1) The hard plastic bezel is glued to the softer plastic surround.  What you'll want to do is use a sharp knife to slice through the glue and pull the soft plastic away.  The glue isn't perfect - you may be able to pull parts of the softer part away without having to cut the glue.  Start with an area where the soft plastic can already be pulled away.  if you do it carefully, you can separate the two parts without tearing the soft plastic.  I've done it successfully dozens of times.

At that point you can remove the front section, and gain access to the screws for the back section.

2) Here are the schematics for the chumby Classic V3.7.  I think the power circuitry in 3.8 devices is similar.

http://files.chumby.com/hdwedocs/hardware_v3_7.pdf

CC devices generally feel like they're running hotter than C1 - the heat from the wifi dongle is dissipated through the screen on the CC (can't remove the heat through the stuffing and leather), instead of convection in the C1.  The actual heat is about the same.

Duane, thanks for sending the schematics and giving me the teardown info so quickly!

(diamaunt, thanks for the info you provided, also.)

- - - - - - - - - - UPDATE - - - - - - - - - -
Upon comparing my actual motherboard to the CAD drawings you provided, my board appears to be somewhat different. 

• If you look at P.9 of the docs you provided, that board has one tab (4.0mm x 4.17mm) that protrudes out from the right side of the board.  My board has two such tabs at that end.

• P.9 also shows a 20-pin connector (for ribbon cable?) in the lower right corner of the board.  My board has no connector in that location. 

• However, my board has a 26-pin connector (for the ribbon cable) at the opposite end of the board (the end at the left side of P.9).  No such connector is shown on your drawings.

So I think my board does not correspond to your drawings.

- - - - - - - - - - END OF UPDATE - - - - - - - - - -

The schematics do not clearly indicate the physical location of the various components ... i.e. whether a given part is on the motherboard or on the rear board (with the connectors).

When I first got it apart and looked at the construction, I was hoping that the power circuitry was located on the rear board, which would be easier to access.  However I find at least some of the regulators (U300, U301...) on the motherboard.

If "chumbilical" actually refers to the ribbon cable, then it appears that the protection circuitry is also on the motherboard.  (I don't seem to find a schematic of that small rear board.)

I was hoping that perhaps the fuse in the RAW PWR circuit had opened (or a diode or choke had gone open).  So I tried to power the device using a fresh 9V battery in the battery clip.  Upon pushing the power button, still nothing.  So, unfortunately, I don't think the problem is in the protection circuitry.

Interestingly, if I connect 9V to the battery clip (through a DMM) I see 0.18 A of current.  I see that reading as soon as I connect the battery, and it does not change if I push the CC's power button.

At a quick glance over all the schematics, it appears DC IN PROTECTED goes only to the +5v regulator.  However the schematic says "BATTERY signal goes to TS/codec chip..."  so that 180mA could be going one of two places.

To narrow it down, I applied the same 9V battery to the rear panel coaxial power connector.  Again I see 180mA.  So I think that rules out the TS/codec chip. 

My conclusion is that both sides of the protection circuitry are OK, the DC is getting to the +5v regulator and to a few other places, as shown on the various pages of schematics. 

And something, somewhere, is drawing 180mA.  Would a CC normally draw that much in "resting" state, with no backlight, no display, no audio?

To do any further analysis, I'd have to start disassembling boards at the very least.  However, I don't have a stereo microscope and micro soldering tools that I'd need to work on these boards.  So I'm not sure there is any practical benefit in my going any further.

I'd appreciate your feedback on what I've done up to this point, and any other suggestions you might care to make.

Thanks again for your help!

Thanks, Duane.

I definitely have a 3.8, because it has slider controls for day and night screen brightness.

That being given, is any of the power circuitry for the 3.8 on the rear connector board? Or is it still on the motherboard like the 3.7?

Do you have a set of docs for the 3.8?  Or did those vanish with the demise of Chumby Inc.?

I'm pretty sure the failure was caused by an overvoltage power adapter.  Is there any "normal" failure mode of the internal PS components?  Is it realistic to hope this can be restored?

(I'm torn here.  Based on a few days of listening, I thought the sound from the CC speakers was a lot nicer than the sound from the C1.  But with my background in commercial & broadcast gear, I have to admit that the "works in a bag" concept of the CC doesn't thrill me.)

Thanks again!

I always used my C1s with external amplified speakers.  But that takes up a lot of counter space and is of course non-portable.  The CC wasn't hi-fi, but it was a lot more bearable than that C1s.  I could stand listening to it bareback for a few hours.

It's too bad Chumby never made a truly portable unit, the size of a portable radio or small boombox, with two decent speakers and room for a battery that would provide a few hours of playing time.  Personally, I would find that form factor much more practical than a soft amorphous lump.

This has probably been asked and answered, but I've never read it.  What was the original history behind the lumpy leather concept?

This device seems a bit like what you're looking for.

I posted them as an April Fool's joke a couple of years back, however, they're real working prototype devices we just didn't take into production.

I am still trying to put my order in for one of those C3s. There must be a very long waiting list.

Right - the 3.7 *hardware* supports "full on", "dim" and "off".  The Control Panel screen for brightness exposes this as the two buttons and the "off" button appearing on the Night Mode screen.

The 3.8 hardware supports variable level brightness, as well as on/off, displayed as two sliders on the brightness screen (one for normal use, and one for Night Mode) and the same "off" button in Night Mode.