Faulty or Counterfeit Ram?

[blckgrffn]

I have an old, old Compaq N600c that recently came into my possession that I am doing a budget refurb on. New battery $25, G cardbus card $9, Ubuntu 10.04 free, etc.

256 MB ram for ~$22 to go with the existing 256MB stick and now we have a problem.

HP clearly states that it can support up to 512 MB SDR so-dimms (if and when they become available! Such huge amounts of ram!)

When I put in the stick and have the "fast boot" enabled it identifies the 256MB stick as 256MB, then promptly reboots.

If I let it run through the old-school memory check on boot (you remember this!) which takes about 30 seconds, it will get to ~131MB and beep and say there is a memory mismatch, but the PC will then boot and work just fine.

It does this in either slot, with or without the second stick present.

I think this is a 128 MB stick (didn't that show up as ~131MB system memory???) that is intentionally mislabeled/misprogramed to post as a 256MB stick.

Does that actually happen though? I'd like to know before I get after the Amazon seller.

Thanks in advance!

[blckgrffn]

Any help out there?

[Ben90]

Can you see what is printed on the actual memory chips?

[Blain]

Create a bootable Memtest86 .iso CD and run it on each module.
I highly doubt some seller is mislabeling ancient PC-133 to try and snag your cash.

[tcsenter]

Sounds like high density issue.

[Blain]

Originally Posted by tcsenter

Sounds like high density issue.

I thought about that, but the Crucial web site shows the laptop accepts 512MB modules, which from what I remember are high-density.
But without knowing the component specs involved, density may be the issue. It's been a long time since I've dealt with the Intel density factor.

[mikeford]

Maybe the firmware needs to be updated before the higher limit on memory works?

Some of the old systems were real fussy on memory.

Here is the info page at HP, two things caught my eye, there is no memory configuration listed for 2x 256, only 1x 512, and it says only use Compaq memory.
http://h18000.www1.hp.com/products/q...iv.HTML#Memory

[tcsenter]

Originally Posted by Blain

I thought about that, but the Crucial web site shows the laptop accepts 512MB modules, which from what I remember are high-density.

512MB modules can still be built from x4-wide DRAM = not supported until Intel DDR-supporting chipsets (and even then, most OEM BIOS don't support them).

[blckgrffn]

Thanks for the input guys - I'll post whats screened onto the chips later today.

FWIW, even by itself, the stick is recognized as 131 MB and the working stick is 256 MB. So I would expect it to work by itself if 256 MB is the limit.

I did not see an updated firmware listed.

And of course it would say to only use Compaq ram! The seller specifically listed the N600c in their description of the memory...

What am I looking for from memtest in this case? I can run the stick as a 128MB module and it boots, if I try to run it as a 256MB module it posts and then immediately reboots, infinite loop style.

[Blain]

Run the Memtest86 boot .iso and see if errors are generated.

[mikeford]

You have a working 256mb stick, and bought another that doesn't work that the vendor specifically listed as working with the N600C .... Send it back.

[blckgrffn]

48LC16M16A2 - 75

http://www.datasheetarchive.com/48LC...datasheet.html

2M x 4 x 16

https://www.google.com/search?q=2+Mb...hrome&ie=UTF-8

That's 16 MB per chip x 8 chips = 128MB of SDRAM on my "256MB" stick. Awesome.

Unless I am reading that wrong - which is entirely possible.

Memtest is A-OK.

Originally Posted by mikeford

You have a working 256mb stick, and bought another that doesn't work that the vendor specifically listed as working with the N600C .... Send it back.

Working on it now. I don't feel that I should have to pay to ship it back, though.

[tcsenter]

Originally Posted by blckgrffn

48LC16M16A2 - 75

Unless I am reading that wrong - which is entirely possible.

That's a Micron part # that corresponds to 256MBit DRAM (16Mx16).

In order to get 256MB using this, it would need to be double rank. Does it have 8 chips on one side or four chips on each side? Either way, these double-rank x16 modules were hardly supported by Intel (and still aren't). I'm looking for a datasheet on the Intel 830M to be sure, but I can tell you with 95% confidence its not supported either by the chipset or the OEM BIOS.

[blckgrffn]

Originally Posted by tcsenter

That's a Micron part # that corresponds to 256MBit DRAM (16Mx16).

In order to get 256MB using this, it would need to be double rank. Does it have 8 chips on one side or four chips on each side? Either way, these double-rank x16 modules were hardly supported by Intel (and still aren't). I'm looking for a datasheet on the Intel 830M to be sure, but I can tell you with 95% confidence its not supported either by the chipset or the OEM BIOS.

It has four chips on each side. Thanks for the real information I read that value I posted from a pdf from what must have been a different site.

So this might mean that there is really 256MB of ram there but the chipset can only really address half of it?

The current (original via compaq so far as I know) stick is also four chips to a side. This makes it dual rank as well?

EBS26UC6APS-75 which corresponds to 32M x 64bits dual rank if I successfully used Google this time.

[tcsenter]

Originally Posted by blckgrffn

It has four chips on each side.

Yeah I forgot for a minute that we were dealing with SO-DIMMs, which could hardly be built any other way using SDRAM-era devices.

Thanks for the real information I read that value I posted from a pdf from what must have been a different site.

Well it turns-out we were both wrong. This Intel 830 chipset is an odd-ball one in that, according to the technical specs, appears to ONLY support x16 DRAM configurations, not even x8 (which is more standard). I guess more laptop (and embedded) chipsets would support x16 DRAM than desktop since it saves chip count per side, but I wasn't aware of any Intel chipsets that only supported x16. The Compaq Elpida module is x16 as well (double-rank).

Also it seems the chipset only supports PC133 @ 133MHz. No mention in the tech specs or datasheet about supporting 100MHz operation.

Have you checked for a Compaq BIOS update? Only things I can think of are the BIOS isn't handling the module correctly or its defective.

[mikeford]

Originally Posted by blckgrffn

Working on it now. I don't feel that I should have to pay to ship it back, though.

You have a problem that it appears a small amount of money will solve, your call on how much time that money is worth.

This is old hardware, will you be running some linux or W98se?

W98se I recall had a fairly low max memory, is it critical to max it out?

Are you sure this old laptop is actually in good working order? Any battery issues (sometimes old battery types are expensive).

If you are gungho to push ahead, I would find a reliable vendor for replacement ram and buy a stick before sending back the one you suspect has trouble. If the new stick works, you have a stronger argument the first stick was defective. If the new stick also fails maybe its an issue with the laptop and not either vendors fault.

[blckgrffn]

Contacted seller, they sent me a return label and are advancing me another stick of ram. If that still doesn't work, I'll send it all back and figure out what is going to be the path forward. You're free to point out that I should have done this from the get go.

@ Mike : The thing runs Ubuntu 10.04 nicely, but really needs at least another 128MB to help it get over the hump. With 256 and a couple firefox/chromium tabs, it pages out ~80MB. With even the half stick in there, it basically didn't page and performance was actually respectable.

New battery for $25 - and ubuntu reports ~3hours of life expectancy out of it

I figured $60 into a laptop for a cousin of mine who is ~6 yrs old is a reasonable investment. This Evo is a tank that has nice screen, and I don't think the 1.2Ghz P3 is that much slower than an atom.

There is one new minor bios release, but it requires either a floppy (don't have), XP installed (not going through that much pain...), or having the HP network management server setup. Googling left me without a good way to use a floppy .img and a burned disc in conjunction, although I did get the contents extracted.