Author Topic: Channel showing signal to VU without signal input  (Read 8462 times)

Kats

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Channel showing signal to VU without signal input
« on: January 15, 2013, 05:56:50 PM »
Odd little hiccup...

I just finished re-capping our 6KE and one channel is showing 0 VU on the meters even though there is no signal present. No sound comes out of the speakers and the channel seems to function properly otherwise. This is present even when the dynamics and EQ are off. This problem follows the channel.

I checked the cap orientation and all seems fine in that area.

Any ideas?

sintech

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Re: Channel showing signal to VU without signal input
« Reply #1 on: January 15, 2013, 06:45:34 PM »
Personally, I'd get the channel on an extender, then trace the voltage back from the VU meter. Meter input select will be the first place to look

sintech

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Re: Channel showing signal to VU without signal input
« Reply #2 on: January 15, 2013, 06:58:38 PM »


This 4KE so check your block schematic, I know the RG numbers are different on the G channel

sintech

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Re: Channel showing signal to VU without signal input
« Reply #3 on: January 16, 2013, 09:56:01 AM »
Thinking about it.. this happened to me once when recapping a channel amp, an unwanted DC voltage caused a small blob/splash of solder that was almost invisible to the eye.

Made copies of the schematics, and used a highlighter pen to mark the intruding DC, and this gave clues where to start looking.

This prompted my purchase of a Weller 'Through Hole Rework station'  8)


Kats

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Re: Channel showing signal to VU without signal input
« Reply #4 on: January 17, 2013, 02:14:53 AM »
Thanks for the tips. I'll have some time tomorrow to sus it out.

Kats

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Re: Channel showing signal to VU without signal input
« Reply #5 on: January 22, 2013, 12:31:33 AM »
It's always the dumb things...

Turns out I forgot to put C9 back in the VCA card.