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TV componant Testing With a DMM

M

Mike

Jan 1, 1970
0
Hello,

Can a tech reasonably test and possibily repair a tv and or monitor with
just a DMM?
I realize that a scope would be a great aid in the repair process...

Mike
 
N

NSM

Jan 1, 1970
0
| Hello,
|
| Can a tech reasonably test and possibily repair a tv and or monitor with
| just a DMM?
| I realize that a scope would be a great aid in the repair process...

In the days of tubes, many did it with a multimeter. I still prefer a VTVM
to a DMM, but a scope is a real time saver and for some reason they are
selling for very small $$$ on eBay right now. You really need a lot of
experience to use a DMM only.

N
 
J

James Sweet

Jan 1, 1970
0
Mike said:
Hello,

Can a tech reasonably test and possibily repair a tv and or monitor with
just a DMM?
I realize that a scope would be a great aid in the repair process...

Mike

Yes, I almost never drag out the scope for TV/monitor repairs.
 
S

Sam Goldwasser

Jan 1, 1970
0
NSM said:
| Hello,
|
| Can a tech reasonably test and possibily repair a tv and or monitor with
| just a DMM?
| I realize that a scope would be a great aid in the repair process...

In the days of tubes, many did it with a multimeter. I still prefer a VTVM
to a DMM, but a scope is a real time saver and for some reason they are
selling for very small $$$ on eBay right now. You really need a lot of
experience to use a DMM only.

A scope helps and may be essential in many cases but it's often possible.

See the info at the site below.

--- sam | Sci.Electronics.Repair FAQ Mirror: http://repairfaq.ece.drexel.edu/
Repair | Main Table of Contents: http://repairfaq.ece.drexel.edu/REPAIR/
+Lasers | Sam's Laser FAQ: http://repairfaq.ece.drexel.edu/sam/lasersam.htm
| Mirror Sites: http://repairfaq.ece.drexel.edu/REPAIR/F_mirror.html

Note: These links are hopefully temporary until we can sort out the excessive
traffic on Repairfaq.org.

Important: Anything sent to the email address in the message header is ignored.
To contact me, please use the Feedback Form in the FAQs.
 
O

Ol' Duffer

Jan 1, 1970
0
Can a tech reasonably test and possibily repair a tv and or monitor with
just a DMM?

In many cases, yes. You can check voltages, resistor values,
and semiconductor junctions. Most DMM's don't have a capacitor
test, but you can measure AC ripple as a rough indicator.

In my experience, maybe something like a quarter will yield to
visual inspection (symptoms, burnt parts, cracked solder joints
and such), and the majority of the rest need measurements you
can do with a DMM. Maybe 5% will cause me to break out the
silly-scope.

And, of course, knowledge is the most valuable tool.
 
N

NSM

Jan 1, 1970
0
|
| > | > | Hello,
| > |
| > | Can a tech reasonably test and possibily repair a tv and or monitor
with
| > | just a DMM?
| > | I realize that a scope would be a great aid in the repair process...
| >
| > In the days of tubes, many did it with a multimeter. I still prefer a
VTVM
| > to a DMM, but a scope is a real time saver and for some reason they are
| > selling for very small $$$ on eBay right now. You really need a lot of
| > experience to use a DMM only.
|
| A scope helps and may be essential in many cases but it's often possible.

If you aren't experienced, figuring out each stage of testing will go from a
few seconds up to a few hours! It's a slow way to fix something unless you
have the knowledge and experience. After quite a few years you get to the
point where you can make very educated guesses from the symptoms alone.

I went to visit a friend of mine once who was an expert on hydraulics but a
novice on electronics. He told me he had a 5 tube set he had been trying to
fix with a multimeter with no success. I listened to it, looked at the tubes
and borrowed a screwdriver and shorted each main filter cap section to
ground. I found one that had no 'splat' and borrowed a pair of pliers. I
shorted out the power resistor that fed that section from the one above and
the radio started to play. 30 seconds and no meter. At least HE was
impressed!

N
 
H

Hotspur

Jan 1, 1970
0
Hello,

Can a tech reasonably test and possibily repair a tv and or monitor with
just a DMM?
I realize that a scope would be a great aid in the repair process...

Mike
If it's a one off give it a go,if you want to try more get a scope
with a componant tester.I know I'm a bit old school but I did my
qualifications in the Royal Navy,5 years of slog as an apprentice{try
repairing a radar set in a force 9! swing those lamps!]
Following traces and watching waveforms can show up ripple faults that
normaly you would not find.
As for intermittent faults[the worst] you would be very lucky with a
DMM to find them.
I used a scope,frequency counter,waveform generator,colour test
gen.etc. In short for a once only outlay it was all there at hand on
the bench.Depends on how many you want to do.Gear is cheap to buy now.
Think I'm glad I'm retired I don't think I could keep up with modern
electronics changing as fast they are.Good luck
 
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