Need Help to clean circuit board

JonAsad · Oct 10, 2021

Hi,
I have opened my sunroof and there is a circuit which is blacked with some stuff, it the circuit where the sunroof control buttons slides to open or close.

I tried using contact cleaner but it didn't work.
If i scratch it with a sharp tool its getting off, but i am afraid it would damage the whole thing. I don't know how to clean it.

I am doing it as DIY. Since i am on low budget and can't afford an expensive replacement of the whole module.

Picture attached kindly help.

[ElectriciansForums.net] Need Help to clean circuit board

P. S Sorry about my nails.

freddo · Oct 10, 2021

I usually use brake cleaner applied to a swab for tough dirt/grease. Don't spray it directly on the unit to be cleaned as it can degrade plastics. The stuff is likely old hardened grease. once it is clean replace the grease with a thin layer of electrical contact grease. Don't forget to clean the other part with the contacts on.

telectrix · Oct 10, 2021

you can buy a cleaning brush. it's like an artist's paintbrush but has mildly abrasive fibreglass bristles.

RS PRO Fibreglass PCB and Flux Brush | RS

uk.rs-online.com

Lucien Nunes · Oct 10, 2021

Sometimes a splinter of wood is good for scraping off corrosion and hardened grease. As an alternative to using aggressive cleaners, it can help to wipe the surface with WD40 and let it soften the deposit, and wipe again every 15 minutes until it has loosened and just wipes off.

The switch contact surfaces are plated - try to avoid peeling or scraping the plating off. It might have corroded through and you might have to live with that, but preserve it where possible.

JonAsad · Oct 19, 2021

Hi,
Thanks for your answers, i managed to clean it with a thinner.
Can i apply a small layer of lithium calcium grease on it?

freddo said:
I usually use brake cleaner applied to a swab for tough dirt/grease. Don't spray it directly on the unit to be cleaned as it can degrade plastics. The stuff is likely old hardened grease. once it is clean replace the grease with a thin layer of electrical contact grease. Don't forget to clean the other part with the contacts on.

Avo Mk8 · Oct 19, 2021

JonAsad said:
Hi,
Thanks for your answers, i managed to clean it with a thinner.
Can i apply a small layer of lithium calcium grease on it?

I don't think white lithium grease is suitable for contacts (it's insulating). More suitable to repel moisture from battery terminals etc.
You want grease specifically for switch contacts: