The Hair Dryer Monitor Fix

[Johnny] had a monitor that he was particularly fond of. The whole monitor appeared dead, and he decided to open it up and find out what could be wrong. He wound up fixing it — sort of — using a hairdryer. While we think his explanation of the problem is unlikely, we hate to armchair quarterback, and we applaud that he opened it up and got it working.

When something is dead, it is always a good idea to check the power and power supply, but that didn't pan out in this case. In fact, the power supply board inside had what looked like reasonable voltage values throughout. The problem had to be something more subtle.

There are a pair of low dropout regulators on the interface board, and [Johnny] suspected that one of them had gone bad. We didn't fully understand his paragraph about LDOs getting old and not being able to be re-enabled with the quiescent current if the component isn't hot enough. On the other hand, heating the components up with a hairdryer seemed to fix them. We suspect it may just be a failing solder joint, but regardless of the explanation, it works.

Apparently, the problem occasionally occurs again, and heating the spot on the case next to the regulator fixes it. Without seeing it firsthand, it is hard to be sure what's going on, but we are still going to bet on a finicky solder joint. If you want to argue for or against either hypothesis, we are sure there will be plenty of discussion in the comments.

There was a time when it was easy to work on consumer gear and it was relatively easy to get the schematics. These days everything is tiny, hard to replace if you can find the replacements, and service documentation is rare. But you can still get lucky sometimes. You just have to try.

We’ve noticed a trend of hair care products sneaking into repairs. Sometimes repairs can seem mysterious, like an infamous case of less being more.