Taking the espresso machine apart proved slightly challenging. As always, live parts inside, so don't let them get away (or to bite you!). There's a good blow-apart picture set at https://icancompute.wordpress.com/2013/07/18/haushaltshack-krups-dolce-gusto-circolo-pumpe-defekt/ - unfortunately the guys there (In German no less) can't remember or seem to be able to explain just how they got it apart. "Tab manipulation" indeed.

The back plate of the device is held down by six, long screws looking like security hex key 10, or maybe 15. I had a security torx 15 at hand, but it was just slightly too large. Fortunately, the security screws are no match for a flat screwdriver head of requisite width. The two bottom ones open upwards towards the roof of the brewing cavity, so a shorter screwdriver comes handy.

After the screws are off comes the hard part. It's hard to figure what part comes off next. In fact, nothing really seems to come off easy, but pulling the inner shroud of the brewing cavity outwards - with the screws removed, again - firmly enough should allow it dislodge. However, do disconnect the led-light connector on the back first so it doesn't get torn off. The four tabs visible just around the cavity on the back side aren't actually holding them down, they're just for alignment, as well as a fifth one just visible on the top of the cavity. The small holes on the drip-shelf grooves are there just for distraction as well.

There are four tabs holding it in place, however, but those are inaccessible from the outside, so your best bet is to just apply firm but gentle pull on it. Mine came off easiest from the bottom end, and from the shape of it that might be the case in general. Pulling the bottom end out and slightly upwards might be best strategy. After the shroud is off, now is your last opportunity to just wash it and put it back in if you're not qualified for working with mains voltage; the pump and heater inside operate on it and have many exposed terminals.

If you DO decide to carry on, the side panels can come off next. Start with the one opposite to power-button, again starting from the bottom. The attachment mechanism should be self-evident from looking at the bottom of the thing; just lift the plastic ring over the peg until you can slide it off. The side panels are also connected shallow tabs on their edges at the upper and lower ends, but those should offer little resistance.

Getting off the side panels reveals the innards. The electronics are labeled as "APOLLO Mainboard v2.4". Googling up on this turns up quite a few decent images labeled as Krups Nespresso KP5002 as well as a service manual for Krups Cube Nespresso XN5005. Unfortunately none of these look very useful for modders, although I'm keeping them in mind, and will also have to see if there are already mod instructions for those models!

Closely examining the electronics mainboard does reveal some useful things, however. The pump and heat block are ran off the mains power, good choice but awkward for hobbyist modder. There's a clear separation of the mains voltage and low voltage on the backside of the main board, however, so keeping connections clear to the low power side and hands off powered device should help avoid sudden death.

Switching mains power to the heater and pump from the low power side is handled by two MOC3063 opto-couplers with zero-crossing circuit. The hard way to mod this would be to lift off the low-power side legs and connect my own controller, however at present I'm looking whether I can effect a less destructive modding employing the existing circuitry. Taking control of the inputs including what's labeled as a NTC thermistor should do that, although if there's already PID inside, the effect on that will be useless at best.

On the flip-side of the mainboard there's a small SOIC16 that looks to be the brains of the operation, upper row reads F8212 and lower row looks like IO4pm19, with a five pin programming header connected to it. My uneducated guess would be it's an Intel MCS-51 (8051) or clone microcontroller. Finding out all the intricacies to re-program it would be another project altogether, so for now I'm going to mostly skip it.

However, the first order of business will be to get around to determine what kind of NTC or temperature controller is inside there, after that I can decide how to proceed and if I should settle for just temperature logging and automatic brewing with the existing temperature controller. I'm measuring 110k across the NTC at room temperature (23C), but will take a bit until I have time to arrange proper dynamic test.