My V200 is dead

[elkirf]

my samsung V200 cell phone dropped on the floor and wont power on again. i took it a a repair centre and the phone worked for 2 weeks. One thing i noticed when i watch the engineer work on my phone is that he packed one of the processor and the in-built battery with plastic (just above the SIm connector). when i returned the phone to him the phone will power on at one time the next moment the power-on botton will not function again. At one time the cell wont power on but when he keeps fidling with the charger inserted into the charging port and removing it, the phone will suddenly power on without him pressing the power-on botton.
Pls i will like someone to tell me what can be done to the phone so that the power botton will function normally.

my e-mail is [email protected]