As you can see from the first image the battery specs are: 7.2V, 20mAh, Ni-MH, 6/V20HR.

In the second image you see some nasty battery leakage and now we know that there are 6 x Varta V20HR (1.2V/20mAh each) in there, “paddles” for the cable and a metal strips in between for connection, on top and in between (barely visible in between the batteries in the picture). Furthermore the paddles and the metal strips are “punched” into the batteries (there’s probably some fancy technical term for that).

A bit of googling turned up a lot of results, the battery in question is common and cheap, the only problem being the remounting and punching/securing of electrical current to all the batteries.

I’ll leave y’all with this information for now as I personally don’t really crave a correct time and date on the l400… if you decide to make your own battery pack (and succeed) don’t forget to leave a comment!

What does it mean? The L400 can behave as it was supposed to: turn on the fan when it’s hot and turn off the fan when it’s cool enough. No more constant running, horrible horrible fan noise! Also the temperature sensor gives more or less proper readings to for example Speedfan ; temperature (at 700MHz) varies around 48-55 deg. C, around 40-45 at 500MHz.

To check your BIOS version: start the computer and press F2 to enter bios where it shows the version.

To downgrade: download L400A06.exe from Dell’s FTP: Run it and follow the instructions to create a floppy disk and reboot the L400 with it inserted. Follow instructions. After it says it’s complete and leaves you in A:, type l400-a06 /forcemode. It shows a progress window and after a while it reboots and the bios is now downgraded to version A06. Remove the floppy otherwise it will just boot from it again.

Up or downgrading the the BIOS is done at your own risk! Always use AC power (not just battery) when up or downgrading the bios.

The effects of these restored functions on the choice of fan remains to be determined. The 40mm I mounted in an earlier post is a 2-wire fan while the stock is a 3-wire with pwm (speed control).

Edit: The downgraded L400 can start and stop the fan as it should even when using a 2-wire fan. Yay! For those on the lookout for a 3-wire replacement fan I came close to buying a Revoltec airguard 40mm (40x40x10). It should be fairly easy to modify to fit in the L400. The 2-wire fan I use is a Revoltec, part of a chipset-cooling kit.

Edit 2:  March ’09 … Just thought I’d say that the only reason I haven’t posted for quite a while is that with the BIOS finally working (A06)  and a silent fan installed – the L400 is humming along as it should.  Doesn’t really make for an exciting new post if you know what I mean . Anyway, I hope you’ll find something useful here, cheers!

( I’ll add that I got the idea after reading Bay Wolf’s Inspiron & Latitude BIOS FAQ . Although the /nvram switch doesn’t work for the L400 it pointed me in the right (and pretty obvious) direction. )

Sadly, it doesn’t make any difference as the problems remain (acpi stuck at 50deg c, no fan control). As a downgrade from A09 to A03 didn’t work (“PhoenixPhlash Error  New DMI string is too large  Press any key to reboot”) perhaps stepping down through the bios versions can yield one that restores proper functioning.

I’ll hopefully find the time to do this over the coming weeks. Happy fun times ahead!…

Take care if you’re messing with the bios, it’s done at your own risk. Always use the ac-adapter. The Dell FTP is full of different versions of bioses, it also seems they’ve a bunch of L400-files named differently but I assume they should be one and the same. We’ll see…

Can I improve the CPU cooling?
It is possible to fit a 40mm fan into the case, which would make less noise and perhaps move more air. However: DO NOT REMOVE THE STOCK CPU COOLING SINK, unless it’s somehow completely broken of course. In most systems poor cooling is the unfortunate standard and at best the cooling will be as poor as before a “remove and reseat” but perhaps even worse due to loosened surface connections etc.

What causes random shut downs?
A common problem on the L400. The cooling is just not good enough. Due to the small space it’s also close to impossible to fit anything else in there instead of the stock cooling. If you are experiencing sudden shut downs you are most likely suffering from overheating. What you can do is set the processor to work on a lower setting (500Mhz instead of 700MHz) in the bios. On this setting you can even use the L400 without a fan, although it is not recommended in the long run. XP runs quite happily on this lower cpu speed.

The fan is so noisy, what can I do?
Stock fan sounds horrible? That’s also standard… I went so far as to buy a new fan directly from Dell but this only changed the pitch of the whine/noise and left me stranded with the same problem. I advise against buying a replacement fan from Dell for this reason. If your computer is still under warranty you can of course let Dell try and replace it since you won’t pay anything for it. If your warranty has run out you have two options: 1. Leave it alone and try to ignore the noise. 2. Replace or remove the fan yourself and hope for the best. (3. Sell the computer to some hobby modder with nothing better to do…)

Does Linux work on it?
There are a few Linux distributions that work right away, for example Damn Small Linux or Puppy Linux. One potential issue that could cause you to not be able to install Linux at all is that the cd drive that comes with the L400 seems to be a bit rare and sometimes may require custom boot options to start your Linux installation. See this post for more info or this link for examples using Puppy Linux.

And on a more general note:

Is it worth the effort?
The L400 is, in spite of some flaws, definetly a very useful and handy machine. Size and weight are two of the biggest advantages. If you can get your hands on one of these machines for a low price and you’re ready to put some effort into adapting it to your needs you should be more than happy after the tweaking.

What else could theoretically be modified?
If someone had a motherboard specification or just high technical knowledge it should be possible to find ways to power internally placed w-lan, bluetooth etc. This would be a big step forward, but would also require soldering which lessens the number of people that can actually perform these upgrades. Areas of interest: rerouting the 1 internal usb 1.1 port to usb 2 speed (via cardbus somehow?), adding wlan & bluetooth modules (via ide/docking port power?), making universal access to the proprietary ide-port on the back possible.

Edit: Check out this cool mod of a VGA-port to USB-power only (for external cd, fan, cup warmer etc..)

Written on a silent (!), CF-based L400 running an nLited XP SP3. It’s alive!

Anyway, I’ve just completed a replacement of both the system/chassis fan and the psu fan on this machine and it is quite possible although a bit cumbersome. Chassis fan (sucks out warm air from the cpu heatsink/shroud) is quite easily replaced, the only “problem” is you have to keep the motherboard plug since it’s a proprietary Dell connection. Just cut off the cables from the new fan and splice them onto a stump of the old fans wires+connector and you’re done.

I’ve put in 2x Zalman fans, one 92mm chassis fan (ZM-FM2) and one 80mm PSU fan (ZM-FM1). Shouldn’t set you back more than 12$ for both.

The ZM-FM2 runs at 2825rpm when installed as is = untolerably high noise, think hairdryer. You really need to use the resistor that comes with the fan. In the pic you’ll se I made a new incision for the resistor but now that you know you’ll need it you can just include it when you make the first cut. Trial and error my friends… With resistor the fan runs at ca. 1700rpm with greatly reduced noise. No errors reported.

PSU fan does not give any speed reading (I don’t think it did before switching either) but should run at maximum to keep the psu happy, the ZM-FM1 is rated at 0.17A, 3000 rpm while the original fan is 0.41A, 3600rpm (this manufacturers documentation says 0.26A though). There’s still noise coming from the psu that I had hoped to get rid of, a sort of electrical whine / buzz. Well, atleast the overall noise is reduced and the computer seems happy enough. No errors reported.

PSU side views (Cover removed)

Old PSU fan (right) and new PSU fan (left)

New chassis fan after the cable mod

* When to NOT use compactflash as storage
CF cards will wear out fast if you use regular XP/W2K (or any other big operating system) and use the computer regularly. In my case this laptop gets a maximum of say a few weeks worth of real usage per year when I get a chance to go on some vacation and need to study at the same time. The basic rule is; if you use the computer regularly – you need a regular hdd.

* nLited XP
With this said about regular XP – If you’re ready to customize an XP installation I’ve found that nLite does everything I need and simply works right away, and oh – it’s free!. Remove unwanted bits and keep the bobs you want… sure my event log isn’t the prettiest after XP was shrunk to a 180mb large iso but it does work in every aspect I’ve tried so far.

* MLC vs SLC flash
As SLC flash cards have longer life and faster speeds and now can be bought for roughly the same cost as MLC cards, which type to use is no longer an issue. After first ordering a cheap Transcend 4Gb card which turned out to be MLC I quickly ordered another card, this time the Kingston Elite Pro 4GB (SLC) card. Check out Kingstons website for a quick explanation of the difference between the two types of flash cards and which of their models that use them.

* L400 specific notes
I experienced an unexpected shutdown on the first attempt, the heatsink was very hot and that made me realize the bios was set to force the cpu to 700MHz. Apparently not recommended when you’ve messed with parts the way I have. No problem for me anyway, I used it at 450MHz all the time before modding and don’t mind doing so in the future too. Anyway, here’s a good tip for everyone with an L400: If you’ve never removed the factory installed cooling solution (heatsink) – don’t do it now either. You will not be getting any discernable benefits and you may even make the overheating problem worse.

Whoa, the EMI affecting the speaker is even worse than with the old HDD, I have no choice but to remove it or I’ll go crazy. Done and dusted, what an improvement. Operation is now almost completely silent, sure some of it is due to the fan not running but let’s not get picky…

* Perceived speed
Setup of XP slow (nLited XPSP3 at ca 180mb), took just over one hour (on Kingston ElitePro CF 133x 4GB).
From power on to ctrl-alt-del 35s. Normal/fast.
General usage: Normal to fast.
Updated verdict: Normal. (Compared to a 5200 rpm hdd)

Verdict: Feels good and fast, the question is perhaps how long it will last but by putting tempfiles on the secondary MLC card and doing as much business as possible on usb sticks time can only tell. Also changed paging and tempfile settings: Page file none. All tempdirectories rerouted to D:\TEMP etc. All program installations will be made to D aswell, all to help the primary card last longer.

More testing will follow, hopefully it will still work in october when I need it while I travel…

Edit:

* To prevent crashes: turn off power management
After experiencing a few strange crashes when returning to the L400 after not using it for a while, I disabled all power management within windows (control panel – power options – choose always on) and haven’t seen another crash. The screen would show seemingly random colours, blocks, lines and whatnot, sometimes changing in response to keystrokes but mostly just humming along in it’s own universe. First I feared the cf cards had already been used up but since disabling power management everything is back to normal.

Considering how much noise the Dell cd makes and portability issues you’re not going to want to use a LiveCD as a permanent scenario, these tests are meant as test whether a certain Linux distribution indeed works and is suited for a permanent installation on hdd/cf/etc.

Knoppix 5.01 LiveCD
Confirmed basic functionality, once the desktop environment is started it feels quite snappy. No trouble installing, just pop in the cd, boot from it and wait. You can get a permanent environment by saving it to usb, to retrieve it you boot from the cd as usual and then specify you want your saved environment by entering ( xxx ) just before the loading starts. Easy enough. It is possible to make a hdd installation but not recommended as Knoppix is apparently only intended for live CD use.

Puppy Linux 2.15 LiveCD
Confirmed basic functionality. Longer boot than Knoppix, but desktop environment feels good. Quite memory hungry for what is supposed to be a distro for old, slow computers. The L400 being maxed out at 256mb leaves you with very little space to move around in the Puppy desktop (ca 10mb free). LiveCD therefore not recommended, if you want to run puppy, make it a permanent install. Could not install a .deb package, pupzip suggested to install “undeb” but I could not find any such file with the application installer.

Puppy Linux 4 LiveCD
I’m trying the new version aswell, I like Puppy for some reason. No luck here though, just after starting to boot it says “pup_400.sfs not found. Dropping out to initial-ramdisk console…”. FAIL. SOLVED! Thanks to this thread, just entering “puppy ide=nodma” when asked to wait for normal boot or specify boot options makes puppy very happy. This is apparently something that can happen with certain cd readers, in this case the one that accompanies the L400. Version 4 feels fast and fresh, now leaving ca. 110mb for operations (of 256). Confirmed basic functionality.

Ubuntu 8.04.1 Desktop LiveCD
First burned cd would not complete install or cd test, just “Error reading boot cd”. Only option is to reboot. Helpful not so much. A third burn got it working but sloooooowwwwly loading. Seriously slow, let it work for 10mins and then shut it off, any potential result would have been excrutiatingly slow or non-responsive. Silent loading (just a bar going back and forth) looks good but the user has no idea what’s happening, or in this case what’s not happening.

Xubuntu 8.04.1 LiveCD
A slimmer Ubuntu should work I thought and popped this one in, first loading went much quicker than the regular Ubuntu. Then comes the silent loading part, a little bar going back and forth while it sometimes acesses the cd and other times just sits there. After ca. 4 minutes the bar turned in to a progress bar and got to 100%, yay I thought, here we go! But then the computer just shut down instead (not overheated). FAIL.

Fedora 9 Live KDE LiveCD
First burned cd will not complete install, outputs “over current change” and a bunch of buffer errors on device sr0? Not very helpful. Just tell the user what the problem is in english? Documentation seems outdated, see this . None of these files exists on the server and you have to browse the ftp server manually to find out. Main page confusing with all the different versions and no intuitive explanation of what’s what. Calls all relevant files i686 while documentation says to get the i386 files. i386 files exist on the server but holds no iso files? FAIL.

Damn small linux 4.4.5 LiveCD
Some usb erros at boot. Not a problem it seems since it started just fine anyway. Feels basic but nice, got the media player to work almost right away (had to save the .pls and open it to get a stream working). Cannot install FirstClass (the .deb package I’ve talked about) even after I managed to follow instructions to “Upgrade to GNU utils” and “Enable Apt” which seemed necessary. When running the dpkg (depackage?) command specified at firstclass’s website it just says that the .deb is not a debian format archive. Some quick googling yields no solution. OS feels nice and fast though, if I could install what I needed this would probably be the Linux variety I’d use, after sprucing it up a little.

Debian Live Lenny KDE Desktop LiveCD
Disk error. Boot failed. Nuff said.

Winner: Damn Small Linux! Small, fast and best of all: actually works.
Second place: Puppy Linux. Has a nice feeling about it, pretty fast and works.
Last place: Fedora 9. Confusing website, non-functioning installation. Way to not go.

I have to say that -in my view- using Linux on the L400 is going to have to take some work and is sadly not something I can just install and live happily with ever after. For my part it means I’ll return to my original plan, to use XP (or an nLited version of it) or perhaps nLited Win2K on this machine.

Edit: As you can see in the comments below, one peson reports success in installing Debian and Ubuntu. The post reflects my personal, linux-noob thoughts and are not to be read as final verdicts on a whole OS. Some of them I couldn’t get to work but there are obviously people out there that do. Good luck

If there’s anyone out there with a Dell L400 using bios version A08 or lower (especially A03) – please report:
A. Does the fan start at boot and then never start again? (True for BIOS ver A09)
B. Does the fan start at boot and then start again during use, i.e cycle on and off depending on what you do?
(This is how the fan should normally work.)
C. What temperatures and/or fan speeds does Speedfan report? (In BIOS A09 it falsely says no fan and ACPI temp 50C)

Edit 25th Nov ’08:
Succeeded in downgrading to version A08, see more recent post above.

Confirmed because the behaviour of the fan I’ve put in is just as good/bad as with the original, even though this fan lacks the yellow cable = rpm readings and whatnot. This is good in the sense that it doesn’t run the fan a lot, bad in that it may overheat and shut down or run the fan constantly making the user shut down instead… I wouldn’t do any critical work on the L400 and whatever work you do do needs to be backed up frequently.

It is rumoured that the A03 bios may restore some or all functionality and I will be testing this within a week… stay tuned Earlier Dell bioses avaible from their FTP here.

In other news; the Addonics adapter has arrived and is confirmed to be working (New 2gb 80x card works, old 512 and 256mb cards refuse to work properly), now I’m just waiting for a bigger and better 4Gb 133x Transcend cf-card to arrive.

Fits? A snug fit, not secured but ok. Thanks to the small spaces it’s more or less forced to sit where it is and shouldn’t be able to move around too much. Added a patch of double sided tape underneath, not sure how much contact there actually is between it and the case/felt-pad originally installed. A slight bulge in the upper left corner of the keyboard could not be avoided. Edit: The fan measures 40x40x10 (original size)

Noise? Well, the fanleaves themselves make no discernable noise, there is some kind of little *krrx* coming from what may be miniscule dust (from the filing) stuck in the motor. If I had to do it over again I would enlist someones help and have them vacuum the filings away from the fan as the operation was performed. If the keyboard is screwed down all the way with the leftmost screw the fan starts hitting something. Leaving it slightly unscrewed shouldn’t be an issue.

Fan control? Sketchy as it ever was. Starts when the machine boots and then shuts down, like before. Stressed the 500MHz setting for 30 minutes but could not get fan to start, like before. Restarted and set it att 700MHz = fan runs constantly, as it did before if the system was hot when rebooted. With the new fan that’s not an issue! Testing will continue…

All in all a more or less sucessful mod I’m proud to say

Oh, and a useful tip to anyone about to adapt two wires into a three-pin connector: Leave a portion of the old cables sitting in the connector! I cut it off right by the white connector and that just makes it irritatingly difficult to stuff new cables in there and securing them with tape. Duh! Just leave some and intwine the red and black cables from old and new and put a little electrically insulating tape around it and it will look neat and professional. If my fan solution works in the long run I’ll sacrifice the second dell fan to get a decent looking connection.