MOTM

My thoughts were along the same lines, but the IC's are pretty easy 
(for me anyhow) as they were made to line up the same direction. I had 
some of the via holes had not been flowed all the way through last 
night, correcting that did not modify the behaviour.

I am going to run this thing the way I would as a crusty old avionics 
tech (hmm...)

But as Paul mentioned earlier the place to check things out would be 
the Sawtooth first, and I have this fear that I may have cooked one of 
the nice custom Q's that came with the kit.  The smaller one (Q2?) 
really did not want to get soldered in correctly, and I may have given 
it too much iron.  

That is the place where I will start anyhow.  Glad that the theory is 
in there too, makes it much easier to figure out.

Now to hunt ebay for an O-Scope

Bruce

--- In motm@y..., mate_stubb@y... wrote:
> 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