Author Topic: Another strange VCA issue **SOLVED**  (Read 1333 times)

oyanliz

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Another strange VCA issue **SOLVED**
« on: March 16, 2018, 08:04:45 AM »
Hi all,

One of my channel strip stopped working throught VCA in mixing mode.

Details:

- VCA fader it is working fine (channel strip slot it is ok)
- 82E13 VCA card swaped and working fine
- I measure +- 17.8 on pins 29 and 30 of the 82E13 card
- Multiplex card is removed and it is jumped in the motherboard correctly (continuity between pins 17 and 20 on the 82E13 card)
- I measure 4.8v on pin 35 (82E13 card)
- There is continuity between pin 35 of 82E13 card and pin 74 of the lower bus card pins of the motherboard
- There is signal in the insert and group output (VCA fader working fine in record mode and direct button, swhitched on)
- I measured the voltage on pins 17 and 20 (connected between them for jumping the multiplex) when moving the VCA fader and I get 5v-0v.

I check the motherdboard tracks twice, but I do not see anything wrong.

I asume that the 82E149 amp card it is ok as the group output card (I have swapped all the cards and I also get signal in different points, as mentioned above, so...)

I would apreciate any comment.

Thanks in advance.

Best regards.

Oihan
« Last Edit: March 25, 2018, 09:54:04 AM by oyanliz »

Chris Simon

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Re: Another strange VCA issue
« Reply #1 on: March 16, 2018, 03:10:24 PM »
A few things you could try. Confirm that you have signal coming in to the Group card at pin 45. In Mix mode, do you have signal exiting the card on pin 44? If not, and the Group card works in other strips, perhaps it's the Logic card not switching the signal to the Quad buss. Check IC14 on the group card. Do you have signal on pin 3 (input) and pin 6 (output)? If there's signal coming out of pin 44 on the Group card, then there really only the Float switch before the Quad Pan to the Quad bus. Those switches do sometimes fail.

As always, good luck.

Chris

oyanliz

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Re: Another strange VCA issue
« Reply #2 on: March 16, 2018, 04:01:03 PM »
Hi Chris,

I also swapped group and logic cards yesterday. I will check the pin socket of the group card and the quad pan switch.

Thanks as always.

Regards

Oihan

oyanliz

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Re: Another strange VCA issue **SOLVED**
« Reply #3 on: March 25, 2018, 10:04:24 AM »
Sorry for the late reply. The console has been working all the day these days so I could not make tests with it.

After checkin all the voltages of the group card pins and check the mother boardtracks again... I decide to replace the "Float" switch. I had 2 problems and they were failing randomly, so it was not easy to find the issue. The "float" swhitch was wrong and the input amplifier card "line in" is failing sometimes (it could be an IC). So after replacing the "Float" switch, now is working but sometimes is failing the "line input" signal. I will find the failing IC next time stops working.

Chris, thank you very much as always.

Best regards.

Oihan