Pidock 400 Active Cooling 1: LCD Driver Board

A project log for Raspberry Pi 400 Daily Driver

Learning to use a Raspberry Pi 400 laptop as an everyday computer and sharing the results.

DustinDustin 11/25/2021 at 16:252 Comments


Getting the Pidock 400 apart was far easier than I thought it would be. It looked like there was super glue holding the front corners together, but it was just some crappy plastic work. It's held together by clips and quite easy to get into with some sort of prying tool. I used a small flat head screwdriver. The hinge covers are side specific, so just switch them if they leave a gap on the back side. There is a bit of 3M VHB tape that holds down the center bit at the back. This may be tough to remove, so take your time. I was luck in that someone put tape on the bottom AND top but never peeled the backing off the lid side, so it came right apart. I left it like that for easy disassembly. I'd use adhesive double sided Velcro there in the future. I used to use it for RC planes and it was very handy. I don't have a picture of the case open without the fan installed, but there is actually a small grate there with mounting holes for a fan. I have 4 of these fans on hand...Perfection.

Underside of the Pidock 400 deck
Here's the underside of the Pidock deck. Bottom center is the touchpad hardware. It's actually braced under the buttons. Not bad.
Pidock 400 Internals, fan mounted
Here's the inside of the Pidock 400, fan screwed in place with brass wood screws I had laying around.

Fan Installation

Installing the fan was far easier than I thought. There is a place with screw mounts and vent holes that seem to be designed for the exact size fan I had on hand. The holes line up, everything fits, the cables even reach the 5 volt socket on the board. I ended up pulling off the black plastic end on the ground cable of the fan, as the two side by side wouldn't fit into the socket on the LCD driver board. This worked well enough and I used tape to hold the wires down. This worked better than I thought it would.  Not too much to say, so check out the pictures.

Underside of Pidoc 400 LCD driver board
On the underside of the board is a 5 volt power socket. I know it's 5 volts because it's labeled on the top of the board. That label is what made me turn the board over. I was expecting to find solder pads and have to solder the fan wires on.
Top of Pidock 400 LCD driver board, showing the 5 volt and ground labels
Here is the label that go me interested in he underside of he board, where I discovered a 5 vol socket.
Fan wih modified wires in Pidock 400
Here's how I go he fan wires to connect o he socket on he LCD driver board. Used a small pick tool to release he plastic sheath on the wire. I ended up taking it off the ground instead of the positive, as pictured here. It works just fine once taped down.
Fan connected to Pidock 400 LCD driver board.
Here's the fan connected to the driver board, minus the tape that holds it in place. The wires are very loose, so the tape was not optional. A proper plug is what I should use, but tape is what I have.


After verifying the fan runs and the Pi boots and has video, I assembled the case. I ran into some trouble getting the corner over the driver board clipped in, but I suspect it's because the entire case has warped since it has been in use. I know good plastic mold making when I see it, and this is decent, but not great. It looks like proper trash compared to my Hilti hammer drill, but Hilti is known for proper industrial quality, not budget niche electronics. Overall, this thing is great quality for the price. I would personally pay double for better plastic, more ventilation, tons of cooling, an SSD mount and adapter cable, keyboard light above the display, power button on the case, and built in battery and speakers. That would make a proper Pi 400 laptop, which would make me very happy. I might just design that one of these days. If I ever have the time, skill, and energy. Until then, the Pidock 400 will work fine. The rest of the assembly went just fine. I did get the hinge covers on the wrong side, which left a puzzling gap. I immediately suspected they weren't symmetrical as I first thought, and a closer look at the tabs verified they are different lengths. Switching them around had it back together once more. The entire bottom seems to have warped, causing the Pi to sit up a little higher than it should. I may heat the case and gently straighten in back out later, but it's a very minor problem right now. It does not effect the user experience at this time.

Pidock 400 cable management
I hadn't been able to figure out what the two clips the channel where the touchpad USB cable runs are for until now. They hold the USB plug neatly in place when the touchpad is not connected. There was definitely a good deal of thought put into the design of this device. I really appreciate the little details and love my Pidock overall. I think it's a fantastic idea and well executed for the price. The silver disks are magnets that hold the Pi 400 down. There are 4 of them and they do help significantly. I tested to see if they are actually holding the Pi down, and they really are.
Pi 400 slid forward in the Pidock 400
This is how I access the rear IO on the Pi when using this device. I simply slide it forward and tip it towards me. It's actually far more convenient than any other device I have ever used. Even large flash drives and SD card readers can be accessed like this with careful tilting. I let the Pi cool down and run like this when it gets hot as well.

Future Considerations

This little fan may or may not help the system run cooler, but I feel it's well worth investigating. The Pi will not likely benefit from this at all, but time will tell. The left side of he palm rest may feel a little cooler, which would be good enough for me. Anything to help the system last longer. I don't think the power draw from this fan will hurt the board. It has a 5 volt output for a reason. I'm curios as to what it is originally for. I have plans to add a 12 volt 5015 blower fan, normally used for 3D printers. I'll tie this into the 12 volt power jack so it doesn't put extra strain on the LCD driver board. This fan will be to cool the Pi, and I may add a few if needed. There is a fair bit of room inside the Pidock case and I may even have room for the boot SSD inside with the fans. I'll order the fans and if they don't work out in here, I'll find another use for them. I just peeled open the display bezel a bit and found there should be enough room in there to add a keyboard light where a camera would usually go. I never use webcams, so an LED here would be perfect. I think I'd add a red LED as I find red light very pleasing in the dark. I'll add a switch to the Pidock case when I get around to adding the LED. I can pull the power from the 5 volt port the fan is connected to. Now if I could only dim the LCD....

The fan I just installed may be useless, but I at least know what is possible and how to work on this thing. I recommend the Pidock 400 to normal users and hackers alike. It has loads of potential and very well thought out features that make it daily driver friendly and hacker friendly.

I think I may be the only person tinkering with this thing and posting the results online at this moment in time. I can't find any hacks or info on the Pidock 400, which is why I started doing them myself.


Andy Piper wrote 11/30/2021 at 02:45 point

Thank you for writing about what you’re up to! I can’t quite justify a Pidock 400 to myself at the moment, but I’m fascinated by what you’ve been up to.

  Are you sure? yes | no

Dustin wrote 11/30/2021 at 16:10 point

You're quite welcome! I couldn't find anyone else documenting this, so I figured I might as well be the one. I love the Pidock 400. I'm using it at the library right now, actually. I find the antique woodwork, leather chairs, and stone fireplace very cozy. It's nice to be able to use my Pi here without drawing any attention! I ordered a blower fan to cool the Pi itself. Check back next week for that log! Thanks for commenting. I really enjoy talking to other hackers.

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