Thinkpads Forum

I have a T61 that needs its motherboard replaced. How can I tell before purchasing motherboard on ebay?

Cheers, thinkpadcollection.

Systems manufactured Aug 08 or later will not have affected chips in them; check the date on the serial number label on the bottom of the PC. You can also check the date code on the chip itself - it is in the format YYWWA02 with YYWW being week and year. Some information I've seen (I can't, unfortunately locate where I read it) suggests chips from week 30 or so of 08 are of the revised flavor. I don't remember if this refers to the date code on the chips... or when motherboards were manufactured for Lenovo with chips that were revised.

My oldest T61p that I bought new has a GPU with a 3107 date code. This one started showing signs of early failure in eh, 2011-2012 or so - but the computer runs normally under average load. I bought another motherboard a year or so ago with a 1208 GPU (with a build date of 5/08)... no issues under any circumstances thus far...

thinkpadcollection wrote: How can I tell before purchasing motherboard on ebay?

I'd *strongly* advise against purchasing a *61 series planar with nVidia GPU on feebay, or from an unknown source in general. But that's me.

The date code on the laptop is in YY/MM format, the code on the chip is YY/WW format Y=year, M=month, W=week.

Laptop date of 08/08 or newer (this is the last month of general production so few have later dates), which corresponds with a chip date of 08/20 to 08/30, but the chip date isn't conclusive because it only signifies the date it left production and all evidence suggests they were produced on many production lines in many factories worldwide and the updates were gradual. There is also pretty conclusive evidence that they didn't dispose of the chips that were known to be unreliable but after negotiations with lenovo they were supplied with the improved chips that went into production models in August 2008, but chips dated with the same date range in other products were found to have failed. The only way to be certain is to pull the board yourself after confirming it's an original 08/08 and that the board was never replaced.

I agree with George, if you're looking for one on ebay you could be opening a can of worms as there are many boards that have been reflowed and baked sold on ebay. I can usually get genuine 08/08 boards if you're interested in one, or in some cases even a new NOS board which are available for a couple models.

If you do source one on ebay I'd test it as much as possible, a board that's been reflowed will have fractures in the gpu circuits that often manifest in temp fluctuations and if you look at a gpu temp graph when stressed you will often see a jagged graph, anywhere from a jagged line to one resembling a heart monitor, where a good sound gpu will produce a line that's flat and smooth as glass.

The real problem is that a reflowed board could work for several weeks in which time you'd have no recource dealing with ebay, and I've never seen a reflowed board last longer than a few months.

You could always just "upgrade" to an Intel graphics board.

I've seen some Nvidia boards on Ebay that the seller claims are good and free from the defect, yet show obvious signs of having been fluxed and cooked.

Qing Dao wrote:You could always just "upgrade" to an Intel graphics board.

True, and these will suffice for most people's needs - presuming any *61 series machine would do the job to begin with.

Reason is interested in nvidia GPU motherboard because of bios mod and motherboard mod to take penryn 1066 fsb but downclocked to 800fsb to run at 2.0 to 2.2GHz depending on CPU choices: T9800, P9600 or P9700 for much longer battery runtime. Doing so makes me concerned with intel's x3100 GPU performance with these processor choices.

Cheers, thinkpadcollection

thinkpadcollection wrote:Reason is interested in nvidia GPU motherboard because of bios mod and motherboard mod to take penryn 1066 fsb but downclocked to 800fsb to run at 2.0 to 2.2GHz depending on CPU choices: T9800, P9600 or P9700 for much longer battery runtime. Doing so makes me concerned with intel's x3100 GPU performance with these processor choices.

I'm sorry, but that made no sense at all. You want to downclock for battery life, but run a nVidia GPU? First off, downclocking the maximum performance of the CPU will only save you power if something is hogging CPU power, and when this is the case you won't be happy with the battery live either at 2 or 3 GHz. Secondly, the intel GPU will give you much better battery life than nVidia.

TuuS wrote:I've never seen a reflowed board last longer than a few months.

Technically, that is incorrect. All your thinkpad mainboards have been reflowed at least once during manufacture. Double sided boards are often reflowed twice (but in that case the side with the large BGA's would likely go last). It may be more fair to say you have never seen a re-worked GPU that kept working.

Out of curiosity, why would people do this anyways? Are they unaware the nVidia problem is on-chip? Or are they replacing the GPU with one from another old laptop (re-balling it with amateur-hour process)?

I bought a T61 8889-B35 from eBay, with SXGA+ display, complete working machine from eBay. I want to install OS X Mavericks on my FrankenPad, I just want to try to see how it performs, so I took a gamble. The ad showed very little detail with one small photo, so I could buy it cheap. I had to ask the seller which GPU it had, because it wasn't mentioned.

When it arrived the date on the bottom is 08/05, so I thought bad luck, I will just use it until it fails on me, en then I will reinstall my 42W7872 Intel X3100 board.
However, today I opened the laptop and took out the system board so I could check the Nvidia chip. The motherboard FRU is 44C3924, and the chip date is 0809A2... So this should be the first week of March, 2009

I think I am very lucky

Backslashnl1 wrote:When it arrived the date on the bottom is 08/05, [snip]
The motherboard FRU is 44C3924, and the chip date is 0809A2... So this should be the first week of March, 2009

Sorry to burst your bubble: As TuuS explained above, the date code for the Nvidia chips is YY/WW, so your chip was produced in the 9th week of 2008.

theterminator93 wrote:Systems manufactured Aug 08 or later will not have affected chips in them; check the date on the serial number label on the bottom of the PC. You can also check the date code on the chip itself - it is in the format WWYYA02 with WWYY being week and year.
[..]

Guess the terminator was wrong ?
Perhaps it was too good to be true then

Yeah I goofed apparently on the format of the date etched on the die. YYWW, as it turns out. I've edited the original post to correct the mis-information.

Also keep in mind - just because a chip was manufactured during the defect period doesn't mean it WILL fail. Prevent excessive heat, reduce the number of heat cycles, and it should outlast the usefulness of the machine. Both my T61p laptops have "defective" FX 570m (the hotter of the two) chips and are still running - almost 8 years old now.