Mar 132022
 

The other victims of the Brisbane 2022 flood at my workplace are a pile of Leader SN4PROv3 “NUC” clones, like the ruggedised Intel NUCs, were purchased as cheap “PLC”s. Out of the box, they run Windows 10, which seems insane given they, like the Intel NUCs, only have 4GB RAM and sport dual-core Celerons running at a whopping 1.1GHz. (Wow, let’s see that play Crysis!)

Most of these actually survived pretty well, with all but one booting. I had visually inspected each by opening the case and having a look inside, but obviously on this one specimen, I missed something. So let’s crack it open and have a look.

Leader SN4PROv3

First step is to move the rubber feet out of the way and remove the 4 case screws hiding beneath.

The four case screws hide beneath the rubber feet (which I have moved)

The Leader website claims these machines run eMMC. In all the units I have here, it appears all of them are not eMMC, but rather, are M.2 SATA SSDs. I’d consider that an upgrade. My guess is maybe the first of this model had eMMC, but then the chip shortage bit and so they endowed these ones with SATA. The footprint for the eMMC looks to be just near the battery.

In any case, that SSD is in the way making the screws to the left of it hard to reach, so let’s get it out of the way.

Removing the SSD to access board screws

The SSD here is a “Kston”-brand SSD… Not Kingston, don’t be fooled by the lettering…

The SSD… not pretending to be a “Kingston”, honest!!!

Anyway, having done that, the screws that hold the board down are now more accessible, so let’s get them out.

PCB screws

Finally, to actually get the board out, we’ll need to pop the rear cover out. There are four little plastic catches that we’ll need to push down and out to release the rear panel. A flat-blade screwdriver works for this.

Removing the rear panel

Having done this, you’ll note the board now rattles back and forth. Use the new opening to push the board out of its resting place.

Removing the board, pull it up in the direction shown.

As you do this, you’ll note the case will still interfere, but now at least you should be able to bend the plastic out of the way.

Bending the case to get the connectors past

Now, at this point you’ll note there’s some coax feeds connecting two stick-on antennas to the case. The mainboard end is socketed but the case end are just soldered on with no strain-relief!

The stick-on WiFi/Bluetooth antennas

The heatsink/fan assembly can now be seen, and it too is held on by four screws.

Heatsink/Fan screws

Undo these, and we should be staring at the CPU.

Ohh, so that’s what was causing your POST issue?

We can see the culprit here that caused the failed POST… there’s a tiny 8-pin chip in amongst that rust residue, and of course I’m fresh out of the isopropyl alcohol spray… so we’ll try some circuit board cleaner on this and see if she goes afterwards.

Mar 132022
 

So, following on from the fun and games of migrating a network, the other outcome of the flood is cleaning out hardware that wasn’t so lucky to escape the flood waters. My workplace does a lot of industrial automation and meter integration work, and the tool of choice lately has been Linux machines with NodeRED (this is what WideSky Edge is built on).

Seeing a chip-shortage, they bought up a big stock pile of these ruggedised Intel NUCs. These machines are no front-page news spec-wise (dual-core Intel Celeron, 4GB RAM, 64GB eMMC), but are good enough for the task. However, mother nature had other plans, and machines that were not IPX7 rated got a dunking no one anticipated. Miraculously, I’ve managed to get most of them going. Initially when I got them home was I gave them all a rise in tap water to just wash away any mud and other muck that may have been in the river water, then left them to dry for a few days.

This didn’t help matters, with units still refusing to power on, so I opened each one up and sprayed them with some isopropyl alcohol spray… using an entire 300g can of the stuff on 14 rugged NUCs. I did this to one at first… and found to my amazement, it booted!

She lives!!!

I did find though, there was no documentation on how to disassemble one of these. Intel’s docs don’t even tell you. And much of what I did find was YouTube videos… apparently people are incapable of taking still photos and documenting the process in plain text. Never mind, I figured it out, and will document the procedure here.

I’m not going to bother identifying chips, this isn’t iFixIt. I’m primarily concerned about cleaning off any muck that’s causing the boot failure.

Disassembly

So presumably you’ve got one of these NUCs in front of you.

The NUC8CCHKRN2

First step is to flip it over (front still facing you), and you’ll see 4 very obvious screws. These are captive screws, so no risk of them rattling loose.

The screws for opening the case.

Inside we see the WiFi/Bluetooth module, a space for a M.2 SSD/peripheral, the RTC battery and the top of the main board.

Inside the bottom cover

The first step I found easiest is to remove the screw and nut that holds the WiFi card in place. This is a spacer+screw assembly which does double-duty of holding the WiFi card down, and holding whatever full-length M.2 peripheral you put in there. Pliers work for rotating that nut. Removal will allow us to better get the coax antenna feeds out of the way to access the screw beneath.

The nut+screw assembly holding the WiFi card down

Now we have that out of the way, we can remove the screws that actually hold the inner chassis down. There are two screws, one on each side.

The screws holding the inner chassis frame in place

Now, to finally release the inner frame, there are two catches, one each side of the case.

The plastic catches holding the chassis frame in place

You’ll want to push the plastic outwards whilst pulling upward on the USB / Ethernet connectors. Do one side, pulling the frame out by 5mm, then do the other.

Catches away!

Having done this, you’ll see continuing to pull on these connectors, the whole assembly pulls out. From here, we now can focus on extracting the PCB from the inner chassis frame. The PCB is fixed by two screws which the silkscreen helpfully points out.

The inner chassis removed, two screws fix the PCB itself.

Undo these two screws, then flip the board over, you’ll find 4 more that bolt the heatsink to the CPU.

Heatsink screws

These screws are captive like the case screws in the initial step, so just undo each a few turns, move to the next screw and loosen it, etc, and keep going until the PCB comes loose.

…and we’re in!

The PCB should now come free and you’ll be able to see the CPU and RAM (which are soldered-on).