special problem on PIC

[wayne]

i had costracted the own demo doard which using PIC18F4520. the operation of this circuit is the buzzer will triger when one of the shock sensor was detected. this operation has been tested on PICDEM 2 PLUS DEMO BOARD and it run properly. when i constracted this cirucit in project board, it is work well also. but when i move this cirucit to other power plug supply, it cant work properly anymore and when i touch the OCS1 or 7805, it work properly again once i release my hand then it cant function back again. the most funny is that one of my house power plug supply can work very well but everytime i change other plug it has the problem as mention above. why like this???? the shock sensor which i using from cytron and the datasheet or circuit diagram were uploaded at here. everyone who know my problem please give a helping hand. thank million!!!

[yonghui]

all the gnd are properly connected?

[wayne]

thank for reply, i comfirm all are common ground together. i build my circuit in project board, it still havent sodering and will it work after sodering? because i teasted on PICDEM 2 DEMO BOARD it always work fine.

[robosang]

On protoboard/breadboard?

Is super not stable..... many have experienced it.

[wayne]

yes, i build in breadboard. why not stable? i also hear about it and better build in PCB board. but i afraid the problem still there after soldering in PCB board.