Maxon OD808 Reissue - almost no output.

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Maxon OD808 Reissue - almost no output.

tracer03
This post was updated on .
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Built this one, and had the very low output issue that someone else had - almost no output.

Checked pots, all component values, replaced a couple of resistors for good measure.
Knifed strips, checked continuity, everything seems okay.
Tried different transistors, tried JRC4558, RC4558P, TL072, no luck.
Pulled ICs and Transistors from working builds that I know worked, still low output.

Maybe someone can find something I've missed?

Transistor voltages
Q1
C - 9.04
B - 3.243
E - 2.7

Q2
C - 9.0
B - 3.34
E - 2.94

IC Pin Voltages
1 - 4.57
2 - 4.78
3 - 4.66
4 - 0
5 - 4.58
6 - 4.58
7 - 4.58
8 - 9.03

EDIT: in case anyone is wondering, the 47u cap *is* oriented correctly (as are the others) - the marking just makes it look incorrect.

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Re: Maxon OD808 Reissue - almost no output.

tracer03
Bump - anyone?
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Re: Maxon OD808 Reissue - almost no output.

Zanius
Can't really tell but 90% of the time there is a short on your board. Inspect closely and run a knife across all the rows to make sure there is nothing there!
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Re: Maxon OD808 Reissue - almost no output.

bigzed900
This post was updated on .
In reply to this post by tracer03
Where you have made cuts by drilling holes just check that the strip is completely cut. I had a thin slither of copper still attached which drove me mad until I eventually spotted it!! Looking at the pic of the underside of your board going from top left check 7 across 4 down!
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Re: Maxon OD808 Reissue - almost no output.

velouriafx
Check the CUT in the bot line. These veros has connections under the paint in the top and bot lines
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Re: Maxon OD808 Reissue - almost no output.

tracer03
velouriafx wrote
Check the CUT in the bot line. These veros has connections under the paint in the top and bot lines
Thanks - that was the culprit. I've gotten in the habit of using my meter on the continuity setting to check that all my cuts are complete before I start soldering, but I must have missed that one. Sliced the track with an Xacto, reflowed a few joints and I have tube-screamery goodness!