Yamaha c80 - accessing the push button input selector switches to clean?

[3-way]

Short of spraying F5 everywhere between the board / front panel in the hope that some gets into the switches...
Anyone ever successfully removed & replaced the front panel?
Can the front panel be removed to get a peek at the infamous input selector switches that yamaha chose to hide so well?
Do the switches stay with the unit when you remove the front panel?
Or do the spring loaded switch covers come off with the front panel?

 

[avionic]

Anyone ever successfully removed & replaced the front panel?

Yes At least 25 or 30. Probably more.

Can the front panel be removed to get a peek at the infamous input selector switches that yamaha chose to hide so well?

Yes

Do the switches stay with the unit when you remove the front panel?

No. You have to unplug 10 little cables.

Or do the spring loaded switch covers come off with the front panel?

Yes, they are captive - (glued) to the front panel. But first you have to remove the small switch circuit board from the rear side of the front panel.

I think the service manual has disassembly instructions.

 

[avionic]

Ideally the little tactile switches need to be partially disassembled to even think about deox-it getting to where it will do any good.

Be aware there is a very, very tiny, spring loaded (Jesus) pin that needs to be secured. It's about 2mm long and the diameter of a sewing needle.

 

[Soundscape]

My 2 cents: The 10 cables are numbered by the factory on the connectors and the board, which is very nice and easy.
There's 2 or 3 fine thread screws holding the faceplate to the chassis, remember where they go. IIRC there's arrow designations for the fine ones. All the other screws are coarse thread. You'll see what I mean upon reassembly..."why don't this one fit right?" lol .

All the control knobs under the flip door need to be pulled off. Volume control doesn't have to be removed, but if you do, the knob has a small hex screw on the side.

The small input control board with the tactiles has 5 screws. 4 on the corners and 1 dead center. I almost broke the board once from not noticing the center board screw. Have fun. Not too hard at all.

 

[nakmandan]

What others have said. The switch assembly is the same for the C-60/65/80/85 preamps. The front panel isn't hard to take off/apart at all. The tactile selector switch assembly is a major fault in these preamps, causing a lot of intermittent/dropped/reduced/distorted signals. I am no stranger to taking switches apart, having done it many times on many different brands and models. However, these particular switches are something else! I tried one, got it apart and cleaned, and could not get it back together and working smoothly. There are four vertical slides in each switch. They like to fall out or move out of position while you are trying to get it back together. I ended up buying an extra switch from Avionic to replace the one I couldn't reassemble, and then spent probably a good half a can of Deoxit D5 saturating the switch assembly and working each switch back and forth a few thousand times (OK, well maybe not a THOUSAND, but a lot!). A really messy job! Wear gloves! Have lots of paper towels ready!
So in conclusion, I now just spray a ton of Deoxit multiple times in the switch assembly rather than try to disassemble, clean and reassemble each switch. Not as effective as full disassembly and cleaning, but it guarantees you won't ruin one or more switches trying to reassemble them.
I still have that extra switch, maybe I'll try it again and see if I can manage a successful reassembly. if I can do it without too much fuss or drama, then I'd entertain the idea of doing all of them at the pre's next rendezvous with my bench.

 

[Asmodeus2112]

Ideally the little tactile switches need to be partially disassembled to even think about deox-it getting to where it will do any good.

Be aware there is a very, very tiny, spring loaded (Jesus) pin that needs to be secured. It's about 2mm long and the diameter of a sewing needle.

Yeah, from experience, be very prepared if you are going to open these. Work in a well lit place over a bench. Very small pieces that are easy to mess up, but they can be opened.

 

[Soundscape]

I've done 3 of these & still don't have the stones to take apart the input selector tactile switches, lol. The C-80 still works good after 5 years. Wasted most of a can of D5 on it with alot of switch cycling. Was hoping to find a way to do this without wasting so much CAIG sauce. Pricey ya know?

So the C-60 I did last winter worked well with alot less waste. Here was my recent recipe:
1.Gave em a good squirt with D5 and let it simmer an hour.
2.Then blasted out the cheese with electronic parts cleaner.
3.Then finished it off with D100, the overpriced bottle version that comes with the needle point applicator, & basted every possible slit.
4.And yes, lots of cycling...until...

Music is served!

 

[avionic]

I pulled one off of a parts unit C-xx. Disassembled it. Just to see what was involved. To get them cleaned up. Hence post #3. I'm still looking for that damn pin.

 

[Soundscape]

I pulled one off of a parts unit C-xx. Disassembled it. Just to see what was involved. To get them cleaned up. Hence post #3. I'm still looking for that damn pin.

Um...why is it called a Jesus pin in post 3 when it's so unforgiving?

 

[avionic]

Um...why is it called a Jesus pin in post 3 when it's so unforgiving?

No. That's the first thing you say when it frickin sub-orbital launches to parts unknown.. OH !! Jesus $#@&.