# Can I resolder an insulated solder joint?

#### rambomhtri

Joined Nov 9, 2015
520
I'm fixing my electric tooth brush, and I think there's an insulating layer all over the IC.

Can I apply heat to one joint and use the solder it's there?
Notice it's a personal tooth brush, it hasn't to be a professional job.

I don't know if the solder and the insulating layer will mix up and then the whole solder is not a conductor anymore...

Thanks!

#### Alec_t

Joined Sep 17, 2013
13,315
It would be best to scrape the layer (conformal coating) carefully away from the immediate area/joint you need to solder.

#### rambomhtri

Joined Nov 9, 2015
520
Never mind, I actually mixed everything before you replied. It works, so although scraping the solder to remove the thin coating or layer is the best hing to do, it still works if you don't do it.

Dammit, Braun, you guys really don't want "expert" customers to replace your dead rechargeable batteries. It's was way too complicated to replace just a rechargeable battery, lol (I did it though). If I had taken the electric tooth brush to a repair electronic shop and tell them to replace the dead battery, man, it would have been like $50 or more. And a new electrical tooth brush costs less than$30.

By the way, I couldn't solder the damn solder wire to the new Amazon battery, it wouldn't stick. I ended up using tape, rolling it with force all around the battery, to guarantee a solid "joint" between the new battery and the cables that should be soldered on it.