Hi everybody,Please help me Carl Moreland

[nokia6230i]

PLEASE HELP me Carl Moreland ,Pease help,my Hammerhead rev C one day functoin,one day not fuction ,one day funtion,one day not funtion and now not function,I know electronics.Voltage output it's OK

IC2 (pin 1 = +5v), IC3 (pin 3 = -5v),

and IC4 (pin 3 = -5v),

IC5 (pin 1 = -5v), IC11 (pin8 = -5v), and IC12 (pin 8 = -5v). The

output of IC5 (TestPoint 1)

Frequency and Pulse WidthIt should fall between -0.25 and

-1.25 volts, and be roughly -0.5v,Voltage is OK,But no FUNCTION,I have changed every IC,verifyed every Q,one day function ,one day not function. I dont have oscilloscope.
I make BARACUDA PI is functionable,is OK,But HAMMERHEAD not funtion.
Hammerhead whistle.....PLEASE HELP,Thanks in advance I give a beer...

[nokia6230i]

I found a problem, but still not working has changed the sound and setting potentiometers change sound but not working. On approach hand over,assembly detects the sound change.
Coil and MOSFET IRF740 not react Q3 checked and replaced, if the sound changes hands on approach to electronic assembly, Please Help ...

[Qiaozhi]

Without an oscilloscope you have a very difficult task on your hands.

[nokia6230i]

Without an oscilloscope, can not do anything ? ...

[nokia6230i]

I think ic 74HC221 arrive Tuesday or damaged other 4 pieces and I have to replace Them and communicated results. Sorry for my English.

[Carl-NC]

Take a lot of measurements when it's working, and then again when it's not working, and try to see what is changing. You really need an oscope for debugging.