My Kindle 3 screen has gone black

I have Kindle 3 keyboard. My initial problem was frozen white screen. I thought it might be dead battery problem and installed a new one. The problem still persists. Only once the screen blinked, light turned green and the booting splash screen appeared. Then it froze. Now screen is off, black. If I insert the charger, the orange light comes up for around 10secs and goes off. I tried all tricks but now it is responding. Please suggest ideas. This Kindle was a gift from a dear friend and I want to revive it.

Edit: I opened the unit and was fiddling around and felt that there is loose contact of either the power switch or the charging port. If I held it in one position, it continued charging and also booted successfully. I have given the unit to a local repair technician. I hope he fixes it. I will update with outcome.

Edit: I am still hanging on with hope for my 8 year old Kindle 3.

I took it to multiple technicians but to no avail. One said USB port is gone and is unable to find a replacement. Another was not too willing to fix.

Latest observation: if I blow air hard into the USB port, (if the device is charged), then suddenly the device starts booting!! Then green light turns on in the power switch and it will be On for a while and normal actions are fine. Again the device switches off.

This blow job solution is very unique and I can't figure out the solution!