Motherboard specs for a T40

[SkipHK]

I have a T40 2373 72U that, in earlier years had a motherboard fail and replaced under warranty. It took a couple of motherboard replacments before they got one that worked for more than a couple days. The video chip was what failed requiring the replacement. This was like three years ago. Recently it has failed again with the same symptoms. I want to replace the motherboard again (myself) so I can use the laptop as a backup.

The manual for this model lists an FRU part number 91P7716. However, the part number under the memory card on the bottom shows FRU 39T5400 was installed back with the warranty work a few years back. One supplier recommended a 39T5448 which comes up for a T42 model.

The price difference for these motherboards from various sources is significantly different. Many folks state they are interchangable. My questions are... are they truly interchangeable? ... and, what is the differences in these motherboards.

Can anyone telll me the differences or point me in the direction of a source for specs.? I haven't been able to zero in on actual board specs for these.

Skip
hughk43@verizon.net

[ajkula66]

Start here, although not everything is covered:

http://www-307.ibm.com/pc/support/site. ... 46474.html

[scr71822]

In my experience the motherboards from r50 r51 r52 t40 t41 t42 t43 all have the same dimmensions. I have installed a r51 board in a t43 chassis right now. I have put T41 boards in T40 and T42. What you need to be concerned with is the heatsink requirements for the Video Chip mostly. There are many different heatsinks out there for the different ATI and intel video chipset boards. The only other port that may or may not be accessible is the IEEE1394, as most of the 14.1in t4x series do not have the port available in the case. You can still install the motherboard though.

[underclocker]

To avoid the same failure in the future, you could use an Intel GPU based R51 motherboard, see this link for more info --> http://forum.thinkpads.com/viewtopic.php?f=2&t=65505

Several of the sticky threads at the top of this forum relate to the GPU issue.

[ThinkPad560X]

Would your T40 freeze if moved? Mine does it and got tired of keeping it on the table so bought a new T40 motherboard and now started to do it again, Same thing as what my first board did.

[SkipHK]

Mine does not freeze.... it goes into a blue screem error indicating the Radeon 7500 is causing th problem. I believe it is the vidoe chip on the motherboard. I amd trying to find out more about alternative video chips and the differences in the system boards. One person mentions a heat sync on the vieo board. i've seen the CPU heat sync and pulled it and put new dialectric between th heat sync and CPU. I've not opened it up enough to see the video ship... I wouldn't know what it looks like.

If anyone can talk more about the video chip please do so.

Skip

[underclocker]

I am trying to find out more about alternative video chips and the differences in the system boards.

Bottom line, the 2373-72U has the most basic (a.k.a., entry level) T4x GPU, the 32MB ATI 7500. As mentioned above, any T40, T41 or T42 mobo will work. It will be a direct swap. With the T41 & T42 mobos, you could use PC2700 vs. PC2100 memory, but it's not necessary. With the higher performance GPUs (all but the ATI 7500), you should use a "long" fan (a high performance fan with more copper that covers the GPU). The only way you'd find a downgrade from the board you have now is if you find one with the ATI 7500 and only 10/100 Ethernet, yours is 10/100/1000 Ethernet. (For the purists, I have read that IBM sold 16MB ATI 7500 T40 mobos outside the U.S., but I've never seen one.)

T40, T41 & T42 options include (again, some are 10/100 Ethernet, some 10/100/1000 Ethernet);

32MB ATI 7500
64MB ATI (9000) FireGL
32MB ATI 9000
64MB ATI 9600
128MB ATI (9600) FireGL T2

There are many, many posts on this topic. The forum search feature works very well.

You can also use mobos from other models, T43, R52, R51, R50, but it gets a little more complicated. You can search for much more info, including options for repairing your existing mobo.

Good luck.

[SkipHK]

You guys sure have me going a bit in circles... If I summarize the info you all noted it sounds like I should opt for a little higher end motherboard. If I do this I might end up with a different vieo chip...I think. Based on my past experience this doesn't hurt my feelings one bit.

Not being familiar with this level of parts detail I'm trying to come up with a way to understand the the FRU numbers on the motherboards I see listed at various places for sale. I certainly don't want to go backwards in CPU speed. I alos have 1.5 ghz of memory (I think 2100) I'd like to reuse or build out to 2Ghz depending on what I find.

When I see the codes after 2373 like 72U or other codes my take is that implies like 1.3, 1.4, 1.5, etc processor speed.. is that correct? Is there a way to see what the codes mean? ... perhaps a web page... can't find board specs on Lenovo.

How can you tell with a board number what the video chip is you are getting? ... For example a 91P7998...

Skip

[rkawakami]

You can plug in a Thinkpad TYPE number (e.g., 2373-72U) at this site's "Product number" field:

http://www-307.ibm.com/pc/support/site. ... OME-LENOVO

and get something like this in return:

Product: ThinkPad T40 2373-72U [change]
Operating system: All [change]

Original description: P M 1.5GHz, 256MB RAM, 40GB 5400rpm HDD, 14.1 XGA(1024x768) TFT LCD, 32MB ATI Radeon 7500, 16x10x24x/8x CD-RW/DVD(slim), Modem(CDC), 1Gb Ethernet(LOM), Intel 802.11b Wireless(MPCI), Secure Chip(TCPA), UltraNav, 6cell battery, WinXP Pro

This will be the configuration of the system as it was delivered from the factory. Note that items such as the quantity of memory or the hard drive may have since been changed.

As far as there being a systematic code used to define the three characters after the 4-digit TYPE, I don't believe that there is one. The best thing to do when confronted with a system type is to plug it into the site I listed above or consult the Hardware Maintenance Manual. The one for the T40-T42 systems is here:

http://www-307.ibm.com/pc/support/site. ... MIGR-46464

For checking up on the components used on any particular motherboard (the video controller, in particular), you might have some luck by checking the HMM. Unfortunately in this case, 91P7998 is not listed in the T4x HMM but a Google search seems to imply that it has a 32MB ATI 7500 chip. I also believe that most (all?) Thinkpad systems, any TYPE number starting with a "1" has Intel integrated graphics, whereas models starting with "2" will have discrete graphic controllers.

[SkipHK]

OK... I finally removed the motherboard and ready to pick one up. Some of the T40 motherboards have a 1.3 mhz, 1.5 mhz, and 1.7 mhz processors as I have concluded. I am fairly sure the part number for the mobo indicates which speed it can handle. The 91P7716 (my original) and the 39T5400 (installed under warranty years back) I assume met the 1.5 mhz original spec for the 2373 72U.

I do understand that physically many will fit. I find many other numbers and still wonder where the best place to get confirmation I won't go backwards with processor speed.

I appreciate all the responses and hope input on this specific input might be available from someone.

Also, I have the 14.1" screen (diagonal measurement I presume). The T40 could come with a 15.1" screen back then and wonder if the base and motherboards are physically the same dimensions. My 14.1" doesn't have much left in the perimeter to accommodate another diagonal inch. Any comments on this is appreciated.

Again, thanks for your patience.

Skip

[ajkula66]

No such thing as "handling speed"...any T40/41/42/p motherboard will be able to use the same range of processors, the fastest one being PM 765 which is Dothan 2.1 Ghz.

Differences between boards include, but are not limited to: type of GPU used, Gigabit Ethernet vs. 10/100, security chip, etc.

T40 only came with a 14" LCD, no 15" LCD were present prior to T42/p models in this range.

Having said that, all T4x motherboards are the same size regardless of the screen size.

[RealBlackStuff]

In other words, as long as the replacement motherboard is from a T40-T41-T42-R50-R51, you can transfer your existing CPU, RAM and wifi card to the new one.
Worst case, you may also need to buy the larger CPU cooler.
Do not buy a mobo from a T43 or R52, as these are not compatible with your CPU and RAM!