About a week ago there was a lightning strike near my house. Both my TV and my DVD recorder went out. The surge must have come through the cable, because none of the other stuff was hurt that was connected to the TV. I junked the TV, but have kept the recorder. Last night I pulled it apart because I was told to check the fuse. I found one fuse near the power cord, but that looked fine.
Would it be possible to fix this thing? Could I do it myself, I have a multimeter, but only understand the volts part of it, and even that not very well. Are there other fuses that might have blown, I looked and didn’t see any, but the part where the cable comes in is in a box. What else can I look for, or is it a total loss?
I’ve figured that since it’s already gone I can’t screw things up any worse so maybe I can learn something.
Don’t even bother. If it’s nothing obvious like a fuse or an obviously fried component, you’ll never get it fixed unless you are very well grounded (ha!) in electrical theory, or have access to the service manual for the unit. Even I most likely wouldn’t bother with it, if that gives you any idea of the effort vs. reward curve we’re talking about here.
That’s possibly the only one. There might be a few microfuses on a board someplace. They typically look like this, or they may be small surface-mount devices like this. The latter will be MUCH more difficult to replace if you have no prior experience with SMDs. Other than that, look closely for any obviously burnt or otherwise damaged components. Bulging electrolytic capacitors indicates the part was overheated, turning some of the electrolyte to steam, for instance.
An old joke in electronics is that a transistor is the world’s fastest fuse and that a $3.00 transistor will sacrifice itself to protect a 14¢ fuse.
Given the millions of transistors that are on integrated circuits these days, odds are that at lest one of them gave its life to protect that fuse next to the power cord.
Lightning acts in very strange ways, and electronic equipment damaged by it is invariably impossible or highly inefficient to repair.
Exactly. The main problem is that fuses aren’t instant-acting devices, but lighting-induced surges have VERY fast rise and fall times and short durations on the order of a millisecond or so. You can get a massive overvoltage across a PN junction somewhere and POOF. That’s all it takes.
