Idea (and question) for cleaning 430W buttons contacts

[redbaron1982]

Hi,

Something that I'm trying to improve is the feel of the avionics buttons (mainly in the 430W). They are really hard to press. Which is not only uncomfortable, but also it adds to the work load when flying IMC.

I tried spraying contact cleaner on the side of the buttons, with no success. Which makes sense because the gap between the button and the from panel is small, and there is a rubber membrane underneath as well.

I saw a post in other forum that completely took the 430W apart to clean the PCB, which even being an electronic engineer I don´t feel comfortable doing (apart from being illegal for sure).

I don´t want to pay an avionic shop what I think is going to cost a lot of money (>1000usd?) to get it refurbished.

So I have an idea and want to share it with you to have your opinion (and maybe it can be helpful for some of you as well).

I thought of attaching a G25 needle (0.5mm outer diam) to the end of the plastic tube from the contact cleaner, like in the picture below:

The idea would be to perforate each button from the side to get underneath it and then send a small amount of contact cleaner down into the PCB.

I tested with a TV control remote (which the buttons are the same technology as the 430W) and didn´t break it. You can´t even tell there is a puncture in the rubber. The spray get out of the tip of the needle without problem.

So, what are your thoughts? More important this is if you see any risk of doing this.

Edited March 9, 2023 by redbaron1982

[Rwsavory]

I know practically nothing about electronics, but I do know that if your proposed method goes awry it may be a very expensive mistake. I would suggest you contact Bevan Aviation. They can probably do the repair for a reasonable price.

[MikeOH]

Sounds risky to me. You’re introducing an uncontrolled path for dirt and moisture to enter; could be a temporary “fix” that ends up worse soon after!

[PT20J]

I've never taken a 430W apart, but most modern keypads use a silicon rubber pad with molded in bubbles for each key between the buttons and the contacts and the flex of the rubber is what provides the springiness of the key. The feel is designed in. If it were me, I would compare it to another 430W. If it feels similar, I'd leave it alone. If it feels different, I'd either live with it or send it to Garmin for repair. But the flat rate repair for for a 430W is about $2K. At any rate, I don't see how contact cleaner is going to do anything.

Skip

[redbaron1982]

3 minutes ago, PT20J said:

I've never taken a 430W apart, but most modern keypads use a silicon rubber pad with molded in bubbles for each key between the buttons and the contacts and the flex of the rubber is what provides the springiness of the key. The feel is designed in. If it were me, I would compare it to another 430W. If it feels similar, I'd leave it alone. If it feels different, I'd either live with it or send it to Garmin for repair. But the flat rate repair for for a 430W is about $2K. At any rate, I don't see how contact cleaner is going to do anything.

Skip

There are good pictures here (https://onedrive.live.com/?authkey=!ABSujBZG6gUB7g8&id=8712D784B64E679!95504&cid=08712D784B64E679) from a guy that disassembly it.

Why the contact cleaner would help? The actual contacts are this small metal things that with time they get dirty from the same stuff that is used to protect the PCBs.

The problem is not itself the springiness of the key, but in my unit once you pressed and overcome the resistant of the rubber pad you need to continue pressing using the tip of your finger to actually make the button work. In the flight school were I used to fly there were 430W units like this (and some transponders as well) but there were others that once the button was depressed it would work, without having to put extra force on it.

[MikeOH]

If the design is metal dome as shown in the photo then, ultimately, the failure mode is the gold plating under the dome wears away exposing the base metal which oxidizes; cleaning, assuming you are even successful, will be temporary.

[redbaron1982]

Hey guys, I want to give you an update on this, just in case it might be useful.

First I want to clarify that I did take into consideration your comments and risks, mainly on creating a entry path for dust that could eventually make things worse.

I think this risk is not significant because the puncture is so small (and rubber tends to fill in back the puncture) that not even water goes through it. This is how vaccine vial works, you puncture through a rubber cap to get some of the liquid out, and you can do it several times.

So I tested today in the morning first  in the MX20 (that is an obsolete equipment that I wouldn't be too sad if it breaks) and it didn't damage the equipment and the buttons were much more responsive.

With this added confidence I did it in the G430 and same result, unit works perfectly and buttons are very responsive.

Now the only thing to see is for how long the buttons will continue to work.

Edited March 10, 2023 by redbaron1982

[DonMuncy]

On 3/10/2023 at 9:29 AM, redbaron1982 said:

Hey guys, I want to give you an update on this, just in case it might be useful.

First I want to clarify that I did take into consideration your comments and risks, mainly on creating a entry path for dust that could eventually make things worse.

I think this risk is not significant because the puncture is so small (and rubber tends to fill in back the puncture) that not even water goes through it. This is how vaccine vial works, you puncture through a rubber cap to get some of the liquid out, and you can do it several times.

So I tested today in the morning first  in the MX20 (that is an obsolete equipment that I wouldn't be too sad if it breaks) and it didn't damage the equipment and the buttons were much more responsive.

With this added confidence I did it in the G430 and same result, unit works perfectly and buttons are very responsive.

Now the only thing to see is for how long the buttons will continue to work.

You have more guts than I do. I applaud you for effort and innovation. 

After several more folks have tried it and report that it works for them, I might be tempted to give it a try.

[Mark89114]

Hell if it doesn't work just send it back to Garmin after cleanup and claim ignorance.   That is what flat fee repairs are for.  Doubtful they would notice a needle prick in the rubber.

 

[redbaron1982]

Just to add something, in case someone else is crazy enough to give this a try:

 * Make the punctures right in the letters. It seems that the rubber is transparent, paint with black. If you puncture the black part you'll remove the black paint and whenever the lights are on you will get a bright spot there. If it happens that, you can fix with a sharpie.

 * When you press the trigger on the contact cleaner, make sure you first hear the liquid going in and wait for it to finish. If you don't hear anything it is because the tip of the needle is still in the rubber. If you take out the needle before all the pressure is released you will get a splash of contact cleaner that you will have to clean.