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Loophole issues (solved)

Started by bigrigg, April 01, 2012, 12:03:10 AM

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bigrigg

Hello and thanks ahead of time:

Loopole
Problem
Green (play) LED always on.  Will slightly dim when detune switch activated.
No regular playback recording

Red LED works properly with record switch.
Detune seems to play back a "detuned" recording of sorts.  It will play back and slow down until it pretty much stops.  I have had the odd regular record work briefly.
Sometimes the LED's will flash?

All pots (4) effect the detune playback.
Bypass works. Clean signal.

Here are the DMM readings.  I think I took these with all switches off, but how do I know?  All pots were turned fully clockwise.

Pwr at DC jack 9.32 v / ground 0
pwr at board wire 9.32 v / ground wire at board 0

IC 1
1 4.66
2 4.66 (plus radio station comes through, nice)
3 4.65
4 0
5 9.32
6 4.66  
7 4.66 (plus radio station comes through, nice)
8 4.35

IC 1
1 2.29
2 2.28
3 6.87
4 0
5 7.9
6 7.9
7 8.03
9 8.03
10 2.29
11 2.28
12 0
13 0
14 0

IC 3
1 0
2 0
3 0
4 7.9
5 0
6 0
7 0
8 0
9 7.9
10 7.9
11 0
12 0
13 0
14 0
15 8.03
16 7.9
17 0
18 8.03
19 2.28
20 0
21 0
22 0
23 0
24 0
25 0
26 0
27 8.03
28 0

IC 4

1 4.65
2 4.66 (radio quiet)
3 4.66 (radio quiet)
4 0
5 4.45
6 4.66
7 4.66
8 9.32

REG 1

input (collector) 9.32
base/gnd 0
output (emitter) 8.03

I also don't find any shorts to ground etc on the trace side.
Thanks again very much.



bigrigg

I'm not opposed to begging??

bigrigg

pedal shorting out due to tears    :'( 
does anyone have answers or Kleenex?

gtr2

sorry, haven't built one and haven't even ventured to look at how it functions.

Good luck.  Hopefully someone who has some experience with this circuit will chime in...

Josh
1776 EFFECTS STORE     
Contract PCB designer

JakeFuzz

Replace or check the regulator. You should be getting 5 volts out. Something may have shorted and blown that up. I wouldn't do anything until you get the 5 volts off of that thing. 9 volts may fry the ISD

JakeFuzz

Also check the trace connections at D1 and D2, they look like they might be shorting together.

bigrigg

Quote from: JakeFuzz on April 03, 2012, 03:14:51 AM
Also check the trace connections at D1 and D2, they look like they might be shorting together.
Jake Fuzz....how do I love thee?  Let me count the ways.....one...replaced regulator for 5v output....two....cut trace on board between D1 and D2.
Yup....those are the ways.  You rock.  Thanks so much.  Works perfectly.  Will post in builds soon!

JakeFuzz

Awesome! Glad it works. I am looking forward to the build report.

gtr2

Glad J.F. could help you out!

He's the resident loophole guru  ;)
1776 EFFECTS STORE     
Contract PCB designer