Focusrite Red 3 HELP

[originalscottyg]

I just replaced a switch on a Focusrite Red3.  By far the most difficult chassis to work with that I have ever come across.    The switch replacement was fairly straight forward and went well despite trying to work with the chassis.  In the process of disassembling/reassembling the chassis to get to the switch, which was on the bottom PCB (lower channel Auto Release switch), I dislodged 2 round, black plastic disks (about 1.5" diameter).  I am assuming that these were in place to protect something from contacting the chassis or other circuitry.  But I didn't notice them till I was almost done and don't know where exactly they came from.  Now that the unit is reassembled, the Compressor In and Limiter In switches are mutually exclusive.  Rather I should say that the LED in the Limiter In switch goes out when the Compressor In switch is engaged.  I haven't yet (booked up until next week) checked to see if the Limiter circuit is actually being defeated or if it is just the LED that is being shorted or deactivated in some way.

To give some background... the unit was powered up waiting for a session.  I left the room for a few minutes, and when I got back I heard a rapid clicking/zapping sound which I think was a relay triggering repeatedly.  I powered the unit down and let it cool down a bit.  After the session, I powered it back up and the clicking didn't occur again, but the Auto Release button on the bottom channel wouldn't stay latched.  This occurred with the unit power up and power off.  The replacement switch works fine now. I didn't notice if the Limiter switch behavior was happening at this time, because having the limiter in and then pressing the compressor in button is something that I would never usually do.
I haven't been able to find a schematic (I have heard that Focusrite keeps them secret).  So if anybody has any experience with this unit and can offer any insight, I would greatly appreciate it!!
Thanks.

 

[radiance]

Some photo's would help...

The switches can go in multiple ways...should remember the orientation when disassembling. Two pins are for the lamp and the two others connect to the switching element. When these are reversed (can't remember if this is mechanically possible) you'll get s short (instead of the resistance of the lamp) when the switch is pressed.

Yes...first time disassembling these is a royal PITA!!

 

[radiance]

http://www.thermalrelief.com/TTT001/

 

[originalscottyg]

Thanks for the responses, radiance!!!
And thanks for the link: I didn't realize that the xlrs could be removed from the back panel so easily.
Sorry I couldn't reply sooner, but I've been booked solid.

So I checked the orientation of the switches and all was correct.  If they are put in backwards the LED doesn't light at all.  As I said, both the Compressor In and the Limiter In switches would light up independently, it was just that the Limiter In LED would turn off if the Compressor In switch was on.

So here's where the story takes a turn.  After testing the switch orientation a second time to double check (I had initially thought that might be the problem) I put the unit back together and put the knobs back on and...
Viola!!  The unit works perfectly.  I am not sure what the problem was, but I will definitely keep an eye on it.  Perhaps in it's disassembled state, something was touching/shorting somewhere?!? I just tested it in the studio with a voice track: it sounds just fine and all the controls behave as they should. 
Also, I believe the 2 black disks I referred to are actually part of the insulated covering from a couple of caps in the power supply where the plastic shrinkwrap label on the cap has shrunk back a bit.  The caps don't look bulged out or failing.  I am sure they probably do need to be replaced eventually, but the unit is working fine now and I really don't want to have to take it apart again.
Anyway, thanks for the replies, radiance.
They were much appreciated!!!!