Fix Yinlips YDPG16 Button.
I bought a Yinlips YDPG16, unfortunately the B button had a habit of sticking after being pressed. It needed fixing, with this as an excuse to open it up that's what I did. What warranty?
First though some shots of the mainboard after opening. Click the photos for more detail.
Photo 1: The little piece of circuit board stuck onto the inside of the backshell is the wireless aerial. Also notice the Nub has 6 visible contacts suggesting it is analog not digital. Photo 2 shows the "A10" CPU with RAM to the left and onboard FlashRAM to the right, note the extra solder pads for additional Flash...
With the hardware hacker eye candy out the way, on to the main fix:
Photo 3 & 4: Jammed in B button
As you can see the button is stuck in. Flicking it will sometimes get it to spring back but it looks like either it's poorly fitted or the rubbery pad is a bit too weak to pop it back up in normal use.
Photo 5 & 6: making foam spring washer and fitting it under the B button
I decided to give the button a bit more spring by adding a small piece of foam. I punched a "spring washer" out of some scrap and fitted it over the button so that it ended up squished between the button and rubber pad (The buttons seem to be glued onto the pad). This gives the button a tiny bit more push helping it pop back up.
Diagram 1 & 2: Sticky button & Foam spring washer added
Photo 7: Button fixed!
It was a little tricky putting it back together but I got there.
How to get rid of the Chinese soft keyboard?
The PG16 comes with a stack of Chinese localised cruft, including the keyboard. To make this more annoying most of it can't be removed without root access and the settings menu on my device didn't display "Android default keyboard" as an option until I installed Hacker's Keyboard from market. When setting this up the default (English) keyboard option is now listed in settings, so finally we can get rid of the Chinese keyboard and use either the default or hacker's or any other keyboard.
DIY OTG cable
I made an USB OTG (On the Go) cable from some junk, when connected an old USB mouse "just works". After a bit of testing so does a keyboard and various flash sticks. The tiny black speck in the middle of the screen is a very Linuxy mouse pointer. Cool!
Proceed at your own risk, wiring USB ports up wrong can damage your hardware.
Photo 8: OTG cable testing - Diagram 3: OTG cable wiring