General Troubleshooting Advice

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e57

e57

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Location
San Francisco, CA
Posted this somewhere else and figured it was a good idea....

There aught to be a sticky with general troubleshooting advice.

But heres mine:

  1. Draw out a Line Diagram or Schematic to help visualize the circuit. And up-date it as you go along.
  2. Always test against known sources - test the end of an extension cord H-N-G to grounded plumbing will help confirm that it is a "known source" - then you can take this extension cord (one phase, a neutral and a ground) with 3 of 4/5 known sources to what it is you need to troubleshoot.
  3. Know your equipment... The differences of operation of both a DMM, and say a wiggy can be misleading if you don't know how to interpret them.
  4. Always follow the rules when disconnecting any conductors... Disconnect ALL ungrounded conductors first, then grounded, and if needed grounding.... IN THAT ORDER!
  5. If it worked before - it is not a wiring pathway problem. If it never worked before it just might be a wiring pathway problem.
  6. "Divide and Conquer" divide the circuit into operational and non-operational parts - then further divide the non-operational part.
  7. Follow a 'short' away from the source to the ends of the circuit, follow an 'open' from the ends of the circuit to the source.
  8. Use your head, not your heart - follow safe working procedures when dealing with energized conductors.
 
I think #5 is one of the most important things. I don't know how many times I have followed other trouble shooters who did not understand this and they tried to fix the issue by rewiring the circuit...making even harder to fix.
 
In the electrical lab we have faced some of this troubles and haven't any idea what to do.Thanks for your advices.its very helpful for us.:)
 
zog said:
1. Learn electrical theory, not just Ohms law, all of it.
2. Apply it
Click to expand...
I'll buy that.... Problem - most people are weak on theory... But it is one of the keys to figuring stuff out...

Over-Simplified:
You need a complete circuit path for any device, equipment or appliance to work.

If it needs a hot and neutral to work - look for the hot and neutral*...

Confirm the circuit path before condemning the device, equipment or appliance.

(*Something that can not be done with say an inductive tester...)
 
Never assume it was wired correctly and to any Codes in the first place. Just because 'it works' doesn't mean it was right.
 
#6 is also valid, I will have techs beating their heads against the wall trying to find a shorted ballast in a long run lights, breaking down every fixture they come to, when they can eliminate 50% of the lights by just cutting the circuit in half.
 
And if there is a circuit board issue, toss it in the trash. don't waste your time on anything past the little bitty fuse...


Boy am I going to get lamblasted for this comment.:D
 
MikeyinLA said:
Take the problem from the reporting party with a grain of salt, they exaggerate, or worse..
Click to expand...

Most of the time they don't even know how to describe it... Sometimes you need to do a little Poirot. (An Agatha Christie Character)

Was it a 'hum', or a 'buzz', or a 'hiss'? Did they get dimmer, or were they dim, then got brighter? Smoke or a smell? Flames or sparks?

And Yes - a few flat out LIE! And it is usually something they did that was the problem.
 
480sparky said:
Never assume it was wired correctly and to any Codes in the first place. Just because 'it works' doesn't mean it was right.
Click to expand...

If it used to work and now it does not work it is not the time to start changing how it was wired.

Once you get it working again you can start looking into code compliance.
 
1. Listen to everything on site people tell you, never believe any of it, find out for yourself
2. Always test your test equipment.
3. Never get excited and think you have solved the issue at hand till you have.
4. Try to hold blame for poor quality to yourself, temper your remarks to customers (many of the problems I solve for customers were installed by EC's I work for).
5. If it seem unusual or improbable it most likely is, keep looking.
6. This ain't magic, a man/woman made it, installed it a man/woman can fix it.
7. Driving ground rods solves nothing.
8. Voo Doo grounding does nothing to solve the issue, in some circumstances it may mask the problem, but it still exist.
9. Blaming harmonics or grounding never resolves the issue, find out the problem.
 
brian john said:
1. Listen to everything on site people tell you, never believe any of it, find out for yourself
2. Always test your test equipment.
3. Never get excited and think you have solved the issue at hand till you have.
4. Try to hold blame for poor quality to yourself, temper your remarks to customers (many of the problems I solve for customers were installed by EC's I work for).
5. If it seem unusual or improbable it most likely is, keep looking.
6. This ain't magic, a man/woman made it, installed it a man/woman can fix it.
7. Driving ground rods solves nothing.
8. Voo Doo grounding does nothing to solve the issue, in some circumstances it may mask the problem, but it still exist.
9. Blaming harmonics or grounding never resolves the issue, find out the problem.
Click to expand...
I'm gonna agree 100% with 1 ~ 6 with special enphisis on 1 ~ 4....

7 ~ 9 sound like you have had a recent issue(s) with some sort of AV guy... :roll:
 
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