r/Flipping • u/Alarmed-Fruit5056 • 1d ago
Advanced Question What tools do I need for testing electronics?
Basically what the question says. I’m dealing mostly with small / personal / home electronics — computer accessories, cameras, beauty tools, that sort of thing. But I occasionally pick up a power tool here and there. So far I’ve been winging it, but my inventory is growing, and I’d like to be able to have more certainty over what works and what doesn’t.
I’ve done some research and it seems that I need a multimeter for batteries and power adapters, and perhaps a different tool to test actual devices? Is that correct? Any product recs and/or considerations when shopping for them are welcome.
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u/DrFrylock 1d ago edited 1d ago
A multimeter is the most flexible tool for testing. A good midrange one with autoranging is probably as much as you'll need for most things.
Others in this thread have recommended a benchtop DC power supply. Definitely useful for a variety of things, although you can't really "test" electronics with it yourself. It can be used in conjunction with, e.g., a multimeter to test things.
One thing I see a lot of electronics repair folks using these days is a capacitor tester/ESR tester. A regular multimeter will generally not give you a good answer to "is this old electrolytic capacitor still good?" Since capacitors are probably the electronic component most likely to degrade over time, and because that degradation is not always easy to see with just a visual inspection, having a tool that can test one can be useful. Little pocket models run about $75.
Beyond that, if you want to look at how signals or levels vary over time, you can use an oscilloscope. These are complex tools that vary widely in capability and features. Many electronics repair people get by without a scope, or using only a very basic scope. Unless you are designing or debugging complex electronics a basic scope may be more than you ever need, if you use one at all. You may be able to get an older scope on the secondary market for much less than you'd pay for a new one.
A digital microscope is useful for guiding detailed work and visual inspection of tiny components. This is not like a regular microscope with a glass slide, this is basically a camera with a super zoom lens that can show small details clearly. This is primarily useful if you are examining or repairing surface-mount boards. And the repair of surface mount boards requires a lot of skill and specialized equipment, beyond the above.
Similarly, a thermal camera can be used to quickly locate the source of a short circuit. You use your DC power supply to inject some voltage onto a board, and then see if there is a hot spot that emerges. Often that gives you a clue as to where a faulty component may be. Again, this is for pretty advanced repairs.
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u/Ok-Curve-3894 1d ago
"although you can't really "test" electronics with it"
The magic smoke test is a legitimate, and useful troubleshooting step.
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u/iRepTex 1d ago
I have 2 universal chargers. One for batteries (you slide the prongs over the + & - terminals) and the other for power cables (has various tips and adjustable voltage). Between those 2 I can power on most electronic things for testing.
90% or higher isopropyl alcohol for cleaning
Vinegar for removing corrosion. I flipped so many electronics that had corrosion that people didn't want to deal with and sold for cheap that I got working after a few minutes of cleaning.
Air duster or canned air.
Screw drivers with swappable tips. ifixit has a great tool kit.
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u/Zolty 1d ago
What sort of corrosion are you removing with vinegar? I’m picturing corroded battery contacts typically I neutralize that with baking soda and water.
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u/Agreeable-Fudge-7329 1d ago
It's not a bad idea to get a VARABLE SPEED Dermal or rotary tool for those really thick battery crust. Variable, because if it is at too high a speed, it will break that battery lead clean off!
It is also amazing at polishing-up those leads.
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u/IAmBrahmus Loathing Hater 12h ago
Alkaline batteries are alkaline so baking soda is just providing abrasive to the water to scrub terminals. Vinegar neutralizes it. Car batteries use battery acid so baking soda works there. Blew my mind when I learned this lol.
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u/Ok-Curve-3894 1d ago
I flip a lot of digital cameras and a universal lipo charger has been great. I used to use a bench top power supply, and that's still useful for trying to power stuff I don't have wallwarts for.
I also have an old laptop running ubuntu for securely wiping harddrives
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u/tiggs 1d ago
You honestly don't need much. A multimeter isn't a horrible idea since it's versatile, but it's not exactly hard to plug things in to an outlet or keep batteries on hand to test stuff. For the types of items you listed, you certainly don't need an entire bench of testing supplies.
For things like cameras that don't have batteries, you can order a third party charger and 1/2 batteries for like $12 for most items. Investing $12 there will add a lot more than $12 to the price you get for the item and will make it sell a lot quicker. If the item ends up not working, you can sell it for parts and the battery/charger will still add on value.
Don't worry about testing capacitors, currents, and shit like that. If something doesn't work, just sell it for parts. Don't be the guy that invests $100 of his time to repair an item that sells for $50 and end up until water when you could have just unloaded it for parts and make your money back with a slight profit.
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u/HorsieJuice 1d ago
A universal power supply, usb cables of various formats, and some av cables - to make sure it powers on and that it sends the appropriate signals.. If you need anything beyond that, sell it for parts or chuck it. If you don’t already know how to fix this stuff, it’s not going to be worth your time trying to figure it out.
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u/Zolty 1d ago
Dc power supply with all the barrels and usb connectors.
Soldering set with heat gun and flux and solder.
Electric precision screwdriver.
Heat gun.
Multimeter.
Go-gone or similar label removers.
Digital microscope that will zoom in at least 10x, one of those magnifying lights works great.
Baking soda to neutralize battery acid.
Acetone, alcohol, electronic contact cleaner, a lite synthetic lubricant.
A supply of scrapers,brushes and other label removing implements.
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u/Agreeable-Fudge-7329 1d ago edited 1d ago
Definitely a Multimeter. Doesn't have to be fancy, but you will need a quick tutorial on the main functions.
I especially use these when testing replacement batteries. I put them in photos for things like power tool batteries to show that they are still holding a charge.
I used a device that outputs variable DC voltages from 0 to 48v it has two probes (+/-) that you can apply to batter leads to bring power to the device, without having to have to have every battery under the sun, or enough of them. I got mine from an estate sale cheap, but there are more basic cheaper models that just go up to 12v that will accommodate 99% of what you will ever test.
I do keep a supply of batteries i find at estate sales, though. Weird camera and "button batteries" are going to come in handy.
I would recommend getting some rechargeable AA and AAAs for sure. It just saves money. Maybe toss in a 9V eventually.
Yes, a DC adaptor with changeable "ends" is always a good idea. Make sure the "brick" has a switch to change the voltage AND the "polarity" those rare times it's needed.
As you get good, you are going to do a lot of "improvising" and modifications of stuff to power awkward devices. You'll realize it when it happens!
If you go to a place like the Bins, start a collection of AC adaptors! Some devices will require "ends" that you simply cant eaisly buy, and having that adaptors with the perfect plug, and correct voltage, is a life saver!
Edit: if you are testing audio devices, a simple pair of computer speakers with a 3.5mm jack, and various adaptors to plug it into either 1.4" or RCA, will be a must! But if you are a regular estate sale or Bins shopper, ypu will run into these eventually. Scoop them up and add it to your toolbox!
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u/Agreeable-Fudge-7329 1d ago
Definitely a Multimeter. Doesn't have to be fancy, but you will need a quick tutorial on the main functions.
I especially use these when testing replacement batteries. I put them in photos for things like power tool batteries to show that they are still holding a charge.
I used a device that outputs variable DC voltages from 0 to 48v it has two probes (+/-) that you can apply to batter leads to bring power to the device, without having to have to have every battery under the sun, or enough of them. I got mine from an estate sale cheap, but there are more basic cheaper models that just go up to 12v that will accommodate 99% of what you will ever test.
I do keep a supply of batteries i find at estate sales, though. Weird camera and "button batteries" are going to come in handy.
I would recommend getting some rechargeable AA and AAAs for sure. It just saves money. Maybe toss in a 9V eventually.
Yes, a DC adaptor with changeable "ends" is always a good idea. Make sure the "brick" has a switch to change the voltage AND the "polarity" those rare times it's needed.
As you get good, you are going to do a lot of "improvising" and modifications of stuff to power awkward devices. You'll realize it when it happens!
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u/bradjoray3 1d ago
I mostly focus on handheld tech rather than a super wide range of stuff, but for the vast majority of handhelds that take batteries, get a bench power supply. it is like £50/$70 and you can just hook devices up to that, so you dont need to waste time charging batteries, or if the battery is dead, no charger available etc. It is a total lifesaver and worth every penny