Yet another GGG ITS8 debugging session :D

[Plinky]

 Trying to build an ITS8 Tubescreamer clone from GGG (http://www.generalguitargadgets.com/index.php?%20option=content&task=view&id=90&Itemid=118).
Let me list the immediate concerns before I start with voltage readings. I'm thinking if I fix this problem first, it just might solve my problems.

Symptoms - Effect bypasses properly. No LED or sound when engaged. Battery is getting VERY HOT!! I have just checked the Input and Output jack connections, as well as the battery clip and DC jack connections, and the 3PDT switch connections and all look identical to the parts layout (no mods done...yet). I took D4 and R23 out of the loop (thought they might be inop), but that made no difference. I can usually follow instructions with the best of them, but for some reason, this one is giving me fits. Any help would be greatly appreciated.

[$uperpuma]

if the battery is getting hot, there is most likely a short somewhere. solder bridges are the first place to look, make sure solderis only where its supposed to be. Another thing is to make sure your switch is oriented correctly so that the correct things are making contact when you are switching

[Cardboard Tube Samurai]

Yeah, sounds like it's shorting to me too. Do what he said pretty much ^^^^

[Plinky]

Haven't found any accidental solder bridges yet. I found some parts of the trace that were open (fixed them, problem still exists). I checked the switch again - looks ok to me (orientation similar to my EA Trem that now works  ). Starting to wonder if a component on the board is shorted. Checked the diodes (pulled one leg out) - ok. Tried replacing the IC - no luck. Replaced the transistors - still there.

I may just etch another board (wasn't too happy how this one came out compared to the others). I have enough spares to repopulate another board. Any other ideas before I throw in the towel on this one???

[jlullo]

plinky, this happened to me on my first ts808.  i had my switch rotated 90 degrees.... are the holes on your lugs up and down, or left to right?


sorry.... i didn't see that someone else already suggested this 

[Plinky]

Holes are facing N & S, just like the layout on the above URL in the 1st post.

[Plinky]

Well, all the pots, switches, and such worked fine. There must have been a shorted component on the PCB.
I didn't feel like looking for a needle in a small haystack, so I decided to start all over from scratch (I bought
double the parts, so I had plenty to do another one). I used all the outboard parts (switch, pots, etc.) from
the first attempt, but I took my time and measured and confirmed everything before I soldered a part in
(finally learned about that patience thing ). Amazingly the 808 worked perfect on the first try, give a little
RFI which should go away when I enclose it. Very impressed with this effect - sounds just as good if not
better than my Maxon OD-808, and I haven't even started modding it.

1. Exposure process.



2. Developing process.



3. Developing completed, PCB ready for etching.



4. Preparing etchant. Mocha-Ferric Chloride anyone?



5. Etching in progress.



6. Etching completed, PCB ready for trimming and drilling.



7. PCB population in progress (sorry, a little blurry)



8. Population complete, switches, LED, power inputs, and pots connected



Waiting on the enclosure to put everything in, then it's time to rock.
I'll post some sound clips when it's completed.