How to test my amp's potentiometer?

Question

I was told that my amp needed a new volume pot when I bought it (I took it anyways as I was getting it for a deal with a bass) and currently I have almost no sound unless if all the knobs are turned up all the way (this is a 130W amp, too. Peavey TNT 130).

So, how can I test to see which volume pot is the problem? I have a multimeter, but how do I figure out what the 'normal' reading should be?

The volume pots are 50K linear potentiometer with pull switches... so would I test it with it pushed in or out? Or both?

Also what do I put the multimeter on? There are many options from 200m-600 VDC, to VAC and OHMS 2000K-200... I really don't know what any of those mean, so give a suggestion of what setting I should put it on please.

I'd really like to confirm that it is the pot that is the problem before taking it to a shop. Thanks.

Answer 1

To test the POT, set the multi-meter to OHMS [in the position including the 50K range]; i.e. 10K-50k.



There should be three leads on the POT where wires connect to. Turn the amp off and Place the leads of your multi-meter (the black and red wires) on any two leads of your POT. One measurement should read ~50K, the other should read some number in between. With the amp still turned off, adjust the knob the pot is connected to; i.e. the volume knob. Place the multi-meter leads back on the two POT leads where you measured less than 50K.



If no measurement from any two leads on the POT equals around 50K the POT is brook. Also, if you keep turning the POTs knob and the lesser measurement never changes, the pot is broken also.



Go to your local Fryes or radio shack to buy another POT with the same part number or model type.

Answer 2

First, is the Volume pot. the problem? If you do not even know that you use the OHMS function on the multimeter to check the pot., you are in real trouble.



I am not trying to make you feel ignorant. I am assuming that you have some electrical background? Why else would you have a multimeter?



Do you have any friends that can help you out or your dad? I think you are in over your head, but I will try to help.



To check out the pot. that is 50k, your meter needs to be on a scale that is in the 50k ohm range. Any two of the three wires that are connected to the pot. you want to test have to be disconnected. [It does not mater which two.] This the only way to test it. [some soldering experience required]



The two outboard terminals on the pot. should be tested first.If you get an ohm reading even close to 50k ,you are ok.



The next test is the middle terminal of the pot. It is called the WIPER, it is connected to the shaft inside of the pot.. Turning the shaft, swings the WIPER between the other two terminals.



To test the WIPER, connect one of the meter leads to either outboard terminal.[ Does not matter which outboard terminal you use or which test lead you use.]



Connect the other meter test lead to the center [WIPER] terminal.



Turn on the meter and slowly rotate the shaft. You should see a gradual increase or decrease in the meter reading. If the reading is smooth and does't flicker, the pot. is ok. You should use an anolog

meter not a digital meter.



Best of luck. You can e-mail me through Answers.

Answer 3

you will desire to nicely known what sign levels you're measuring/making use of as though small you are able to pick an op amp interior the circuit and if great alerts then some potential of dropping down the voltage to a usable point it ought to get extra complicated than in basic terms a pot/ variable resistor