Thinkpad 240 low-density 256MB question

[thinking240]

Hi folks,

I recently bought a low-density 256MB module to upgrade my tp240 to 320MB (currently have 192MB). However, when I plugged the module in, my tp240 did not recognize it and ended up booting off with only the onboard 64MB. When I check the module using a system info program, the SPD from the module reported that it exists and it is a 256mb module. I got the module 2nd hand off ebay and it was taken out from an existing machine. Here is the info:

Part No: 33L3070
Brand: IBM (Mitsubishi chips)

I've read that both 33L3069 and 33L3070 will work on a tp240. Can any one help to shed some light on why it's not being recognized?

Thanks!

[virge]

If your 240 machine already has 64mb onboard, then it may be limited to 192mb total. This is one reason I didn't keep my 240X very long. I used to think it was a definite limitation, but there's a recent development which you can look into to give you 256mb. See this thread:

http://forum.thinkpads.com/viewtopic.php?f=6&t=74473

edit: I didn't read carefully enough!

[thinking240]

Thanks virge for your reply.

No. I don't have a 240X. I have the original 240 (C-300mhz). From what I have read, I can get 320MB via 64mb onboard + 256mb low-density ram. Just very puzzling that it's not working when others have said it worked on their 240.

Any other help would be gradly appreciated.

[rkawakami]

It might be due to the BIOS revision of your system. The original version (1.00 - IRET14WW) appears to have had an error in reporting on the installed memory:

http://download.lenovo.com/ibmdl/pub/pc ... sdir77.txt (Install notes for 240 BIOS)
http://www-307.ibm.com/pc/support/site. ... IGR-496LGR (BIOS download page)

Follow-up revisions made have allowed for additional memory to be utilized. However, before you attempt to upgrade the BIOS, I'd verify that the module is being recognized by the system and has no errors. Download a copy of memtest86+ from here:

http://www.memtest.org/#downiso

and boot the system with that program. There will be a display of the total memory that's detected near the upper left corner as seen in this photo:

http://www.rkawakami.net/280117017149/

If the proper amount of memory is displayed (320MB), then let the system run the diagnostics for at least three complete passes. Any errors that are detected will be displayed in red in the bottom half of the screen. If memtest86+ still reports only 64MB, then I'd check that module in another system, if possible, before considering a BIOS upgrade.

[thinking240]

Hi Raymond,

Thanks for your assistance. Unfortunately, when I test the ram with memtest86+, it could not find the 256mb module (only onboard 64mb was showing up). My thinkpad 240 is alreayd on the 77 bios. Can you think of any reason why the ram won't work other than the module is defective? i have no other laptop to test the module with, but i did get the module to show up in CPU-Z in windows -- not sure how accurate that is, but it was able to read the SPD).

Thanks!

[rkawakami]

Other than a possible problem with the 256MB memory module or your system itself, I can't think of anything else. The 33L3069/33L3070 module is the factory recommended low density module for use with older PC100 systems but they should also work inside a PC66 (like the 240). Searching the archives here says that others have had success in using a 256MB module so I'm confused like you.

It's possible that the module can be reporting the SPD information, even though the memory itself is bad, since that data is transmitted over a different signal interface than the memory. That still brings me back to my original suggestion to try out the module in another PC66 or PC100 system. Maybe check around with some of your friends to see if they have such a laptop. If so, and if they have a 256MB module in their system, try it in yours.

[oski]

Hi,

I have a 256MB low density module working in my 240, and shows 320MB in Bios and in memtest.

You probably have worked out alrerady the reasons for your module not working, but IMHO, the causes could be:
- Defective module, pretty obvious.
- Problems with your motherboard: have you tried any other low density module, say 64 or 128MB? Do they work?
- Is your low density module really low density? Usually they have 16 chips ( 8 in each side ).

Cheers!!!

[thinking240]

Hi Raymond and Oski,

Thanks for your replies.

The CPU-Z is reporting that the chip is MH32S64APFB-7L (looks like 32x64 from the part number, though I can't be sure). The module itself is 16 chips (so it's unlikely to be high-density). I also have a 128MB module previously that was 8 chips and it worked (so it's not the slot or density issue).

I bought this almost 6 months back but never had the time to test this out (and more like forgotten about it until a few days ago). Like you said, the module itself is probably defective. It's unlikely that I can send this back to the seller, so I will probably buy another one.

So the best software for testing RAM is memtest86+? I'll use that on the next module I buy.

Oski, is 320MB significantly faster than 192MB when you run XP? I currently have 192MB, so just want to see if it's worth getting that extra 128MB. I already optimized my XP setup quite a bit, leaving ~90MB RAM free to use for apps (MSN + 2 IE tabs will usually use all of that up).

Thanks again!

[rkawakami]

Searching on that part number (MH32S64APFB-7L) appears to say that it is a low-density (i.e., 16 chip) PC100 256MB module:

http://digchip.com/datasheets/parts/dat ... PFB-7L.php

It's possible that the module does not have the proper SPD information (specifcally, CAS Latency setting) which the system is looking for (I'm assuming that the 240 checks for CL3 support from the module). CPU-Z should be able to tell you the system's CL requirement.

Yes, I would highly recommend that any "new" memory module be tested with something like memtest86+ prior to being put into service. Let it run for at least three complete passes. That gives it enough time to warm up so that any thermal sensitivity would be noticed.

[thinking240]

Thanks Ray.

CPU-Z is reporting CAS#3 for the module. The module also supports CAS#2 as well from the CPU-Z printout.

Based on your experience, how likely is a module to have good SPD information but defective memory chips?

Thanks a bunch!

[rkawakami]

Well, I've seen both cases: good memory and bad SPD info and bad memory with good SPD . The second case is much more common but not as far as having the entire memory capacity of the module disappearing from the system. Usually you see the proper amount of installed memory being reported both by the BIOS and whatever DOS or Windows program you use. Only when you run a thorough memory diagnostic does it reveal some bit failures or dead output pin(s).

I don't know enough about how the BIOS determines how much memory is actually available; whether it simply uses what the SPD says it should be or if the BIOS does a fair amount of testing during the POST period. I would hope that it's a combination of the two. Neither do I have a 240 system to test out some of my modules on so I could definitely say which ones will work or don't. The closest system that I have would be the 600 or 600E but they use a slightly different chipset (440BX vs the 240's 440DX).

[thinking240]

Thanks Ray.

The 240 I have uses the 440BX, so in that case, it is the same as your 600 oe 600E system?

Would be great to know if 33L3069 or 33L3070 actually does work or not in the 240 (or on 440BX chipsets).

Thanks again.

[rkawakami]

My understanding is that the 240 system has the 440DX chipset, as evidenced by the information in the "twbook":

http://www.lenovo.com/psref/pdf/twbook.pdf

Of course, there could be an error in this document but I'm not aware of one. The 33L3069/70 modules do work in a 600E. I just installed a Micron PC133 256MB module (MT16LSDF3264HG-133) in a 600E and it booted with 288MB and memtest86+ is passing. This particular Micron module is one which can carry an IBM FRU. The one I'm currently using has an HP sticker on it. So yes, these modules can work with the 440BX chipset (at least that's what memtest86+ v1.65 says is in my 600E).

[thinking240]

From CPU-Z, it's reporting that I have a i440BX/ZX chipset REV. C1. I have also read elsewhere that the original 240 is a 440BX.

Could it be that my 33L3070 is a PC100 and it does not work "well" with my 66Mhz bus speed? I have a 128MB module PC133 (Hyundai) that works in my 240. Could it be that a 1:2 FSB:DRAM ratio will be more appropriate?

[rkawakami]

The only problem that can occur with a "faster" module not working in a "slower" system would be if the system requires CL2 and the module says it can't support that. Most older PC133 modules couldn't be run at 133Mhz AND CL2. However, they might have been able to deliver 100Mhz at CL2, and by extrapolation, 66Mhz at CL2. If your 240 system requires CL2 (check CPU-Z's memory tab) and your 256MB module only has CL3 enabled, then that might explain things.

I just remembered something along these lines and had to search for it in the archives:

http://forum.thinkpads.com/viewtopic.ph ... 51#p232151

Basically, it was the same problem of installing a module and not having it seen by the system (or generating any error beeps). The modules in that case were supposed to be CL2 rated but the SPD did not reflect that. I used a bench-top memory module tester to fix it. Unfortunately, I do not have access to that system any more.

If you are going to try another 256MB module, I'd look for one which has CL2 on the label.

[thinking240]

Hi Ray,

Thanks for pointing me in a new direction. I used a software called SPDTool to view and modify the SPD on the module. The SPD settings seems alright as compared to the datasheet. When I tried to force the module to support CAS2 only by changing the CAS Latency to 2 only (previously was undefined [06 in SPD Hex), I ended up with a module that reported supporting CAS3 only (which is not what we want). A bit stuck at this point. Any advice?

Thanks.

[rkawakami]

Ummm... "don't use SPDTool anymore?" . I've tried that program before on my T23 and it never seemed to work. Didn't have the urge to use another system though...

The 06h should be the code for enabling both CL2 and CL3. I don't have a JEDEC specification sheet for SPD formats on hand at the moment but I believe that an 04h would be CL3 only and an 02h would be CL2 only.

[thinking240]

Hey Ray,

You are right - 02 did the trick, but my 240 still doesn't recognize the module. I guess that means it really is over (i.e. module is bad), eh?

[rkawakami]

That would be my conclusion, but before spending any more money, I'd try to check the module in another system just to make sure. If there's a problem with your 240, buying another module won't help.

[virge]

That would be my conclusion, but before spending any more money, I'd try to check the module in another system just to make sure. If there's a problem with your 240, buying another module won't help.

Ray, do you know whether memory modules can be picky? I have a low-density 256MB module that I bought for a 600X. Didn't work in the 600X... didn't work in a 600E... didn't work in a 770X, BUT it did work in an A22P.

[rkawakami]

There's certainly been cases where one module refuses to work in one system but performs fine in another. There's a whole bunch of variables that can result in this: BIOS versions, differences in power supply levels, dirty contacts in the memory slot or on the module, marginal parts being used on the module, the module design or layout, bad SPD information programmed into the module, etc. I'm of the philosophy that if the memory doesn't work in two systems in which it should, then there's something wrong with it and it probably shouldn't be used at all (if system stability is important).

Over the past few years I've found a couple of modules which only fail when cold or hot; by "cold", I mean room temperature. A cold boot with memtest86+ and the module would fail. Let it run for several minutes and the errors go away. Same is said for a module which when exercised for several minutes suddenly starts to fail. Temperature is only one external condition which can drastically affect memory operation.

By your saying, "didn't work", what was the reason why the module "failed"? Was it not recognized by the BIOS or caused a boot error? Or did you run a memory diagnostic?

[virge]

I guess I should have been a little clearer. By "didn't work" I mean that the machines would power on, the LCD would light, but they wouldn't post and there were no beeps. I haven't tested whether cold/warm makes a difference, but so far my A22p hasn't had any problems booting. Haven't used it extensively, so we'll see about system stability. I'll run memtest and see if it finds any errors.

[rkawakami]

I'd suspect in that case, there's something in the module's SPD that's preventing it from working in those systems. Why it works inside the A22p, I can't say for sure.

[sjthinkpader]

Looking at the SPD listing in the datasheet for this module, it is made to work in intel systems (byte 127). So likely the module is bad.

[Allstar]

Hi,

This topic seems to be quite related whit the problem i have. But the main difference is that i have X21. So hope you don't mind if i continue here. The problem is that I'm trying to install additional non-low density 256MB SDR SDRAM PC133 to my X21 (2662) system. I have on board 128 SDRAM PC100 and the machine admits the new module. But the on board 128MB doesn't show up anymore. It shows just 256MB in BIOS and system properties. Although the maximum allowed memory is 384. Any ideas?

(Running XP PRO SP2)

[rkawakami]

Welcome to thinkpads.com!

Installing a high density (i.e., non-low density ) module in a system can sometimes result in only 1/2 of the memory being recognized. So I'd assume that the on-board 128MB is being seen/used and only 128MB of the PC133 256MB module. Don't know if there's any "danger" in running your system this way. By danger, I mean any possibility that the system will receive a memory error. I'd highly recommend that you only use the proper low density 256MB module.

[Allstar]

Ok, thanks. Does this memory have a low-density capacity?

[rkawakami]

That Micron module is low density, but it's also only 128MB. A quick way to determine "densityness" (??) for Micron PC100/PC133 SODIMMs is by looking at the part number. In this case:

MT8LSDT1664HG-133B3

"MT" means it's made by Micron; "8" refers to the number of memory devices on the board; "L" means 3.3v parts; "SDT" is the packaging technology used by the memories; "1664" is the size of the module (in this case 16M x 64 bits or a total of 128MB); "H" is 144 pin SODIMM; "G" is commercial temperature grade; "133" is the speed (i.e. 133Mhz, aka PC133); and the "B3" is a revision code for the module design..

The two important fields to look at when concerned about the module's density are the "8" and the "1664" (i.e. 128MB). "Low density" modules are made with 16MB memory devices. "High density" modules are made with 32MB parts. Take the size of this module (128MB) and divide it by the number of parts on board (8) and you get 16MB - low density. So for Micron modules, the following rules apply:

128MB and "MT8" = low density
128MB and "MT4" = high density
256MB and "MT16" = low density
256MB and "MT8" = high density

What you would be looking for in a low density 256MB Micron module would be an MT16LSDF3264. If it's labeled MT8LSDF3264 or MT8LSDT3264, then those are high density.

ref: http://download.micron.com/pdf/numberin ... rammod.pdf

[Allstar]

rkawakami, a simple yes-no answer would have done it . Never expected so thorough reply, but i appreciate it. Yes its 128MB. Of course i prefer more 256MB module, but this model is at the moment the only low-density SDRAM device that i can buy from hand to hand. I got it from a add. So basically the main difference between low-density and high ones, is the amount of chips on board. In most cases, low types have 8 - 16 and high ones have 4.

[rkawakami]

It's the amount of chips AND the total size of the module which determines if the module is low or high density. You need to know both in order to figure out what is what. Modules constructed with 16MB chips = low density; 32MB chips = high density.

And to be more precise, it's really the difference in the refresh specification that determines "densityness". 16MB chips uses 4K refresh while 32MB requires 8K refresh. But common usage to describe the difference between the two has come down to low vs. high.