Over the holidays my old Nintendo Game Boy (the original DMG-01 model) has resurfaced. It works, but the display had a bunch of vertical lines near the left and right border that stay blank. Apparently a common problem with these older Game Boys and the solution is to apply heat to the connector foil upper side to resolder the contacts hidden underneath. There’s lots of tutorials and videos on the subject so I won’t go into much detail here.
Just one thing: The easiest way is to use a soldering iron (the foil is pretty heat resistant, it has to be soldered during production after all) and move it along the top at the affected locations. Which I tried at first and it kind of works but takes ages. Some columns reappear, others disappear, reappeared columns disappear again… In someone’s comment I read that they needed over five minutes until it was fully fixed!
So… simply apply a small drop of solder to the tip. That’s what you do for better heat transfer in normal soldering and of course it also works here (since the foil connector back doesn’t take solder this doesn’t make a mess or anything). That way, the missing columns reappeared practically instantly at the touch of the solder iron and stayed fixed. Temperature setting was 250°C, more than sufficient for the task.
This particular Game Boy always had issues with the speaker stopping to work but we never had it replaced, I think because the problem was intermittent. After locating the bad solder joint on the connector and reheating it this problem was also fixed. Basically this almost 28 year old device is now in better working condition than it ever was.