Hi.
I just got it open using a credit card and carefully but forcefully working it in and around.
The removes the top over and the screen which contains the buttons and has an O-ring around it.set this aside and you can then remove the main screen and PCB from the bottom casing. Carefully prize it up using the small holes. 2 near the bottom buttons and one at the top. Once you remove the screen and PCB be careful as there are small springs which attach the contacts in the black base section to the PCB for battery (+/-), buzzer, and serial connection. That's 5 wee springs in all and they will easily fall out.
The screen can be separated from the PCB easily with 3 small clips. Again be careful as there are 2 metal contacts, 1 for the mode button and one for the bottom buttons which will fall out.
Reassembly should be very simple. As usual you'd want to clean and grease (maybe replace) the orings. There is a big one around the screen, what looks like 2 around the pressure sensor, and one around each button shaft (I think, too small to see but the shafts could be removed by taking the circlip out.
There is no sign of water ingress in mine so I suspect the issue with mine is component failure. I'm going to get some advice from someone more knowledgeable before proceeding but hopefully an SMD capacitor or the crystal is all I need to replace.
Both of the larger ICs on here appear to be purpose build. I took the sticker off the larger one and it says Suunto on it. Again I need to speak to someone who knows more, but with a bit of luck it might have an ARM core with some code for the algorithm in eeprom, meaning eventually we could load it with different algorithms (Although for recreational diving I am a fan of Suuntos RGBM).
One possible fun experiment could be to get the beeper to play nokia phone ring tones during your surface stop, that would be a fun project and really annoy other divers.
I'll upload some photos soon.
