Help debug a Green Ringer

Started by carrejans, May 30, 2010, 09:37:49 AM

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carrejans

Made this a year ago; not in a box, and it worked.
Now I put it into a box, and doesn't work at all.


1.Doesn't produce anything

2.Green Ringer

3.used the pcb from Tonepad: http://www.tonepad.com/project.asp?id=46

4.No mods

5.no parts substitutions

7.Some measurements

Q1 (2N5088)
C = 8.5V
B = 1.7V
E = 1.37V

Q2 (2N3906)
C= 0V
B= 8.55V
E= 8.93V

Q3 (2N5088)
C= 9.05V
B= 4.0V
E= 3.65V


It seems there's something wrong with the Q2. I replaced it with a new one; but didn't make any difference.

Hope you guys can help me out...
Thanks.

petemoore

Reverse the input and output?
  ..Audio probe.
 
Convention creates following, following creates convention.

PRR

#2
Q1 is not making sense. Q1 Collector should be nearer 6V than 8.5V.

Re-check the 6K2 (Blue-Red-Red-Gold) and 18K (Brown-Gray-Orange-Gold) parts. Mixing-up Red and Orange is easy, and a 1-point-8-K at "18K" (or 62K at "6K2") would match your readings.

Lift Q2 Base and see if Q1 Collector voltage changes.
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carrejans

Thank you guys!!

PRR, you made my day. You were correct. I used a 62k resistor in stead of a 6.2k!!

(so it probably never worked at all; I thought it worked when I made it about a year ago  :icon_redface: )