Where to start troubleshooting this camera?

[Azhar]

I bought two brand new but faulty pen camcorders (A.K.A. Spy cam), I was hoping they are easy to fix, but I don't know how and where to start checking! Any ideas what the fault could be?
When I plug the devices into the PC it doesn't show "new hardware" but the the device start charging (both LEDs turn on) and after I unplug the LED remain on for a while till the battery get drained!
Is there any hope fixing them or there is no hope?
Any advice appreciated!

Please check the photo

[ablacon64]

A while ago I got a mini bluetooth device with that same sympton, changing the battery solved the problem. Anyway, I would start by cleaning them with IPA or acetone (maybe use an ultrasonic cleaner for that, but remove battery first) and drying.

[Psi]

Most of the time when you get dead china stuff in the mail, its due to crap china leadfree soldering and the vibrations from transport breaking the tiny amount of solder that was just hanging on.

You may find the device is detected if you press down on some component or pin.

Inspect every solder joint closely and re-solder any that look dodgy. Especially any soldering around the usb port / usb chips.
Also look for solder bridges but be careful you don't damage things trying to clear a bridge that's actually joined together by a track.

[brainwash]

Check all connectors (start with usb data pins), then solder bridges, then unsoldered pins.

I bought two months ago a big box full of DOA gadgets for ~20E. Spent a few hours putting stuff back together and now it's worth ~400E.

[G7PSK]

Try powering it from a separate power supply like another battery or a bench power supply.
Sometimes the equipment is not detected until the battery is charged, I have a Sony Ereader that is like this. When I first got and pluged it in it was not detected so i took it back, all they did was charge it from a separate source and when I got home and plugged it in lo and behold there it was on the computer, since then I have noticed that if the battery goes to low it is not registered by the computer until the battery reaches a certain level now it is getting older that is more frequent. 

[Azhar]

The battery get charged when I plug it in, and the LED indicators remain on and can not be switched off after awhile the battery dies

[peter.mitchell]

check continuity of the tact switch, if it is stuck closed or low resistance it may cause odd issues.

[Azhar]

Thanks to you all