aaron_do wrote on Mar 12th, 2014, 1:58am:Hi neuro11,
yeah you're probably right. If the diodes had failed then I don't think it would matter which source you're using. Somehow your circuit is loading down the source, but I'm not sure why...if you use an multimeter to check the resistance between the input and ground, and input + to -, I assume you will get a high impedance?
yeah...I get high impedance.....
I had another board (same unsoldered) and I just soldered input pin, connected them to the source. then measured the voltage in resistance pin(of the input) vs different GND point of the circuit. Its ok. Then I soldered the IC holder (that holds DIP IC don't know the name) and the same problem!!! so now I just have soldered the input pin and IC holder and even did not place IC. and I can not get the voltage.....What on earth could be the problem with placing that holder. Why without it is fine and with it is wrong.....
Something is seriously wrong with board probably......