Parkside Cordless Multigrinder PFBS 9.6 A1 (Lidl) - overheat repair

I got this multi-grinder thing from Lidl about 18 months ago. I think I paid £20 for it.

It's ok, but I don't think it's anything like on a par with a Dremmel (which I intend to buy as soon as funds permit...). Anyway, I was using my multi-grinder the other night and to be fair, I was asking a lot of it (and, as things turned out, too much of it). I thought I was trimming some low-density fibre board but on closer inspection, it actually seemed to be some sort of laminate. Anyway, I'd started the cut so thought I'd persist with it. After about a minute at full chat the motor simply stopped. All the charge lights were still working but the unit was basically dead. There was also a fried-electrics smell in the air. I let the grinder cool down but it still didn't work. Naturally, I then took the grinder apart for a look:

The grinder is in two halves. Remove the five self-tapping screws, the end collet, and the wrist strap. Then break open but keep a hand or finger over the button for the spindle lock as there's a spring under there which will ping off if you're not careful...

With the grinder in half, one problem was immediately apparent. The (what I now know to be) motor speed controller (NCE50N06) had got so hot that the solder around it had melted and it had slipped off its pad!

That was a couple of weeks ago. Tonight I had a spare hour so I got my soldering station out and hit the chip with some hot air. It's solder melted (again) and I re-positioned the chip. I then re-soldered it and partially rebuilt the tool so I could stick the battery back in and test it. It worked!

So, it's now all back together and working fine. Easy!

More soon, no doubt...

D