Teaching myself

[rabler]

Learn Ohm's law

V = I * R
P = I * V
Those two cover a quite a bit of electronics.

 

[markba633csi]

MOVs are a protection device like a fuse in reverse. Normally they are open (very high resistance)
Really high voltage surges can damage them, as you found out
They sacrifice themselves to protect the circuit
Metal Oxide Varistor

 

[ltlvt]

MOVs are a protection device like a fuse in reverse. Normally they are open (very high resistance)
Really high voltage surges can damage them, as you found out
They sacrifice themselves to protect the circuit
Metal Oxide Varistor

Then should I consider the one that shows continuity is bad and go ahead and replace it? I have plenty new MOV's so it just means remove and replace. Also I have a few resistors that show open . Should I consider an open resistor bad? Thanks for the reply.

 

[Just for fun]

What is the value of the resistor? If it doesn't fall within the tolerance it's bad.

 

[mac1911]

Credit to you for jumping into this. It is an open ended thing, as reading schematics means knowing what all the symbols represent, and what those things do. Those symbols are not completely standardized so different times and different countries may use different symbols, etc. Doesn't mean you can't make use of elementary knowledge, a multimeter, and basic safety precautions, to do useful work in understanding and fixing electronics.

And then pray the diagrams are correct.

 

[rabler]

Then should I consider the one that shows continuity is bad and go ahead and replace it? I have plenty new MOV's so it just means remove and replace. Also I have a few resistors that show open . Should I consider an open resistor bad? Thanks for the reply.

Yes, shorted MOVs have sacrificed themselves to hopefully protect the circuit. It'll need to be replaced. Relatively common issue when across AC line input.

Open resistors are also bad. You can decode the color bands to decipher what value it should be. Open would usually mean they have been overloaded and burnt out like a fuse. Fairly rare for that to happen in a circuit normally. Would mean that it's power rating was exceeded significantly. Fairly rare, so I would consider how that could happen, such as 240V to a 120V device.

 

[markba633csi]

Ohm's law and reading resistor color codes- both valuable skills
A very high value resistor may appear/measure open- many meters can only go so high- a few megohms

 

[rabler]

reading resistor color codes- both valuable skills

BBROYGBVGW = Black Brown Red Orange Yellow Green Blue Violet Gray White = 0 1 2 3 4 5 6 7 8 9
There's a common nemonic used to remember that, starts out Bad Boys ... but probably not suitable for a PG site.

 

[mmcmdl]

I am learning a lot as I go and surely need new glasses and brighter lights.

You and me BOTH !

I thought the thread title read ........Touching myself !

 

[Just for fun]

BBROYGBVGW = Black Brown Red Orange Yellow Green Blue Violet Gray White = 0 1 2 3 4 5 6 7 8 9
There's a common nemonic used to remember that, starts out Bad Boys ... but probably not suitable for a PG site.

......but Violet Goes Willingly