reputation.

Glad i could help
Thank you

But it sounds like the problem is solved. Keep us posted as to how the new ram works out.

Many thanks.

My PC booted/POSTed fine this morning after a full power off overnight with the original 512Mb (and new 1Gb removed) -
so it would seem that the new 1Gb RAM was the culprit.
(with just the 1Gb RAM installed (original 512Mb removed) PC would not boot/POST after ~6 hour power off).

Of course it's merely academic now - but I can't figure out why with the 1Gb installed why my PC would restart, and even boot/POST fine after ~1 hour power Off - but fail to boot after ~6hour power-Off -
other than to just say "it doesn't work" :-O

However there is just this very slight doubt about the RAM being double banked - as in these threads -
Memory problems - Computing.Net
Ram question - Computing.Net
They were saying the PC/MoBo only supports 2 Banks of 1 - and the original 512Mb RAM is already Double Bank=2 Banks? - so it has already taken up the maximum number of banks -
BUT before purchase I asked several times both at eMachines and a number of RAM manufacturers if this mattered and they all said NO.
Also if this was right about the banking the 1Gb RAM shouldn't have worked at all with the original 512Mb RAM -
and should have worked fine on its own which it didn't (at least PC would not boot/POST from ~6 hour power-Off)


the number of banks shouldn't matter. but as far as why it doesn't work, like i said earlier, ram can cause some of the most confusing problems, things that you would never even think ram was associated with. it's just that everything runs through the ram and if one thing goes wrong with the ram then the whole machine can fail.

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