Basic troubleshooting theory

1. Are there multimeter that can check capacitance
2. Does the capacitor need to be removed from the circuit to be tested?

3. Do resistors always need to be removed from a circuit to test the resistance value or does it have to do with wether the resistor is wire in series vs parallell?

yes there are  DMM's that measure capacitance.  I have 2 dmm. One  measures/ tests diodes, capacitors, resistors, VDC, VAC, etc, etc, etc.  the other is an LCR dmm and measures inductance, capacitance, and resistance.

An ESR meter is probably more important than a CAPACITANCE meter in the "troubleshooting" And YES, most of the time you will need to remove the capacitor from the circuit (often lifting "one leg" will be easier)

You probably don't know what "ESR" is... read about it- trust me- huge in the repair/troubleshooting department!

DC "resistance" Resistance **CAN** be tested "IN" circuit but the results are not to be **ALWAYS** trusted

e.g.  I suspect a certain resistor...I leave it in circuit (i.e. soldered in both sides) I measure with my meter... it says 478K and holds pretty stable (no slowly climbing or falling) I read the "COLOR CODES" and see that it is a 470K ohm resistor... I would think to myself... "It's probably okay with 80-90% certainty. I would (as a repair tech) leave that area/component and search elsewhere for the problem...

On the other hand, let's say the same resistor measured (again in circuit) 290K ohms... My first thought would be "it's in parallel with something" Because, very UNUSUAL for resistors to go  DOWN in resistance (not impossible BTW) So again, I would look elsewhere.

On the 3rd hand, same resistor, measures 1.8 Mega ohm and slowly climbing... My first thought if the resistor doesn't "look" visibly  "burnt" would be that there is residue DC voltage on the circuit... I would switch over to DC and measure/Discharge any **nearby** (could be anywhere really) Caps to eliminate the DC (which will/can distort OHMs measuring equipment.)

On the last hand... same story, resistor reads 1 something Meg or anything **"HIGH"** NO DC or VERY little I would then pull the resistor from the circuit and test it. **"HIGH"** is subjective... you gotta play this idea by ear and feel for the circuit...

if you're repairing or troubleshooting electronics, i'd recommend you pick up a copy of "how to diagnose and fix everything electronic" by michael jay geier. It's a great start for anyone trying to fix electronics. It has in depth info about why components break down and how likely it is that they are defective, lots of info about how to use test equipment and what comment faults are in common circuits.

Eventhough i've been working with audio electronics for about 10 years and working as a repair engineer for a backline company for about a year and a half, i found it usefull nonetheless. it's a good book especially for a beginner. And it covers all your questions very indepth.

greetings,

Thomas

thankx guys.

I need to add: With an ESR meter you often(if not always) do NOT need to lift the capacitor... you can test it right in circuit.

Basic troubleshooting - Use all your senses. Sight, Touch, Hearing, Smell

Sight - does anything look out of the ordinary? Burnt component, disconnected/loose wires, bulging capacitor tops, etc?
Touch - is any component getting hot, too hot, or very hot that is not supposed to? ... - this may not be advisable for high voltage circuits, etc.
Hearing - anything buzzing, rattling, vibrating, loose?
Smell - does it smell burnt? Where is the smell coming from? Is some liquid/paste leaking from somewhere (ex: electrolytic caps)

Resistors usually do not fail... unless there was a short somewhere and then it got burnt. Easy to spot.
Caps usually do not fail... unless it's very old, or exceeded it's voltage rating, or you see gunk leaking out of it's base or top.

Active components usually are the culprit... ICs, transistors, etc.  ICs are easy to replace, provided they're in sockets.

Try to determine what area of the equipment is not working. Then concentrate on that area.

If it's an audio circuit, a signal generator and scope is useful. You can probe and follow the signal... and see where the signal suddenly dropped, disappeared or went distorted.  If the input to an IC chip looks good, and the output looks bad or there is no output, then most probably it's a faulty IC.

Think logically. If the equipment is dead, before you think of disassembling it, see if the equipment is plugged in! If it's plugged in, and everything is still dead, follow the voltage... outlet, inlet, fuse, switch, transformer/psu and go from there.