Magic tricks? Desolder IC's from MTX PCB?

[Crazyboss]

Hi.

Anyone have a magic trick to desolder IC's from the MTX PCB without destory the IC ?

The problem is it seems like its soldered from both sides of the board. I have a quite good desolder station. But its limited success to use it on the MTX PCB.
I have tried different ways like:

Flux the component side and apply flux and solder to the solder side.

I tried tempertures like 370-375c at the desolder station.

It seems like the most easy way is to cut the IC and then desolder the pins one by one. Its also the way to do it when replacing 4116s at the ColecoVision.

Some youtubers uses hotair, but dont now how well it works on mtx boards.

Any magic trick?

[stephen_usher]

I use a Hakko FR-301 on the solder side and then hot air on the top to melt the final amounts whilst using tweezers to gently pull the chip up and out of the holes when the solder is melted. All this helped by lots of flux.

[1024MAK]

For me it depends. If the old chip is toasted (dead) or a prime suspect, unless it’s a hard to get or expensive type, I cut the legs and desolder the individual legs.

Otherwise it depends on how awkward it is. For large or awkward chips, I use hot air. I use an electric paint stripping ‘gun’, every now and again poking the pins of the chip with a screwdriver to see it will fall out of the board. You do have to be careful with this method thought. Otherwise you can damage the board, or other items fall out of the board!

Otherwise I either use a desoldering station (which uses an electric vacuum pump) or I use an Antex TCS 50W iron with a large chisel bit and a normal hand solder sucker.

Occasionally I prop up the board vertically and use a soldering iron on the other side at the same time as the desoldering station.

When using a normal iron, it is important to understand that it’s not just the bit temperature, but also the physical amount of heat that it can hold and then transfer to the solder joint. Hence larger bits that are tinned work better.

The things that are a real pain the the arse, are square pin items like connectors where the size of the pin only just fits in the PCB hole. They are very hard to get out without destroying the connector.

Mark