Thinkpads Forum

I'm going to upgrade my T61 by putting 1 or 2 GB RAM (1 stick). Does anyone know any trusted seller on eBay so I can deal with?

Thanks

Diehard wrote:I'm going to upgrade my T61 by putting 1 or 2 GB RAM (1 stick). Does anyone know any trusted seller on eBay so I can deal with?

Thanks

I've got some extra Crucial 1GB sticks (tested in my T60p as well).

PM me if interested (and yes, I do sell internationally).


And yes - I have TONS of positive feedback.

i just bought 2G , paid $120 and suppose to get back $40 rebate .

Common Manufacturers:

* Micron Technology
* Samsung
* Kingston Technology
* Corsair Memory
* Mushkin

Which one is the best ?:

1. Corsair Memory

2. Mushkin

...

I'd say by far Micron (crucial) memory is superior. Basing this on my personal experienced plus 5 years in tech support. I can't recall one instance while I worked there when micron memory was at fault, whereas we had several other issues with non-micron memory. As for my personal experience, micron replaced a 5-year-old DIMM in my thinkpad 600 due to frequent bluescreening, even though it turned out to be the DIMM socket that was bad. I think they replaced the DIMM 3 times without so much as a complaint

we bought a 1GB strip from Crucial last week (for the T43). It was around $42 shipped. Plugged it in, no worries.

I've been upgrading all machines over the past few weeks. At these low prices it doesn't make sense to overlook this performance bump.

dalee18 wrote:I can't recall one instance while I worked there when micron memory was at fault, whereas we had several other issues with non-micron memory.

Then I should show you my Micron module which has a cold temperature problem . Once warmed up for a few minutes with a memory diagnostic or a successful boot, it works without any errors. However, plug the module in "cold", and by this I mean just sitting at room temperature (~65F) for about 10 minutes and memtest86+ finds a couple of bit errors within 15-20 seconds.

I should say that this is not limited to, nor indicative of, Micron memory. Every memory manufacturer has to deal with various issues when designing, making and testing memory. The datasheet parameters usually state that "normal" or "commercial" grade memory is guaranteed to operate between 0c and 70c (32F to 158F). However, due to the costs involved with testing memory at low temperatures, sometimes shortcuts are taken. Maybe the part is tested at a slightly higher (or lower) voltage or the timings are adjusted so that it stresses the part more than the specs indicates. It's usually assumed that these voltage and/or timing guardbands are good enough, based upon characterization data which is generally gathered for any new circuit design.

FYI, this is based upon my three decades in memory test engineering .

P.S. Does anybody in the Mojave desert want to buy a slightly used 128MB PC133 Micron module ?

Interesting stuff rkawakami... I wish I had your experience and knowledge!

This might be a dumb question but could the problem with your bad stick be a cold solder joint, lifted pad, or some other intermittent connection issue? Maybe there is a pin that only makes contact when the stick warms up, due to thermal expansion?

I remember I had a motor driver circuit board that would only work when warm, I reflowed all the pins and surface-mount parts and after that it never had issues again. I never was able to see any bad connection with my eyes or with a magnifying glass but after reflowing everything, it worked perfectly...

I suppose it could be possible that there's a bad solder joint somewhere on the module. I believe that the Micron module in question uses BGA packages so I can't visually inspect the soldered connections. However, based upon the failures I saw from memtest86+, I have to say it's just a problem with one or two bits that are failing, not an entire output pin or address range. I may be able to use our benchtop memory tester and find out exactly which memory is bad and then use the SMT rework station here at work and replace it, but frankly, I don't have the time or desire to do that right now. "Cold write" problems had affected one of our DRAM designs many years ago and also affected random single bits so that's why I suspect a part issue rather than an assembly problem. Historically it's been very hard to justify the time and cost to perform low temperature testing on 100% of the parts in production. Each "socket insertion" costs the manufacturer $$$ on an already razor-thin profit margin (at least for current products like DDR and DDR2). So instead, product engineers try to figure out the best simulation of cold temperature results by increasing the voltage or decreasing the timing (cold operation generally makes the part operate faster) and apply that at a room temperature test. It's not a perfect solution but one that has been used for many years. Since most "failures" or violations of the stated operational specifications are due to high temperature operation (parts slow down when hot), more consideration is given to making sure the part works properly at the upper end of the temperature range.

And getting back OT for a minute...

Diehard wrote:Does anyone know any trusted seller on eBay so I can deal with?

I've dealt with a number of eBay sellers for RAM. Even if you include the one seller who said they shipped them but to the wrong address and never recovered the package (and also who never responded to my requests for proof of shipping) and the couple of sellers who shipped defective modules (but was able to obtain a refund), then if you stick with sellers who offer at least a DOA (dead on arrival) guarantee or have a stated return/refund policy, then you should be fine. Inspect all modules when you receive them for any obvious physical defects (burnt parts, scorched or damaged traces on the edge connector, etc.). Run them to a memory diagnostic program (memtest86+ or PC Doctor) for a couple of hours (or three complete passes through all of the tests) before accepting them.

2GB with XP is a nice sweet spot

4GB with Vista is .... mandatory.

rxblitzrx wrote: 4GB with Vista is .... mandatory.

Oh BS.

Quit spreading FUD.

2GB is also a very nice sweet spot for Vista (of any flavor).

Got 2Gb module from Newegg.com 89.00 w/$20 rebate. Take out one of my 1gb mods and replace w/2.