Reddit reviews CRAFTSMAN 3482141 8 Function Digital Multimeter
We found 7 Reddit comments about CRAFTSMAN 3482141 8 Function Digital Multimeter. Here are the top ones, ranked by their Reddit score.
Measures up to 600 volts alternating current and 10A alternating current for electrical installation home appliance repairsMeasures up to 600 volts direct current and 10A direct current for auto marine and electronic installations or repairsAudible tone sounds below 30 ohms to check proper wiring and shortsResistance is up to 2 megaohm for household and auto electrical wiring testing and repairDiode test for electronic and electrical testing
Craftsman 34-82141 Digital Multimeter with 8 Functions and 20 Ranges https://www.amazon.com/dp/B000X5TSUA/ref=cm_sw_r_cp_apa_hyyDybCDCEG49
Under $20. Does everything you need it to. I install elevators. My old mechanic had this meter as a backup. It got the job done.
It's not so much the barrel jack as making sure you're delivering the right voltage; too much and you could fry your servo. You can use a multimeter (something like this) to test the voltage coming from your batteries and compare with the needs of your servo.
What are you using to provide a signal to the servo? In my case I'm using an Arduino
Craftsman 34-82141 Digital Multimeter with 8 Functions and 20 Ranges https://www.amazon.com/dp/B000X5TSUA/ref=cm_sw_r_cp_api_i_U2YPDbRKTTDA3
Make and model of the laptop will help immensely. Does it have a removable battery? The first thing I would do is remove the battery and let it sit for 20 minutes to a half hour or so. If there was a power surge this will let any capacitors settle back to zero.
Second, I would examine your power adapter for any frayed wires or kinks. Laptops get moved around a lot so it's easy to break the end that plugs into the computer or kink the wire near the transformer (the brick). Also, if it's a two piece cord make sure to unplug both pieces and inspect the connections to make sure the metal connectors are clean and without corrosion or breaks.
Once you've made sure everything looks ok you can plug your battery back in (if it's even removable in the first place), plug the power adapter back in and try a different outlet just to make sure there's not an issue with the power at that receptacle. Press the power button and see what happens. If you're still not getting any indication of power whatsoever you're looking at one of two things:
Testing your power adapter is easy. If you have a multi meter or volt meter just google how to test a DC power supply. If you don't have one, even a cheap one like this would likely serve you well. If you don't want to do it yourself or don't trust yourself you can always take it to an electronics repair shop. It takes less than a minute for them to tell you whether or not your adapter is functioning and if it's outputting the correct voltage.
If your power adapter tests ok, all hope isn't lost. Many times the power connector in laptops also loosen over time simply because we tend to move them around while they're plugged in. If you plug in the power adapter and the connection feels loose or wobbly, you might have an internal solder connection that has broken. This is substantially more expensive to fix, but many local electronics or PC shops will take on repairs like this. I've done several myself.
If you need any more info, let me know. If you're experienced with electronics and I've spouted off a bunch of stuff you already knew, sorry :).
OP for $10 it's well worth the price. I've owned this one for over 8 years
Amazon Canada, almost double the price:
https://www.amazon.ca/Craftsman-34-82141-Digital-Multimeter-Functions/dp/B000X5TSUA/ref=sr_1_1?ie=UTF8&qid=1484172418&sr=8-1&keywords=Craftsman+34-82141