Need fresh eyes (help!) :)

[Heath]

Hi, folks,

I haven't been around much the past little while due to some diabetes complications.  So now I have nerve damage in my right arm, numb fingers on my right hand, and my vision is a bit iffy.

So, of course I try to build one of the most complicated circuits on here.  The Mutron Phaser II.

..and of course it's not working.  So I'm going to try some newbie help begging.  Please keep in mind that I am on drugs at the moment, so I am struggling a bit to remain coherent in my descriptions.

Symptoms:  LEDs are not flashing/blinking.  They are just solid on.  Tweaking the knobs and one of the trimmers affects the brightness, but that's it.

I actually printed the layout and glued it to the vero (ala dbat69) because I knew it was going to get complicated.  So all of the jumpers, cuts, and components appear to be in the exact right place.  I tested all capacitors before soldering.  I've tried it with both JRC4558s and TL082s.  I've tried replacing the transistor.  I went over the cuts and tracks with a jewelers loupe and see no bridges.  Went over all of my soldering points with the same and they all look good to me.

The ONLY thing I can find that is odd is the charge pump:

I built it and attached it to the main board.  I'm using a 9v regulated supply.  I get +9v where I should be getting it, but at the -9v out from the charge pump daughter-board, I'm getting right at about -7v.

Here's the weirdness... I thought maybe I had made a mistake on the charge pump board, so I snipped it off and built another.  I measured it before I hooked it up.  I connected my ground and 9v in using my test box.

I get +9v/-9v.  Perfect.

I attached it to the main board: +9v/-7v.  

Just to try *something*, I removed the ground from the main board (I had all grounds going to the same point and wondered if maybe I had some sort of *powersuck* going on) so that the charge pump board was connected to the 9v in and Ground and the +9v/-9v leads connected to the main board, but removed any other ground connections coming from the main board.

+9v/-8v.

I re-connect the main board/pot to ground.. +9v/-7v

I don't know why the crap this is happening.  Is it normal?  Could a low/mismatched -v input be causing the LEDs not to flash?

Here are some pictures if someone wants to take a stab at it (sorry about the crappy pictures... I tried to get with and without flash since neither seemed to work really well) :/













(tried with both the Maxon and 7660s chips, same results.)


My eternal gratitude in advance, of course.  

Did I mention it's a real bastard soldering with numb fingers?



 

[JaviCAP]

Can't see anything obviously wrong, but if the leds are not flashing, you have a problem with the lfo, IC6 for this part.

I'd check connectivity, voltages and so on from Depth 2 row (to 68k, ic pin 5, ic pin 7 to base of the trannie, and from emmiter  to + on the leds.

If you can't find anything wrong, you'll have to go from Depth 2 backwards, Rate, and so on.

Do you get any (dry) sound? If you get no output, the most probable is a unwanted connection to ground. Have you checked that all IC's have +9 on pin 8 and -9 on pin 4?

J.

[Heath]

Thanks, Javi, I'll put that advice to work as soon as I get home.  What sucks is my vision gets really weird when I try to look at stuff up close.  Hopefully it's just temporary.  The illuminated jeweler's loupe I bought for $5 has become a Godsend. :)

[rocket88]

i can't offer any advice on this circuit, as it's on my list and haven't had a chance to build it, but i just wanted to say that i hope you get better, and that i'm sorry to hear about the health things coming up.

[jubal81]

I've been struggling with this circuit this week, too. I found the opamps I was using were too power hungry for the charge pump, so I put in some plain 072s and there was a lot less power sag and it started working like it should - other than the other issues I'm having with some mods I was trying to implement.

[ξεναγος νεκροπολης]

hope you'll be ok with your health mate! i was wondering where you are man!
welcome back!