Novel, Silent and Cheap way to cool a Tablet. (Tecra M4)

Discussion in 'Hardware' started by thatcomicsguy, Nov 15, 2009.

  1. thatcomicsguy

    thatcomicsguy Scribbler - Standard Member Senior Member

    Messages:
    2,024
    Likes Received:
    1,064
    Trophy Points:
    181
    Okay, so I just ordered a nifty Tecra M4 from eBay.

    I love my little M200, but the siren call of a 14" screen at 1400 x 1050 dpi proved impossible to resist. . . I gave in. (I also found one for a very good price. $200 entirely tricked out? Sweet!)

    And I know. . , the over-heating GPU problem. Type, "Tecra M4 gpu overheating" into Google and weep. The M4 remains a fantastic Tablet PC, top in its class, with that one serious flaw.

    --Now, the one I'm picking up is an end-of-corporate-lease refurb. Probably used by some dude in a cubicle for very boring work and no 3D gaming which would have sent the GPU up into the red zone. In any case, the screen is still working properly. I however, am planning to put it through the Photoshop paces, and given what is known and reported about this model, I'd be foolish not to expect problems.

    So I've started planning my attack on the dreaded overheating issue. I looked at several options, from regulating the voltage, to performing open-heart surgery. --From the images of the guts of an M4, it looks as though it wouldn't be difficult to move the hard drive into the battery bay and install another fan in the hard drive bay, which being right next to the offending GPU would allow a secondary air-flow directed at the little monster. There's an option for a secondary slim-line battery which fits into the DVD/CD bay, so I could still benefit from having a battery in place. . . but with a third fan. . . (there are already two fans native in the M4!), it would be a very noisy machine. . . Anyway, that was my basic idea.

    Updated Note: As freedomeagle pointed out below, (thanks!) there is a fix out there whereby the GPU fan can be hard-wired directly to one of the USB 5 volt power sources on the board, so that it remains permanently on. This sounds like a fairly simple solution, far less complicated than installing a whole new fan! I've been trying to find somebody who has performed this fix long enough ago to be able to report on its success rate and what it's like to be working with a system that is always generating noise. I've not heard back yet from anybody on this.

    Anyway, it looked like these were my options and for the sake of the 14" screen, I was willing to work with them. But then I had one of those non-linear "Bing" moments which stopped me cold. (And which is the point of this whole post). --I thought to myself, "No way. It can't possibly be THAT easy. . . Can it?"

    Well, guess what? It is.

    Check this out. . . For $20, you can buy a silent air pump designed for a fish tank. But instead of running an air hose into a tank of water, one can simply run the hose directly into the guts of the computer and aim a constant stream of air at the heat-happy GPU. Problem solved.

    This is the air pump model I'm looking at, available at any pet store. . .

    Consulting the specs listed on that page, the second-to-smallest one, the "Rena 100", moves 32 gallons of air per hour at 2.2 psi.

    I pulled out my old and clunky air brush compressor, blew off the dust and ran some tests to see what 32 gph at 2.2 psi was like. I was very satisfied. It's more than enough to tame a hot micro chip. It'll be over-kill, actually. With luck and a bit of careful placement of air hoses, the dual fans in the machine may never turn on again.

    The "Rena" is a French-built compressor with silent running being a key feature of its design. After reading a few dozen comments and reviews from fish-tank enthusiasts, I've learned that the thing can run for years non-stop in almost complete silence. And best of all, it'll be off somewhere under my desk, so the computer itself will be basically silent.

    Now, of course, if you're planning to take your Tablet PC on the road, hauling along a fish tank accessory is. . , well it's just silly. But if you're like me, and you are using your Tablet PC like a Cintiq and you have it permanently mounted to your desk or drafting board, then this solution kicks some pretty serious arse.

    I've always found that one of the coolest ways to solve problems is to cross-pollinate technology from entirely unrelated industries. In this case, I'll be heading off to the pet store for an inexpensive air pump and fifteen feet of hose for my computer. --I'll just perform some simple surgery on my Tecra M4 when it arrives, install a hose, and voila! I'll have a nice, air-cooled system. Not in the same league as the overclocker crowd, but compact and silent; not bad for a laptop.

    (Also. . , I wish I'd thought of $20 fish tank air pumps back when I bought my first air brush. The air compressor I bought ran me close to $500, which for an 18 year-old living in the late 80's was a significant bit of cash outlay. But wisdom comes with age.)

    Anyway, I'll post some pictures when I rig it all together.

    I'll be building a new skirt for it like the one I have on my M200, so there's a bit of work involved, but I'm looking forward to having a nice, quiet, air-cooled 14" digital drafting board.

    Cheers!
     
    Last edited by a moderator: May 18, 2015
  2. NamelessPlayer

    NamelessPlayer Scribbler - Standard Member Senior Member

    Messages:
    898
    Likes Received:
    60
    Trophy Points:
    41
    Interesting solution, but if I had a Tecra M4, I would definitely be taking it to university and back. Thus, the cooling solution would have to be internal.

    I really want to know where you got a maxed-out one for just US$200 on eBay, though. That beats even my TC1100-for-under-US$200-shipped deal, and I still had to upgrade the RAM and hard drive! (It did have the GeForce Go6600 rather than the 6200, right? The more GPU power, the better, so long as it doesn't overheat!)
     
  3. freedomeagle

    freedomeagle Pen Pal - Newbie

    Messages:
    92
    Likes Received:
    0
    Trophy Points:
    16
    I think (think!) I read that the fan on an M4 doesn't receive enough voltage to spin fast enough on the GPU to cool it properly. I think (think!!) I read that someone attached it to another part of the motherboard... here's the post, I found it.

    http://www.tabletpcbuzz.com/showthread.php?t=35983
     
  4. thatcomicsguy

    thatcomicsguy Scribbler - Standard Member Senior Member

    Messages:
    2,024
    Likes Received:
    1,064
    Trophy Points:
    181
    I got it from this guy. When I last looked, he still had half a dozen or so M4s of the same quality. I won the bid and simply asked him after the sale how much he'd charge to plug in another stick of ram. He quoted me a price and I paid it. To be fair, though, I didn't include the shipping charge, and when it crosses the border, I'll be nailed with a customs tariff in the neighborhood of $50 or so. Still, all told, it's less than I paid for the 12" Portege M200.

    I find when I'm in the market for something and I'm not in any rush, I'll just spend a few minutes now and again checking eBay during the week and just bide my time until the perfect item pops up. In this case, the vendor flooded the market by putting his entire stock on eBay all at once, all at sub $200 starting prices. And he did it at a time of year when most students have already bought their laptops for university, so the market was slack. He seems to have a good supply pipe which operates beyond the bounds of the eBay environment. I should mention that he was a decent fellow to work with and I sincerely hope he was covering his costs.

    It's a bit of a game. --At this point, I've spent enough on these old Tablet PCs to have purchased one of those grand Cintiqs. (I've given two laptops away in the last six months to other creative people who didn't have the resources to get their own and who I thought could genuinely benefit from this cool technology.) Anyway, this is much more satisfying. Besides comics, I've always been a total DIY geek. I find I draw better when I exercise my mind in other ways, particularly with regard to these kinds of dorky engineering projects. (I'm going to have a computer hooked up to a fish tank air pump for goodness sake! Ha ha!) --I remember reading once, long ago (before Phantom Menace), when Lucasfilm was hiring on the first wave of computer animators that they didn't want people who could JUST animate. They wanted people who also enjoyed re-building motorcycle engines or who had similar hobbies. Knowing how stuff works makes you a much better artist. I try to live by that ideal.

    Cheers!
     
    Last edited by a moderator: May 18, 2015
  5. dtwn

    dtwn Pen Pal - Newbie

    Messages:
    28
    Likes Received:
    0
    Trophy Points:
    5
    I've actually purchased from this seller as well. My M400 arrived D.O.A and would power on only intermittently and when the screen was set at a certain angle. The lid was very loose in its mount and the machine would shut off whenever it was changed into slate mode.

    However, Craig was extremely helpful and responsive. Was willing to work with giving me a refund, however, he mentioned he was running low on M400s and could not give me an exchange.

    I did, however, manage to pick up a much better spec'd M400 for about $20 more elsewhere so I'm quite satisfied.
     
  6. thatcomicsguy

    thatcomicsguy Scribbler - Standard Member Senior Member

    Messages:
    2,024
    Likes Received:
    1,064
    Trophy Points:
    181
    Yeah. I've got my fingers somewhat crossed on this as he seems to ship a few more problem units than the more established suppliers, but the overwhelming bulk of his feedback looks very positive with the few complaints all looking like they'd been dealt with fairly. Either way, I'll report back here and let everybody know how it turns out.

    Cheers!
     
  7. thatcomicsguy

    thatcomicsguy Scribbler - Standard Member Senior Member

    Messages:
    2,024
    Likes Received:
    1,064
    Trophy Points:
    181
    I've been meaning to post for a while on this, and finally found the time, what with deadlines met and the holidays upon us. . .

    So that Tecra M4 showed up just fine. It was a bit of a beater, with a few wear problems, but on the whole, it was a fully-functioning M4. I was pleased. (Also, the cross border tariff pirates didn't ding me, so all in all, it turned out to be a very inexpensive acquisition.)

    First of all, it needed a new screen. I don't know what other M4 users experience, but I found that the screen it came with had too much flex; that is, when drawing with normal pressure pretty much anywhere toward the center of the screen, caused the cover to flex downward and touch the LCD. This, of course, causes that annoying rainbow effect, and to such a severe degree which basically made it unusable. --I should note that while a very hard press can affect my Portege M200 in a similar way, it is by no means as severe and it usually never happens under normal use. --I've not heard of anybody else complaining of this 'feature' before on the Tecra M4, so I assume it was due to the screen on this machine having become misshapen over its use life, although I couldn't see any obvious deformation when I took it apart for examination.

    Now, I'd earlier that week made a bunch of picture frames for a gallery showing I'll be having of my paintings in the new year, and during that process, I'd become familiar with the local glass cutter/supplier. Glass is very cheap, so I thought, "Hey, I'll just get a piece cut to the right dimensions, replace the plastic screen cover with it and see how that plays out."

    --So for about $10 I got a piece of mat-finish picture frame glass (they achieve the mat finish via sand-blasting on the manufacturing side), which offered a nice, smooth work surface and no-glare. This, however, didn't work out. While it provided a lovely work surface which was perfectly rigid, the sand-blasted glass caused too much distortion to the LCD images. The effect was rather like the graininess one experiences with the M200 screen cover, but at two to three times the effect, rendering it unusable. Too bad.

    So I tried just a regular sheet of glass, and this works out very well. You get the full brightness and clarity of the LCD, making the M4 screen a beautiful thing indeed. The drawback, of course, was that it wasn't mat. It can cast a glare under bright lights, and skin has a tendency to 'stick' rather than glide across the surface. However, when put to practical use, it seems to not be an issue. In the winter, with the humidity down to nothing, the air and my skin are quite dry, so my hand does indeed glide around the surface with little resistance. I was able to do a couple of drawings quite comfortably, and the lighting conditions in my studio are such that glare is never a problem. I don't know how well it will perform on a humid Summer day, but I was experiencing sticky-drawing on even Toshiba's mat-finish during the hot months, and that was quite easy to ignore. At the moment, however, glass is a beautiful solution. --Of course, glass is more delicate than plastic, so I'd be cautious taking it on the road, but there's a reason the iPhones use glass rather than plastic. It's just so nice!

    Anyway. . .

    The real exercise with this M4 was to try out an air-cooling system using a Fish Tank air pump. --So I went out and picked up a http://www.thereeftank.com/compare-air-pumps/aqua-clear-vibrator-pump-model-30/ Hagen 30 air pump, and I am sorry to report that I was very disappointed with it. When the manufacturers and reviewers say, "Silent" I think what they meant to say was, "Loud as hell". --Granted, I wasn't able to find one of the French made Rena air pumps at any of the local pet shops, and I didn't want wait for a mail-order item. The Rena pumps are by far the most highly lauded for their low noise factor, but these Hagen ones didn't appear in the reviews to be much worse, so I picked one of those up. To be fair, it isn't super-loud; I've had Tower PCs which were noisier, but after experiencing a nice and quiet M200, I wasn't willing to settle.

    But having come this far, I rigged it all up in order to try it out anyway. I had a length of air hose and I pulled apart the M4 to install it. --I removed the GPU fan and pulled out the spring-loaded stylus garage to make space for the hose to enter the machine. With a fair bit of tweaking and some bits of wire in the right places, I was able to send a nice jet of air through the GPU heat sink.

    The air flow was a little weak. If I wanted pursue this solution, I'd get the largest air pump available, but even so, despite the noise, it all seemed to work. The GPU stayed cool.

    But the noise of the air pump was too annoying, so I figured I'd try the hard-wiring of the GPU fan solution others fighting the M4 heat issue have recommended. So I clipped the gray control wire on the fan and ran the hot and ground wires to the power leads on the most convenient USB port and sure enough, the fan goes round and round. And sounds rather like a hair dryer.

    I brushed up on my highschool electronics know-how and pulled some 10 Ohm resistors out of an old modem card, --which was a lucky find! In this day and age of surface mount electronics, you can't even go to Radio Shack for basic resistors anymore. Apparently, the humble electronics hobbyist is a creature of the past. But I was lucky and was able to cannibalize the parts I needed. --Apparently, 10 Ohm resistors are a standard feature on many old modem cards. I have three such cards, and all of them had these resistors. Cool.

    Anyway. . . I found that three of these resistors in series, (30 Ohms altogether), wound the fan down to a nice level of blow and a much more acceptable noise level. --Still not as quiet as my M200 at rest, but good enough. So I put aside the air pump and admitted defeat on that solution. If the air pumps were as quiet as the ad copy claimed, then it would have been a viable solution, but they aren't. I guess Fish Tank enthusiasts just have a higher tolerance for noise.

    Now here's where it gets interesting. . .

    While doing all of this mucking about, I discovered two things. . .

    1. The interior architecture of the Tecra M4 is NOT conducive at all to decent air-flow. It's awful, actually. There's barely any clearance at all on the underside of the tablet for air to enter the system, and the inside component layout made me feel claustrophobic just looking at it.

    2. Curiously, I discovered that the GPU never actually got very warm at all -even without the fan or air hose to assist in cooling. Under a standard Photoshop load, the thing barely got warm. The CPU, by contrast, got roasty hot, but not the GPU. How odd.


    --Then it struck me; I don't play games. Perhaps users who experience graphics trouble might have been playing those 3D shooter games, or were doing a lot of other very demanding graphics tasks which require the GPU to max out. That, combined with the "Fan never engages" design flaw in the Tecra M4 and the lousy air flow architecture, might cause systems to burn out. Perhaps playing a movie would do the same, but I haven't tested for that. What I can say for certain is that under a basic Photoshop load, (keeping in mind that I work primarily in Black & White), the silly thing barely warmed up at all.

    Hmm.

    But I wanted to fix the air-flow thing. So I pulled the DVD/CD drive and retired it to a box. I also cut out some redundant plastic from the guts in a few key spots to create a nice channel for air flow, and I put the whole thing back together. I also installed the advanced Toshiba power-saver driver for the Tecra as well as Notebook Hardware Control, which in conjunction allow me to instruct when and how much juice flows through the CPU so that it isn't needlessly generating heat all the time. The result is a Tecra M4 which doesn't really heat up more than my Portege M200. (The CPU fan and heat control system works fine, so it never heats up beyond the design parameters anyway.)

    So as long as I stay away from heavy GPU-taxing processes like 3d games, (which isn't a problem for me, since I pretty much lost all interest in such things years ago), I don't anticipate any problems with heat.

    --So that's where I am now. I am considering one other added tweak; I want to install a small on/off switch so that when I walk away from the computer, I can switch off the GPU fan altogether. I often leave my computers on forever and I really appreciate a silent computer.

    Also, I'm about two-thirds of the way through building another desk skirt for the M4 like the one I am currently using for the Portege M200. (See previous links to those pictures.) When I get back home, after being away during the holidays, I'll post some pictures of all this stuff so others can see what I've done and perhaps use some of this tinker-research for their own fixes. I'll show where I cut plastic and soldered wires and resistors and show how to install your own glass and such.

    Until then. . ,

    I wish you all a very happy holidays!
     
  8. thatcomicsguy

    thatcomicsguy Scribbler - Standard Member Senior Member

    Messages:
    2,024
    Likes Received:
    1,064
    Trophy Points:
    181
    Okay. All done.

    I now have a nearly silent and very cool-running Tecra M4.

    That only took a ton of noodling and mucking about. Luckily, I'm a tinkerer by heart, so it was all in fun, but the upshot is that I now have one of the sweetest drawing tablets this side of Cintiq. It took quite a while to do because I'm a workin' man and I was only able to play in my off hours, but now that I've worked out the whole situation, I hope this will be of use to somebody else out there. --And frankly, given that even today there are almost no high-resolution, large screen tablets on the horizon, the Tecra M4 stands as one of the very few viable alternatives to the Wacom wonders. If you're on a budget, then these following discoveries and their solutions may serve you well. . .

    Let's get started. . .


    1. Problem: The Tecra M4's dedicated GPU cooling system is faulty by design. Toshiba installed a tidy little fan, and even positioned it so that it cools not just the GPU but a toasty little IC sitting next door. But amazingly, they failed to hook it up! The BIOS doesn't see it or the thermostat located on the GPU. As a result, the GPU heats up, burns out and thus hundreds of Tecra M4's fail with typical screen issues.

    Solution: Hard-wire it to a local power source on the board. This is a solution which has been described elsewhere and exploited well. Essentially, you run a wire to the +5 volt pin on a nearby USB port. This requires only a steady hand and a soldering iron. You just cut the gray wire and tie it out of the way. The black wire, (Ground), you run to another ground point on the board or simply leave attached to the plug which will (presumably?) have that pin grounded. The red is lengthened with some spare wire and then attached to the alternative power source. Problem solved. Sort of.

    The fan runs at full power at 5 Volts, and I found this full blast rather noisy, so I experimented and found that 30 Ohms of resistance between the USB power and the fan solved things nicely. It runs at about 1/3rd the top speed and is very quiet while still providing enough air flow to keep everything within an acceptable heat tolerance. (I checked this by running the machine through some heavy paces and then opening it up to feel the chip. It was on the hot-ish side, but well below problem temperatures.)

    2. Problem: The Main CPU Fan sounds like a hair dryer! The Tecra M4 is a very loud computer, and perhaps for some of the higher-performance CPUs it can be installed with, it may need to be. But mine tops out at 1725 Mhz, so it really doesn't require such an enthusiastic fan. Interestingly, I found that with the GPU fan running properly half-way across the motherboard, the CPU doesn't actually get that warm; the little GPU fan, while cooling its parent chip, also happens to be directing a channel of air right at the CPU. With this arrangement, the system almost doesn't even need the primary fan. Almost.

    But it does need some air. The problem is that even using such software tools as Notebook Hardware Control and SpeedFan, it was impossible to prevent the BIOS from cranking up the main fan all the way and leaving it on forever for no good reason. I did a lot of tinkering trying to calm it down.

    Solution: Hardware again. Chop the red wire to the main fan and hard-wire it to the same USB +5 Volt power source used last time.

    I put 40 Ohms of resistance on that line to keep the main fan running at a bare hush.

    [​IMG]

    Above is a fairly terrible picture I took a couple of weeks ago before everything was finished properly. I don't feel like pulling my desktop apart again to take better pictures at the moment, but this should give a general idea of what I did. This is a shot of the bottom with the machine sitting on its lid. If you're going to open a Tecra M4 up yourself, then after having removed all the screws, the base should just lift off without resistance. If it doesn't, then it means you missed a screw! (Hint: There's one you can't see unless you take out the DVD/CD drive, and there are also a couple which hide under the lid for the hard drive bay.)

    Having put in resistors and reassembling my Tecra this morning, I've been running it all day, and the CPU temperature is hovering at a chilly 43 Celcius. --And that's on the heat-master of all Tablet PC's, the Toshiba TECRA M4!! What a difference a little tinkering makes!

    Though, I should also note that I used Notebook Hardware Control to reduce the voltage to the CPU. At the highest multiplication, (x 13) for my 1725 Mhz Pentium M, I found I was able to knock the native voltage down from 1.308 Volts to 1.100 with no problems. This cuts the production of heat by a touch. --But for testing it today, I had it locked at high performance, so it never drops below its top speed.

    I also made a couple of small alterations which I'm not sure are entirely necessary, but I did them early on in this whole process, so they're worth mentioning. . .

    I removed the DVD/CD drive from its bay and I don't plan to put it back unless I really need it for some reason. I also chopped out a few bits of plastic which were mounted to the mother board; there's a clear-plastic 'bridge' which runs down the width of the board and it carries some heavy-gauge wires. That plastic bridge effectively seals off half the mother board from any sort of natural airflow. So I just carved out a couple of superfluous chunks from under this thing in order to create as direct and open an air channel as possible to feed the fans. There's not a lot of clearance under the computer chassis for the air intake to do its job, so I wanted to address this somehow. Ditching the DVD/CD unit and carving some air channels was my solution.

    The other thing I did was that I added a little switch to the GPU fan, so that when I walk away from the computer leaving it on but with the screen dark, I can turn the fan off altogether. Again, not really necessary, but I'm happy with it. I ran it to the exterior on a length of spare wire through the stylus garage, which like the wireless modem, I won't be using either since the Tecra is pretty much now mounted to my drafting board.

    And finally. . .

    I mentioned in an earlier post that I'd replaced the screen covering with a sheet of proper glass. And I have to report that I LOVE glass! I thought it might cause issues, but it's a glorious surface to work on. It's bright and smooth as silk, easy to install and costs next to nothing. I highly recommend that anybody dealing with a faulty or damaged screen cover investigate replacing their screen with glass.

    [​IMG]

    Here's a shot to show how the glass fits into place. You can't quite see it here, but the edges have been ground down with a bit of emery cloth. With about a minute of work, the edges were rounded to a smooth finish. Also, because this replacement glass doesn't have any of the printed-on black edging which the original (and in my case, warped and useless) screen cover had, you can see the silver mounting points of the screen below. I rather like this look, but it may not be to every taste.

    So that's it.

    Now, since we're dealing with a dinosaur of a computer, I can't imagine that there will be very many people out there who are really going to care much about any of the preceding stuff. But if you are interested in doing your own hardware hack on an M4, please let me know and I'd be happy to post some proper images and some more detailed step-by-step "how-to" instructions, like how to take apart the computer, and where to solder and what to cut and how to find the parts you'll need, etc.

    [​IMG]

    Here's the finished product. It's basically the same as my previous Portege M200 set-up, just with a new wooden skirt. Note the nice-big space for drawing in! It's about two inches wider than the paper stock I used to work on. Now THAT's a work-space I can live with! It has taken a lot of tinkering to get here, but I am happy to say that I'm finally done!

    Now. . , back to REAL work. There's comics to make!

    Cheers all!
     
  9. Fishface

    Fishface Scribbler - Standard Member

    Messages:
    365
    Likes Received:
    0
    Trophy Points:
    31
    Holy crap, you're amazing. I imagine the rest of your room looks like this:
    [​IMG]
    Yeah, and it's probably bigger on the inside, too.
     
  10. DRTigerlilly

    DRTigerlilly Tablet Lead Mod (Retired) Super Moderator

    Messages:
    6,575
    Likes Received:
    108
    Trophy Points:
    231
    Fishface took the words out of my mouth, you are amazing!
     

Share This Page