The problem with applying heat to the opposite side of the wire that the solder is on, is heat transfer. You will have a very tiny point contact between the iron and the wire to heat the wire. The result is a lot of heat travels up the wire, damaging insulation etc upwire before the joint location ever gets hot enough.
I found the most effect way is to make sure the contact is clean and rosin fluxed and use a solder ball on the end of the iron (make sure the iron tip is clean too and maintain the tip in a ‘tinned’ state. The ball ensures maximum heat transfer when it makes contact with the wire. This allows you to ramp the temp of the joint up rapidly and complete the job before the heat travels up the wires and does damage further up. Also use a good iron like Metcal if you have one.
On that ribbon cable, your biggest problem is not going to be soldering the new on on.. it will be removing the old. This is generally done with a very specialized hot air gun (don’t try it with your run of the mill hot air gun).
Have we really gotten to the point of a disposable society in which you chuck out your electronics after 1 year or use or less because the cost of labor is too high to repair?
Yes.. need you ask. These days, if a seal on a rack and pinion steering rack goes bad, you replace the whole rack. If a distributor gear gets a little worn, you replace the entire distributor (newest cars don’t have distributors though)
Some older timers who use to build Heathkit TV’s, Ham Radio’s etc could solder it for you.
Nope.. don’t. The joints are much finer than these people have ever done. You want one of the assemblers that works currently at companies like Sony, Qualcomm, Cubic. They work with surface mount, the problem is that they don’t own their own tools and the tools are specialized.
