MOTM

Chances are greater than 50% that your problem is something simple 
like a bad solder joint, or IC in backwards. I had two modules that 
had completely dead outputs when I finished them. The problem? Too 
much heat had caused the coax insulation to melt just enough to short 
the output cable. I had to learn to modify my coax installation 
technique!

Moe

--- In motm@y..., bruce@s... wrote:
> I have a question about the troubleshooting guide in the back of 
the 
> MOTM 300 instructions.
> 
> The third check box has several lettered steps.  Step (b) says to 
> check the VX voltage, and make sure it is close to +4.8V, and 
mentions 
> the right side of R3.
> 
> Looking at the schematics, it looks like R3 is involved in the fine 
> tune voltage, whereas R37 is closer to where one might find VX.
> 
> Comments?
> 
> Oh yeah, I have an MOTM-300 that is not playing nice at the 
moment.  
> All of the voltages seem to check correctly (with the exception of 
VX 
> as noted above), now it is down to verifying that all of the 
> components are in the right spot...
> 
> Part of me is wondering about O-Scopes and if that might help me 
find 
> the trouble sooner.  There is no sound at all out of the module, 
> except from the pulse jack, if I turn the coarse tune knob to just 
the 
> right spot, it outputs noise that can be changed by moving the PWM 
> pot.  8-)
> 
> Wahoo! (translation: this should keep me occupied for the next 
couple 
> of nights)
> 
> Bruce