I didn't expect you to want to go deeper into the board for repair.

I was suggesting that it was just something to check as if was acting like a fuse. Just undo one end and check it. If you do replace one, first mark on the circuit board which way the band is and put it back that way.

When checking diodes with an ohm meter it is fine to so by comparing for the dramatic difference in resistance. I do not recommend using an ohm meter to identify the polarity of them. You have to know the polarity direction of the battery current from the meter to do it correctly. You just need to know which lead is really the cathode or anode. Is it Red or black? Your manual might tell you if it has a diode function built in.

As far as the variances between one to another, there are manufacturing tolerances within the same component.

I learned these tidbits from using unmarked diodes from Radio Shack in my early learning experience of trying to build one of their early clock kits and that was a really long time ago!

I do not trust the quality of their stuff but in a pinch I still go there. The kit was furnished with unmarked ones in it. They must have swept up the manufactures production floor to buy those!

My meter got me backwards, so consequently, it didn’t work right away. I should have tossed them but I thought I knew enough, besides they were in the kit.

Sometimes you never really know when you are enrolled, to learn a lesson!

I have learned to take pictures and make good notes. Try to only remove one thing at a time. Study all the solder connections and traces before jumping in because a lot of the time, that is what is bad.

Try to follow the supply voltage, with your voltmeter, to where it goes and where it might be stopping.

I'm currently working on an old (30 years) fish finder. I'm replacing all the electrolytic capacitors of which there are approximately fifty of dispersed on three boards. They go bad with age and are a cheap first step attempt to fix.

This is a color screen model, like a computer monitor, that if you tried to replace it would cost in excess of $3,000. I have as much chance of fixing this as catching fish because I know about as much about fish. This is my neighbor’s project again. He would like to sell his pasted Dad’s boat and the fish finder would make it a really good deal.

The unit got where it would not turn on if it was too cold outside. Would you know, it quit all together now, when he wants to sell the boat this summer.



If you guess it, I'm still learning too. It is because I like learning new things too! So if you are doing the same thing, this is a clue of what it can lead to. Electronic tinkering is like my final frontier. I have taken a couple semesters of electronics in junior college. You get a bunch of engineering math and related garbage to frustrate you right off the get go.

I have learned more by reading about what a device is there to do and then studying the symptoms. Then, I think a lot! Define the area that will lead to the most likely culprit. Still, I haven’t been able to fix everything but the average wins, are creeping up.

Besides, the electronic things are throw away. I get to practice and the parts are for nothing or are usually cheap. You can buy three or four capacitors one reasonable price or get 10 for the same price! Thousands sell for the price of dirt!
Makes sense but wish it happened to cars but we all know that will never happen because there is not enough competition.

You can download a device lookup program from NTE will help you identify components unless they are proprietary components. Some stuff is locked up in an IC chip and demands replacement anyway. I undo them. I buy a socket (10 for a $1.50) to plug the next one into. No heat evolved to the next chip. It’s a safer switch out. It is heat that can weaken a chip for future failure. That may have lead to an early failure in your device. A chip for the chime box in our (91) cars, is fifty cents!

Digi-key and Mouser are other electronic information sources for parts that I use.

Find a local electronic parts house. They are good for books and other advice. They may know nerds that may be willing to help you. Networking and bartering. It’s was a way in the past as I grew up and now it is the future way for sure. Hourly rates are killers for a little of nothing done.

Past some simple components you are going to find that most of the unit is an IC. You’ll have to find what is not responding to power or not getting it. It will be a challenging puzzle but not impossible by any means.

Just a matter of the “meanness” you have!
Phil