Centre section compressor backwards?

[MarconeMusic]

Hi.
I can’t add a video here it seems. But basically I am noticing after I had the centre section out that the compressor is behaving incorrectly from what I know.
It may have been this way forever. But I’ve just noticed with a test tone.
We injected a tone, compressor off, tone is +4.
Compressor on at 2:1 setting and the signal reduces. 
Switch to 4:1 and the output goes up, the compressor meter shows less compression.
Switch to 10:1 and the output goes up again and the compressor meter shows even less compression....

Huh?

[MarconeMusic]

Seems its the Knee, Acting normal.

But i did find an issue id love some 'advice' on .

One of the 26 cards while in compression 'jams' the compressor hard. So if the channel is injected with a Tone, the compressor turned on, the compressor pushes reduction to the limit. Regardless of threshold. The other 26 cards act normally.

Any ideas?

[Chris Simon]

If you move the '26 cards to different slots in the 651, does the problem follow the card? If the problem persists regardless of what slot the suspect card occupies, examine the sidechain path on the card. Check A2, T5,T6, and T7, and the FETs and diodes. If a particular slot being populated by any card sets it off, check the connections to the 651 motherboard, especially around pins 33 and 42.

[MarconeMusic]

Wonderful! Will do!

We have a bad card for sure because one of the cards makes a fulll compressed signal on turning the compressor on.  Threshold knob doesn’t change anything  with that card. Full on always.
I’ll figure that one out.  It got moved to the back buss for now.