T42 Fan replacement

[csabi27]

I have a T42:
ThinkPad T42 (2373-VKT)
Based 2373-CTO: P M 725(1.6GHz), 512MB RAM, 40GB 5400rpm HDD, 14.1in 1024x768 LCD, 32MB ATI Radeon 7500, 24x24x24x/8x CD-RW/DVD(slim), Intel 802.11b wireless, Modem, 1Gb Ether, UltraNav, Sec Chip, 6c Li-Ion batt,

I cannot find a fan to match up to my model code, 2373-VKT (or 2373-CTO ?).

Please help!
Thanks!

[Prodeje79]

I have a T42:
ThinkPad T42 (2373-VKT)
Based 2373-CTO: P M 725(1.6GHz), 512MB RAM, 40GB 5400rpm HDD, 14.1in 1024x768 LCD, 32MB ATI Radeon 7500, 24x24x24x/8x CD-RW/DVD(slim), Intel 802.11b wireless, Modem, 1Gb Ether, UltraNav, Sec Chip, 6c Li-Ion batt,

I cannot find a fan to match up to my model code, 2373-VKT (or 2373-CTO ?).

Please help!
Thanks!

I made the mistake of not opening mine first. Open it up and see if it is short or long. In addition you can get the FRU number. Also note if just the fan is replaceable. In hindsight, I will always just get a heatsink fan combo for easier install.
I replaced the fan on my t61 without issue, but I hated pulling it apart.
Just find your FRU and search on ebay. Find a seller with free return shipping. And awesome feedback.
Also plug your new fan into motherboard header to get before installing. My first was bad for my t61.

EDIT: first my first batch of fans, I used ny-citi-com on ebay.
With them you have to pay return shipping, even for DOA. Although it was cheap ($1.30), it still bothered me.
For the FRU 26R7860 T42 heatsink/fan i needed, I went with USA ebay seller thinkpan in San Diego , CA.
I even did the best offer to get it even cheaper. This thing 'appears' to be brand new OEM.
Plus I liked how they would pay for return shipping if DOA.

I could not find your model either, perhaps you can deduce by the video card? I say crack it open!

[ajkula66]

Radeon 7500 equals short fan.

[csabi27]

Radeon 7500 equals short fan.

Thanks for your quick answer!

[antelope]

I am getting "fan error" on normal boot-up. I've taken off the keyboard and thoroughly blown out years of dust etc but it still won't boot in normal mode (it will boot if I hit ESC on startup). This is now my daughter's computer and she doesn't remember it making any weird noises before it stopped working.

It seems the odds favor needing a new fan-heatsink but before I buy one I wanted to find out if anyone thought it might be:

A) Problem with the fuse for the fan since it wasn't making noise before failure. Issue discussed in this post but person with problem didn't seem to pursue the fuse fix.
http://forum.thinkpads.com/viewtopic.ph ... =fan+error

B) Some type of BIOS, firmware or fan control problem?

Also, any unhappiness out there with non-IBM/Lenovo fans?

BTW, my T42 model type is 2379-DXU.

[RealBlackStuff]

None of the above.
You need a new fan, the Long Fan M10, FRU 41W5204.
Try our Marketforum, then eBay, then IBM/Lenovo.

[antelope]

Thanks RBS!

[Orclas]

RBS basically answered your question, but to elaborate a tad...

In my experience all computer fans spin at power-on, fan control bios/software or not. They may just get a first power pulse, but they do. I believe this is so in order to prevent boot with broken fan, once your OS is loaded it's already halfway "too late" and at least an increased risk of component damage.

So, if you want to be dead sure, then just power on the computer with the keyboard removed. If the fan does not move at all, then it's surely a broken fan.

Did you buy any chance use compressed air and fire away on the dust in the assembly, without keeping the fan blades still while doing so? The fast moving compressed air may be an unintended coup de grace to an old and dying fan, if the fan is allowed to spin uncontrollably.

[antelope]

So, if you want to be dead sure, then just power on the computer with the keyboard removed. If the fan does not move at all, then it's surely a broken fan.

After cleaning under the keyboard - and the fan area in particular - I tried to start with the keyboard loose. No fan movement at all.

Did you buy any chance use compressed air and fire away on the dust in the assembly, without keeping the fan blades still while doing so? The fast moving compressed air may be an unintended coup de grace to an old and dying fan, if the fan is allowed to spin uncontrollably.

I did not hold the fan still. It was spinning WILDLY! I should have made a video - Fans Gone Wild . . . . Time to order a fan.

How much hard do you think could be done if the unit is run without the fan running but starting it using ESC? I had it running for awhile this way, mostly idling, and the fan / heatsink area didn't seem very hot. I'm wondering if my daughter could use it for a few days (carefully - minimum apps running) while I wait for a new part.

[ajkula66]

antelope wrote:

How much hard do you think could be done if the unit is run without the fan running but starting it using ESC? I had it running for awhile this way, mostly idling, and the fan / heatsink area didn't seem very hot. I'm wondering if my daughter could use it for a few days (carefully - minimum apps running) while I wait for a new part.

I would *strongly* advise AGAINST running any ThinkPad without a working fan for any amount of time.

[antelope]

I've found a fan unit from a 15" T43 being parted out on the forum (model 2687-D4U which I can't find on the Lenovo site). Is this the same fan part as what a T42 takes (2379-DXU)?

Seller is telling me it is the same part but the part numbers don't cross-reference on Lenovo's site. T43 (2687) shows FRU 26R9074 while 15" T42 (2379 DXU) shows FRU 13R2657 (original) or 41W5204 (current).

Does anyone know whether these are interchangeable? The price is good but if it doesn't work it doesn't help my problem. Thanks.

[ajkula66]

They ARE interchangeable.

[marnix]

Earlier in this thread "ranchmom5" showed a picture of her old and new fans and asked about the grey (AKA gray) pad in the middle of her new T42 fan assembly. "Johan" replied with:

The grey (thermal?) rubber-like pad, shown on the leftmost image you link to, is on the heatpipe side of the fan/heatpipe assembly, facing away from the CPU/GPU. This grey (thermal?) pad will therefore be positioned between the heatpipe and the keyboard. I have seen these gray upper-side (thermal?) pads on T43/p fans, but I don't recall having seen them on T42/p fans, so I will leave it to some more experienced ThinkPad'ers to comment whether to remove or keep this upper-side pad.

So here I am asking the same question. I have a new fan which I want to install. Actually I have already installed it twice and each time my T42p laptop would suddenly shut off after anywhere from 10 seconds to 3 minutes. I suspect that I didn't use a good thermal paste or used too much, so I'm going to try again with an expensive 99.9% pure silver thermal paste from Radio Shack (I suspect it is the same as the Arctic Silver I've been reading about). But I have this grey pad on the new fan. The grey pad is in the middle of the assembly, on the top (the side that would touch the keyboard). The grey pad is covered with a clear plastic. I can remove the clear plastic and feel the grey pad and it feels sticky, though it doesn't come off and stay on my fingers or anything. Should I leave this grey pad and clear plastic covering alone as I have done in my previous 2 attempts or do I remove one or both? I'm tempted this next time to just remove the clear plastic covering. I suspect that the grey pad insulates the heat in the fan assembly from the keyboard. I don't know if this is desirable or not. Maybe the bottom of the keyboard is supposed to help dissipate the heat. Hmmm. Since the old one didn't have it, maybe I should remove it.

In case you're wondering, this all started a couple of weeks ago with a "Fan Error" message at boot up. I couldn't feel or hear the fan running, so I assumed I needed a new fan. I ordered a new FRU 13R2657 fan from Ebay and have been trying to install it. I've tried twice already and am ready to try a 3rd time. My first try I cleaned the top of the CPU and GPU chips and installed the new assembly as is, allowing the thermal paste that was already on the assembly to mate with the CPU and doing nothing to the pink pad over the GPU. When that resulted in a system that would suddenly shut down/off after 2-3 minutes, I took it apart and tried a 2nd time. That 2nd time I cleaned up the old paste from the CPU, applied a little of the white thermal paste that came with the new fan to both the CPU and the GPU (I didn't know if it was necessary for the GPU, but thought it couldn't hurt). After this the laptop would stay up only 10-20 seconds before shutting off. So I've taken it apart again and cleaned all the old thermal paste off. I suspected that I used too much thermal paste and that the paste was poor quality (it was white paste that came with the new fan). Now I have a small $10 tube of 99.9% pure silver thermal compound from Radio Shack and am ready to try again. Well, I'm ready except for wondering about that grey pad with the clear plastic covering.

[ajkula66]

Leave the gray pad facing the keyboard alone, do not put any thermal paste on it, just leave it there after you've removed that clear plastic off of it..

Thermal paste is needed (one "grain-of-rice" sized drop spread with a credit card) on the CPU and if you choose to do so (I prefer to) on the GPU pad.

Good luck.

[marnix]

I just redid (for the 3rd time) the installation of a new fan assembly in my T42p Thinkpad. Alas, no change from the 2nd attempt . The system still powers off after about 15 seconds. The only changes between the 2nd installation and this last attempt was that this time I used a better (99.9% pure silver) thermal paste, using only a thin layer, and I removed a clear plastic cover that was over a grey pad in the middle of the assembly. I am ready to give up. Bummer. I've had it for 7 years. While it is by no means my primary computer or laptop, I had grown quite fond of it over the years.

Update: A couple of days after I posted the above paragraph I redid the fan assembly replacement a 4th time and finally it works! I can only guess that I was using poor thermal paste and then not enough, then too much, and finally just the right amount. I don't know what made me try a 4th time. I thought I had given up, but something made me try again. Glad I did.

[ajkula66]

Your thermal sensor might have gone haywire, as well as your CPU. I've seen both issues cause the type of behaviour that you're reporting.

What is the full model number of that T42p, 237?-???

[marnix]

My T42p is a 2372-KTU . Oops, that was supposed to be 2373-KTU.

[ajkula66]

If you have another CPU to test the machine with, that would be a good idea.

Should the behaviour remain unchanged with a different CPU, you're likely looking at a board replacement.

[Orclas]

Depending on your ambition level and dedication to try to fix your old faithful Thinkpad, I may add that a CPU can be had off ebay for $10-15 including shipping.

While you're at it, you may want to make sure that you get an as energy efficient and cool CPU as possible for the machine (with same performance), which is something in the direction of an Intel Pentium M Dothan range.

I once knew a tad about the details about the above, but am getting old and forgetful... Either google it or hope for ajkula or RBS (or some other TP encyclopedia-like person) to step in and give you the quick answer

[marnix]

I've never gotten that deep into fixing a computer, but, now that I'm retired and have the time, I'm interested in trying. I'll have to research what CPUs would work. I do not require performance equal to what I had before, but of course, it'd be nice. Can someone tell me how and where the high temperature is detected? Is it the CPU itself that does this? I'm just wondering if there's another component on or near the CPU that is measuring the temp. It'd be nice to know what my chances of success might be. If there is yet another component that could be causing my problem, then that reduces my chances that a new CPU would fix things.

Depending on your ambition level and dedication to try to fix your old faithful Thinkpad, I may add that a CPU can be had off ebay for $10-15 including shipping.

While you're at it, you may want to make sure that you get an as energy efficient and cool CPU as possible for the machine (with same performance), which is something in the direction of an Intel Pentium M Dothan range.

I once knew a tad about the details about the above, but am getting old and forgetful... Either google it or hope for ajkula or RBS (or some other TP encyclopedia-like person) to step in and give you the quick answer

[Orclas]

Something tells me that you wrote the wrong model number. 2372 is an X40, whereas 2373 is indeed a 42p and with the following spec for the KTU version:

ThinkPad T42p (2373-KTU)
P M 755, 1GB RAM, 60GB 7200rpm HDD, 14.1 SXGA+(1400x1050) TFT LCD, 128MB ATI FireGL T2, CD-RW/DVD-R Multi-Burner(slim), IBM 802.11a/b/g wireless, Bluetooth/Modem, 1Gb Ether, UltraNav, Sec Chip, 9 cell Li-Ion Batt, WinXP Pro

Pentium Mobile 755 ("P M 755") is indeed a Dothan processor so you're already good from that perspective (I myself had a so called Banias range in my T40, which I exchanged for a Dothan since it's cooler and faster). As far as I know, you can move a tad up and down the performance scale and still be ok, they come in the versions M 710 (1.4 GHz), 715 (1.5 GHz), 725 (1.6 GHz), 735 (1.7 GHz), 740 (1.73 GHz), 745 (1.8 GHz), 750 (1.86 GHz), 755 (2.0 GHz), and 765 (2.1 GHz).

I would assume all of the above would fit your computer, but unless you're after minimizing computer heat and noise, you should probably not go too low on the scale.

As for where and how temp is measured and your chances of success, you'll have to hope for some peeps who really know stuff to pop by.

[antelope]

Update on my situation: today I received and installed a used long fan from a T43 (FRU 26R9074) into my T42 (2379DXU). Note that this isn't the stock original or replacement part number but as per Akjula's reply above (and from seller) it does seem to work fine (five minutes so far - my daughter will kick it into full-time use tomorrow). The only thing I wonder about is if it is louder then the original fan when the fan kicks in.

A tip regarding separating the fan/heatsink from the GPU and CPU: While the fan and CPU separated easily (located between the three fan screws) the bond between my original fan and the GPU was very stubborn (this is the far right end of the fan directly above the touchpad). After trying to separate the two with what I thought was considerable force (trying to get a smooth butter knife or sharp putty knife between the two) I found a tip from another TP fan-related "pink pad" thread that suggested trimming off the hardened black goo around the edges of the pink pad (just under the copper fan base sheet). I did that using an Xacto knife and then it was much easier to push the putty knife between the pink pad and the light gray top of my Radeon 9600 GPU. I also removed my wireless card to get a better (lower) angle on the putty knife in order to avoid gouging the GPU (I pushed the putty knife in from the front of the unit, not the right). Anyway, I thought I would mention these details in case it helps someone else who is having the same issue and concern.

Thanks to everyone here for their helpful comments. I love the TP community!

[Orclas]

Congrats ante!!

As far as I know, long fan is quieter than the short, at least it runs less (due to higher efficiency).

Given that you're handing it over to your daughter I would, if I were you, do some quick testing to see that everything is ok. I would recommend the following:

1. Download and install Speedfan, it's a great tool to read various temp sensors on a computer (http://www.almico.com/sfdownload.php)
2. Download Prime95, which originally is a clustered (or whatever the word is) effort to find new prime numbers. The overclocking/tweaking community has found another great use for it, namely to "stress test" a computer (CPU, RAM and indirectly cooling). You find it here: http://www.mersenne.org/freesoft/
3. Run Prime95s stress test, I believe they call it "torture test". Choose the version for "max heat".
4. If the CPU temperature goes above 70-80 degrees C, then it's time to abort (the CPU can take up to 100 degrees, so you're still safe)
5. Let it run for a few minutes to monitor fan kicking in and /hopefully/ pushing the temperature back down

Edit: For good measure, and being over obvious, make sure that you get a sensible and proper reading for CPU temperature before starting Prime95. After boot it should be somewhere 30-45 degrees depending on ambient temp and stuff.

[marnix]

Orclas wrote:

Something tells me that you wrote the wrong model number. 2372 is an X40, whereas 2373 is indeed a 42p and with the following spec for the KTU version:

ThinkPad T42p (2373-KTU)
P M 755, 1GB RAM, 60GB 7200rpm HDD, 14.1 SXGA+(1400x1050) TFT LCD, 128MB ATI FireGL T2, CD-RW/DVD-R Multi-Burner(slim), IBM 802.11a/b/g wireless, Bluetooth/Modem, 1Gb Ether, UltraNav, Sec Chip, 9 cell Li-Ion Batt, WinXP Pro

You were quite correct. I've edited my post to show the correct 2373 model number.

I might go ahead and try changing out the CPU. I haven't yet decided if I'll go for the old 2Ghz CPU or a slower one. A slower one might allow me to use the laptop on my lap for a longer time. But fast is always nice. I just hope changing out the CPU will fix my problem. Well, it will be good experience for me in any case.

[Johan]

@ marnix:

If you wish your T42p to run cooler/more quiet/longer (on battery), then I suggest you see this post which will enable you to install and fine-tune the fantastic, free program Notebook Hardware Control

Using NHC (Notebook Hardware Control) you may force your T42p to run permamently using the lowest possible clock-frequency, which is 600 MHz - this will make the ThinkPad run cooler and longer (the latter owing to the reduced power consumption). I cannot emphasize enough what a highly valuable tool NHC is for e.g. T4x/p laptops - get in NOW and live happily forever after!

Johan

[Orclas]

@ marnix:

If you wish your T42p to run cooler/more quiet/longer (on battery), then I suggest you see this post which will enable you to install and fine-tune the fantastic, free program Notebook Hardware Control

Using NHC (Notebook Hardware Control) you may force your T42p to run permamently using the lowest possible clock-frequency, which is 600 MHz - this will make the ThinkPad run cooler and longer (the latter owing to the reduced power consumption). I cannot emphasize enough what a highly valuable tool NHC is for e.g. T4x/p laptops - get in NOW and live happily forever after!

Johan

Above is quite correct, I am also myself a very happy user of NHC (mostly as a part of achieving an absolutely silent TP). I would however rather start with undervolting the processor and use dynamic CPU speed (which in my case makes the CPU step between 600 MhZ and 1,5 Ghz depending on load). 600 MHz doesn't quite cut it for some of the modern day surfing, although it does make for the absolutely maximum battery time.

What I -really- love with NHC is the smart fan management, particularly when on DC. At least my T40 has a fan which runs just about permanently when on DC (and it isn't quiet), probably due to some over cautios bios fan scheme. A first try with another fan management software just led to a constant on-off, since it only facilitated one single threshold. NHC can be set to have a fan on at temp x, fan off at temp y to avoid this (in addition to detailed setting for the different fan speed levels low mid high max). In practice this means that I have my settings to something like "Fan low on = 48 degrees" and "Fan off = 45 degrees"*, i.e. once the fan starts, it cools the CPU down enough for it to not have to run again for a while once off.

To sum it up (about NHC), it is a vital part in my succesful quest for a silent TP since:

- it allows me to undervolt the processor
- it provides a very well functioning speed stepping module ("performance" when needed, otherwise energy/heat efficiency)
- it allows me to control when and how the fan kicks in, in the case cooling is indeed needed

Tempted?



* If anyone wonders about the relatively low threshold for fan to start, it's because other parts/general interior of the T40 needs a bit of ventilation/indirect cooling during longer usage sessions (particularly the WLAN card which gets hot).

[marnix]

I got my T42p working again! After 3 failed attempts, I had almost given up. This all started with a message "Fan Error" and in inability to boot. I couldn't hear the fan running, so I figured the fan had died. I ordered a new fan on Ebay, which arrived about 6 days later. For my the first attempt to install the new fan I used the thermal paste that was already on the new fan assembly (a grid of little dots). After that, the system would shut down after a minute or two. For the 2nd attempt, I took the fan out and applied some of the thermal paste that was included separately in the package that the new fan assembly came in (white stuff that looked like caulking paste). Now the system would shut down after 10-20 seconds or so. For the 3rd attempt, I got some good quality Arctic Ice thermal paste I had read about. I used a small amount that I deemed to be about the size of a grain of rice. No change. System would still power off after 10-20 seconds. I was already looking around to see if there was a cheap used T42p I could buy to replace this one. But really, I don't *have to have* this laptop. I've just grown fond of it and want it around doing little things for me here and there. I didn't think I'd try fixing it again, so I just kind of fumed inside waiting for myself to get used to the idea that I didn't have this laptop anymore and thinking about my options for possibly replacing it. Then I decided to just try one more time. This time I put on about 2 or 3 times as much of that Arctic Ice thermal paste. First a bit and spread it around to cover the top of the CPU, then a 2nd amount of about equal size in a little lump right in the middle. Put it all back together and booted up off of a USB flash drive loaded with Knoppix Linux. It worked! Man was I jazzed! It's been up and running for a couple of hours now. For now I did go into the BIOS and set the CPU to run at its slowest rate. I used the Knoppix/Linux 'sensors' command to see temps and fan speed while I made the CPU to some heavy math work. Temp went from 40C to 80C. I haven't put the hard drive back in yet, but I assume/hope that's not going to make a difference. Once I have the system working OK off of the hard drive, I'll try resetting the BIOS to allow the CPU to run at max speed. Oh, in the meantime, one of my keys became sticky. I may have to take the keyboard out one more time and check/clean around that key (the 'C' key). I'll also see about that NHC software if/when I boot up into windows.

Woo Hoo!!

[Orclas]

Congratulations!

Nice feeling to get things to work. I wonder if there might have been a slightly-larger-than-usual gap between the fan assembly and the CPU which you managed to bridge with the cooling paste. Or the way you applied the paste worked better on your machine (there are pretty much two schools when it comes to applying thermal paste, the lump school and the spread thin layer school).

Let's hope things stay nice and stable

[marnix]

Yep, my T42p is still up and running. In the meantime I found the cause of the sticky 'C' key. It was due to that weird sticky little grey pad that was in the middle off the new fan assembly. I didn't have such a pad on my old fan, but when I asked about it in this forum, someone suggested I just leave it (except for the clear plastic cover). Anyway, this little pad has two cutouts. The cutouts look like little barbells. The grey material was still inside the cutouts, but could easily be picked out and removed. I have no idea what that grey pad is for or why there are those two little barbell-like things in there. One of those little barbell-like things had managed to come out of its cutout and was pushing against the bottom of the keyboard underneath the 'C' key. I'm guessing that it squeezed some of the sticky stuff through one of the tiny holes in the bottom of the keyboard and thus making my 'C' key stick. I removed that grey sticky pad, cleaned the keyboard bottom with isopropyl alcohol, and put everything back together. All is working. Whew

[pafka99]

Hi all

I'm sorry for this silly question. The SN of my T42 is L3-K6219, type 2374-Q16 (Pentium M 1.7GHz, ATI Mobility Radeon 7500).

I didn't find the suitable FRU for this type, type number doesn't exist :-/ http://support.lenovo.com/en/documents/migr-46474#18
Please, which fan (FRU?) fits to this T42?

Thanks a lot for your answers.
P.