Removing components off original DMG boards

[ylwsub68]

I had trouble with this too. I dropped more and more solder but it still wasn't coming off. Eventually I got it, but I ended up pulling off the plastic coating of the board as well as some of the copper in that area, leaving some really ugly scorch marks. Ouch. Luckily, none of the traces for the buttons run through that area, but I really wish that chip had come off cleaner.

I, too, have an ultra cheap soldering gun that I had for 4 or 5 years without opening, and it never seemed to get hot enough. Somehow I think the prolonged tugging and pulling on the chip made the board itself give out instead of the pins breaking.

[Misel]

In my experience a dirty tip doesn't get as hot as a clean one. Maybe "resharpening" it with some sandpaper might already do the trick.

[Cannikin]

I had mine at 350° and nothing was happening so I upped it to 400° and then the existing solder melted real nice. I finally buckled down and got myself a nice soldering iron a couple of years ago and I'm SO glad I did. I've got this one, which has since been retired, but I think it's just a re-brand of an existing model out there: https://www.sparkfun.com/products/retired/10707

[Popcorn]

Gonna invest in a new fancy soldering gun this week.

[crispy_tofu]

He's from the UK where they actually use a measurement system that makes sense.

Ooh, shots fired.

Mine melt pretty well on 275 degrees. 180 degrees will be a bit low

That's because of the thermal mass of the iron. The joint will actually suck up some of this heat until the solder melts (it's worse with bigger tracks/pads), which is why you need to set it higher than the actual melting point of the solder.

I can't say I've ever seen an iron with that design before. Maybe you should open it up and see if there's a model number inside.

Gonna invest in a new fancy soldering gun this week.

Keep us posted!

[Popcorn]

So, I knew I wasn't crazy! I called in the favour and took the dmg pcb to a production manager friend that runs an analogue modular synth company. I KNEW he would have the gear to help me desolder these components. I took it to him, and he brought me into his shop. He had this insane temperature-controlled professional desolderer. With this kinda temperature controlled digital readout and this built-in spring vacuum with some fume exit exhaust attached. It looked really fancy and expensive. After my past month playing with that ghetto hand-me-down (toy) soldering gun, I felt like such a lam0r compared.

Anyway, the point is, he was helping me desolder the pieces off the board. I had already completely destroyed the switch from burning the board completely through (by placing my iron on there for like minutes to try to get it off). So, he gets to it, and suddenly, my friend goes, this is weird. He turns up his state-of-the-art desolderer. And says, something is odd with this board. He ended up having to go over 700F to melt that solder. When I looked at the display, this was after the fact and it was starting to cool off. It was over 450C+

That's hella hot. Fortunately, the volume knob and the headphone jack came off like they were brand new. All of the stickers are still on the back, clearly visible. Amazing considering it's basically 20 years old and just survived a 700+ degree torching.

Anyway, the question is, why the hell did it have to be so hot? And definitely, there's absolutely no way at all that I would have been able to remove them without his help.

What do you guys think?

[Ganreizu]

I think gunpei yokoi went too far in his philosophy of making things so easy that children could use things. :[ So far that not even adults could fix things that children break. :p