Hello GH,
Most of us already had fixed non-clicky Cherry MX or chattering switches before. However, I would like to share some of my experiences on fixing non-clicky Cherry MX and chattering switches (with pictures) in order to help who are looking for a solution especially new members.
When dealing with keyboards, we may accidentally or intentionally face some troubles with clicky switches like Cherry MX Blue. Something like dust, moisture, cooking oil, high viscosity lubricant... may result a lost of clicky on Cherry MX Blue.
For example, if we spray or drop high viscosity lube like Lubriplate FMO 350 or Super Lube Silicone Oil to Cherry MX Blue, it is very high chance to make the switch no longer clicky.
Heavy solutions (after desoldering switches)
Solution 1:Using WD40 (try to use the original one - Made in USA - there are many counterfeit if you are living in Vietnam like me)
Well, WD 40 is good enough to fix the problem but it is not perfect because it still has lube. The Cherry MX Blue will have clicky again but the switch is like a mess with a lot of low viscosity lube inside and outside. And that will only attract dust particle.
Solution 2(better one)Using 3M High Power Brake cleaner
I tried this several times. It is very good on cleaning grease and oil. It can clean WD 40, RP7, SuperLube oil, Lubriplate oil, Silicone oil, ATF oil ... perfectly. For Dupont Krytox, I only tried on Dupont Krytox 205 but I need to use a brush in order to clean it, so I'm not 100% sure if it really works on all types of Krytox.
In order to wash it, I use a small inox dish. The 3M High Power Brake cleaner is safe for Cherry MX plastic (POM?) so we don't need to worry about it.
After waiting for about 5 minutes, I use hot air at 100oC to dry it (if you don't have hot air, you can wait for about 10-15 minutes)
The result is pretty good, all grease and oil are gone.
Everything is clean and dry. The contact-leaf is even shinier than before.
* Indeed, you can spray 3M High Power Brake directly to your keyboard without desoldering but I would not recommend because it is not safe for ABS plastic.
Light solutions (without desoldering switches)
This solution is only for fixing small issues. For that, we can use authentic lighter fluid (you can also use other light solvent like isopropyl 70-95% unless it is unsafe for plastic) . This one is easy to find anywhere in the world. A few drops of lighter fluid to key switch can fix some minor issues like random key chattering or non-clicky Cherry MX Blue with dust or moiture.
Hope these solutions can help you to clean and recover the clicky of your Cherry MX Blue.
Edit: adding close-up images