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 Post subject: Cheap Component Tester
PostPosted: Jan Sun 28, 2018 4:45 am 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 500
Location: Effingham, IL
You can't beat the price and seems handy to have around.https://www.youtube.com/watch?v=7Br3L1B80ow
Sorry if it has been discussed before.


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 Post subject: Re: Cheap Component Tester
PostPosted: Jan Sun 28, 2018 6:19 am 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 17772
Location: Albuquerque, NM 87123
I haven't used one but a guy in my radio club has one and likes it. There is a Youtube video made by Shango006 where he demonstrates one; it's supposedly really good for determining gain of germanium transistors. You can get one with a clear case for about $15 on eBay.


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 Post subject: Re: Cheap Component Tester
PostPosted: Jan Sun 28, 2018 3:10 pm 
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Joined: Jan Mon 28, 2013 9:35 pm
Posts: 1104
Location: Santa Rosa, CA
These have been discussed here before. Wonderful bench tools!
I've bought two of the M328 version and use them all the time.
Cases for these are easy to make. The last one was a piece of
scrap walnut, 3/4" thick, which was hollowed out for the board and battery.
I used a piece of clear acrylic plastic on the top and bottom of the
wood. Looks nice, rugged and protects the PC board.
Steve

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 Post subject: Re: Cheap Component Tester
PostPosted: Jan Sun 28, 2018 3:34 pm 
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Joined: Jun Fri 19, 2009 6:34 pm
Posts: 7959
Location: Long Island
You get what you pay for. It's basically a knock-off of a class project done by a German microprocessor training program to show "it can be done." While it can identify the leads of unmarked semiconductors and diodes, it applies AC voltages which may be sufficient to damage really sensitive components like the sampling diodes used in some HP and Tek instruments. So you only want to use it on common types of silicon and germanium semiconductors, nothing particularly rare or exotic. On passive components it uses a simple voltage-over-time measurement circuit which is okay for resistors but can be way off for certain kinds of capacitors.

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 Post subject: Re: Cheap Component Tester
PostPosted: Jan Sun 28, 2018 4:08 pm 
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Joined: Jan Mon 28, 2013 9:35 pm
Posts: 1104
Location: Santa Rosa, CA
Well Chris, every instrument has its limitations. That goes for the stuff
that costs $10's of kilobucks too. I should know, I designed and used many
of them.

I've used these muti-testers for quite a while now and cannot think
of ANY newer tool that is more flexable and useful for an absurdly
low price. IMO, every bench should have one of these.
Steve

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'cell phones and the internet are tools, not a lifestyle'


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 Post subject: Re: Cheap Component Tester
PostPosted: Jan Sun 28, 2018 4:40 pm 
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Joined: Jun Fri 19, 2009 6:34 pm
Posts: 7959
Location: Long Island
I certainly agree with you that every instrument has limitations and any good technician or engineer knows what they are. In the hands of somebody who knows the limits of one of these devices, it can be quite a convenience. And yes it is a lot of bang for the buck.

Problem is, some of the people reading these forums are hobbyists with no formal technical or engineering training. They buy a device like this because it is cheap, it's new, and it's on u-tube so it should accurate to three decimal places on everything they test--right? Then when they can't figure out why things don't work out as they should, we get to explain what reality is. 30-40 year old HP bench LCR meters still often go for thousands of dollars on eBay; even old Sencore LCR meters designed for monitor repair are worth hundreds. And those don't even attempt to test semiconductors. So why would people spend that kind of money when they could get a new "one-chip wonder" for $15 or $20 bucks if it does even more than the old clunkers do? Might it have something to do with limitations?

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 Post subject: Re: Cheap Component Tester
PostPosted: Jan Mon 29, 2018 3:05 am 
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User avatar

Joined: Nov Mon 02, 2009 7:01 am
Posts: 3044
Location: Lincoln City, OR
Greetings to the Forum:

Chris108 writes:

Quote:
So why would people spend that kind of money when they could get a new "one-chip wonder" for $15 or $20 bucks if it does even more than the old clunkers do? Might it have something to do with limitations?


I wonder if it might have something to do with the onward march of technology? I have a Rigol spectrum analyzer that I paid just a bit more than a grand for. I also have a couple of 141T's by HP. These cost in the neighborhood of $75K when new. Within its frequency range, the Rigol does everything the 141T does and more and it fits nicely on my bench.

My $20 whiz-bang gadget from China displays capacity accurately as well as ESR. Would it work for caps in the small pF range? Probably not.... but neither would any of the DMM type capacitance testers that cost a lot more. I trust my little gadget.... and I have never been steered wrong yet.

I have a Tektronix 130 LC meter, but it mostly sits on a shelf and gathers dust.

Regards,

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Jim T.
KB6GM


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 Post subject: Re: Cheap Component Tester
PostPosted: Jan Mon 29, 2018 3:28 pm 
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Joined: Jan Mon 28, 2013 9:35 pm
Posts: 1104
Location: Santa Rosa, CA
Jim,
You can measure caps in the low pF range with your cheap-o tester
easily. Select a good quality (1%, 500v or so) mica cap that is
about 50 to 100 pF. Get an accurate measurement on it with your
Tek 130 and label it. By putting a small value cap in parallel you simply
measure the two and subtract your 'standard'. Used mine the other day
to sort though a pile of RFC's. Found one with an internal short.

I've been looking for a Tek 130 for years. Nice instrument! Found an
equivalent made by Rhode and Schwarz a while ago. Built like a tank
and works great!.

Haven't had a chance to use a Rigol scope or SA yet but people that
have them seem to be impressed. Have a wide selection of HP and Tek
SA's here so doubt I'll ever buy another.
Steve

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'cell phones and the internet are tools, not a lifestyle'


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 Post subject: Re: Cheap Component Tester
PostPosted: Jan Tue 30, 2018 3:01 pm 
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Joined: Jun Fri 19, 2009 6:34 pm
Posts: 7959
Location: Long Island
Quote:
I wonder if it might have something to do with the onward march of technology? I have a Rigol spectrum analyzer that I paid just a bit more than a grand for. I also have a couple of 141T's by HP. These cost in the neighborhood of $75K when new. Within its frequency range, the Rigol does everything the 141T does and more and it fits nicely on my bench.

My $20 whiz-bang gadget from China displays capacity accurately as well as ESR. Would it work for caps in the small pF range? Probably not.... but neither would any of the DMM type capacitance testers that cost a lot more. I trust my little gadget.... and I have never been steered wrong yet.


False equivalency. Rigol is in the business of building serious spectrum analyzers and other instruments, not training students how to design PIC microcontroller projects.

You might not want to read this, but if your $20 tester has not steered you wrong yet, you haven't used it very much or you've been lucky. From an engineering perspective, it's a toy. All measurements are taken across one of two fixed resistors which are 5% parts on most of these boards. Vcc varies about 5% and the internal reference for the analog to digital converter is 1%. So before you even get to the analog-to-digital converter, things could be off as much as 10%. That 10-bit A/D converter gives about nine bits of true accuracy due to rounding. The least significant bit represents about 0.4% of the reading which isn't bad if you happen to be using it, but if a reading is only using a few of the most significant bits, the measurements could be off 10%, 25%, or more depending on how many bits are actually contributing to the reading. Even inexpensive DMMs have 16-bit or 20-bit A/D converters with range switching or pre-scaling to ensure a reasonable number of bits are used at all input levels. Practically speaking, for some measurements this device will be within a few percent, but on other measurements it will be off by miles.

For measuring inductance or capacitance, the resistors are in series and the PIC is measuring charge time, not true L or C. Might be okay if you are measuring perfectly ideal components, but if they have some series or shunt (leakage) resistance, all bets are off. It should also be noted that these testers apply reverse voltages to determine the type of component. Applying five volts of reverse voltage to a tantalum capacitor that was not intended to withstand more than a volt or two backwards will void its warranty. If it wasn't bad before you tested it, it is now.

As for semiconductor testing, it's still the same two resistors and fixed Vcc, so it measures beta or transconductance the same way for all transistors, appropriate or not--and the same sources of error still apply. The levels do not correspond to data sheet levels in many cases so it's hard to make comparisons between the readings and published specs. In addition to the potential harm to specialized small signal diodes mentioned above, low noise transistors are also easily turned into high noise transistors by forcing reverse voltage on them. Old germanium transistors are not as forgiving about reverse voltages as the newer silicon ones are either.

So what you've got is a gadget that can look at unmarked, unknown components, determine (most of the time) if they are resistors, capacitors, inductors, diodes, or transistors, and give you an idea of the magnitudes of their values. Good for sorting out junkboxes and "bench sweepings," but I hope you held onto your DMM and other test gear for serious work.

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"Hell, there are no rules here--we're trying to accomplish something!"

Thomas A. Edison


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 Post subject: Re: Cheap Component Tester
PostPosted: Jan Tue 30, 2018 6:12 pm 
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Joined: May Tue 30, 2006 4:46 pm
Posts: 9441
Location: Santa Rosa, CA
Quote:
So what you've got is a gadget that can look at unmarked, unknown components, determine (most of the time) if they are resistors, capacitors, inductors, diodes, or transistors, and give you an idea of the magnitudes of their values. Good for sorting out junkboxes and "bench sweepings," but I hope you held onto your DMM and other test gear for serious work.


I mainly use mine for sorting, but it is "good enough" for the little receivers that I like to build. I liked my AADE much more, but alas, mine is toast and they aren't made any more.

Someone who has never seen a lab full of H-P and TEK equipment will probably find that the little gadget is "good enough" for home projects.

I just joined 180 Studios, which has a "maker" lab loaded with Keysight, HP, and Agilent gear. I am beginning to use the little Keysight EDUX scope that has function generator and signal generator built in and lists for $450! https://www.keysight.com/en/pdx-2766390 ... =US&lc=eng

Image

Rich


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 Post subject: Re: Cheap Component Tester
PostPosted: Jan Wed 31, 2018 2:52 am 
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User avatar

Joined: Nov Mon 02, 2009 7:01 am
Posts: 3044
Location: Lincoln City, OR
Greetings to Chris 108 and the Forum:

I stick by my original post... I think the technology has passed well beyond the original simple lab project. My tester will display capacitance, ESR and power factor.... hard to do if you are simply measuring charge time with a series resistor.

I mostly use it for measuring electrolytic caps... you know, +80 -20% and characterizing bi-polar semiconductors from the junk box. I avoid tantalum capacitors as much as possible.... and I don't use any parts rated at less than 5 or 6 volts, so I haven't had any problems there.

Perhaps it is just due to the sort of work I do, but I find the gadget highly useful and satisfactorily accurate for my needs. As I mentioned, if I were working on resonant circuits, I would probably get out the Tek 130, but for most of the work I do the gadget is just fine... and since virtually all of the DMM style meters I have seen (and I only own one with the capability to look at capacitance) have an upper limit of 200 uF or so, I find my little gadget to be much more useful.

Regards,

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KB6GM


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 Post subject: Re: Cheap Component Tester
PostPosted: Jan Wed 31, 2018 3:01 am 
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Joined: Jun Fri 19, 2009 6:34 pm
Posts: 7959
Location: Long Island
Quote:
Someone who has never seen a lab full of H-P and TEK equipment will probably find that the little gadget is "good enough" for home projects.


Really? You would give somebody who doesn't know better an instrument that may be within 1% accuracy on some readings and then be as much as 50% off on other readings? Sounds like tough love to me!

For a couple of dollars--or free if you have a coupon--one could own a little Harbor Freight DMM that has a bigger resistance measuring range and will be extremely accurate from one end of it to the other, and can measure voltages and currents in addition. For about what these PIC component tester gadgets cost, one could buy a bigger DMM from the same place that measures capacitance more accurately and tests transistors too. Okay so it won't sort the leads or automatically tell you NPN or PNP, but at least it will give real world readings when it does work.

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Thomas A. Edison


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 Post subject: Re: Cheap Component Tester
PostPosted: Feb Fri 09, 2018 12:37 pm 
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Joined: Nov Wed 09, 2011 4:07 am
Posts: 586
Location: MD-DC 20855
I have three or so of the inexpensive Chinese testers, and feel like they
were all money well spent. I also love my old AADE and use it the most.
It's just a little easier to use in practice and is my go to tester usually-
but at least one of the Asian testers does fairly large electrolytic caps and
even esr on them. For quick and dirty tests on garden variety transistors
they are hard to beat. I'd definitely buy them again...

The inexpensive frequency counters are also worthwhile IMO. I have
several. Amazing value...

David

P.S. For more 'serious' measurements, I bought a used Tek 465B, also
used HP 3466A and Fluke 8050A true rms DMM's over the years...

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 Post subject: Re: Cheap Component Tester
PostPosted: Feb Fri 09, 2018 2:43 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 17772
Location: Albuquerque, NM 87123
Chris108 wrote:
Quote:
I wonder if it might have something to do with the onward march of technology? I have a Rigol spectrum analyzer that I paid just a bit more than a grand for. I also have a couple of 141T's by HP. These cost in the neighborhood of $75K when new. Within its frequency range, the Rigol does everything the 141T does and more and it fits nicely on my bench.

My $20 whiz-bang gadget from China displays capacity accurately as well as ESR. Would it work for caps in the small pF range? Probably not.... but neither would any of the DMM type capacitance testers that cost a lot more. I trust my little gadget.... and I have never been steered wrong yet.


False equivalency. Rigol is in the business of building serious spectrum analyzers and other instruments, not training students how to design PIC microcontroller projects.

You might not want to read this, but if your $20 tester has not steered you wrong yet, you haven't used it very much or you've been lucky. From an engineering perspective, it's a toy. All measurements are taken across one of two fixed resistors which are 5% parts on most of these boards. Vcc varies about 5% and the internal reference for the analog to digital converter is 1%. So before you even get to the analog-to-digital converter, things could be off as much as 10%. That 10-bit A/D converter gives about nine bits of true accuracy due to rounding. The least significant bit represents about 0.4% of the reading which isn't bad if you happen to be using it, but if a reading is only using a few of the most significant bits, the measurements could be off 10%, 25%, or more depending on how many bits are actually contributing to the reading. Even inexpensive DMMs have 16-bit or 20-bit A/D converters with range switching or pre-scaling to ensure a reasonable number of bits are used at all input levels. Practically speaking, for some measurements this device will be within a few percent, but on other measurements it will be off by miles.

For measuring inductance or capacitance, the resistors are in series and the PIC is measuring charge time, not true L or C. Might be okay if you are measuring perfectly ideal components, but if they have some series or shunt (leakage) resistance, all bets are off. It should also be noted that these testers apply reverse voltages to determine the type of component. Applying five volts of reverse voltage to a tantalum capacitor that was not intended to withstand more than a volt or two backwards will void its warranty. If it wasn't bad before you tested it, it is now.

As for semiconductor testing, it's still the same two resistors and fixed Vcc, so it measures beta or transconductance the same way for all transistors, appropriate or not--and the same sources of error still apply. The levels do not correspond to data sheet levels in many cases so it's hard to make comparisons between the readings and published specs. In addition to the potential harm to specialized small signal diodes mentioned above, low noise transistors are also easily turned into high noise transistors by forcing reverse voltage on them. Old germanium transistors are not as forgiving about reverse voltages as the newer silicon ones are either.

So what you've got is a gadget that can look at unmarked, unknown components, determine (most of the time) if they are resistors, capacitors, inductors, diodes, or transistors, and give you an idea of the magnitudes of their values. Good for sorting out junkboxes and "bench sweepings," but I hope you held onto your DMM and other test gear for serious work.



Chris, I'd like to know just where you get all this information. Do you do your own testing or do you have an engineering team collecting data for you?

* "all measurements are taken across one of two resistors which are 5%."
* Vcc varies by 5%."
* ....If it wasn't bad before you tested it, it is now."
* low noise transistors are easily turned into high noise transistors."

OK, what do you base these statements on?


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 Post subject: Re: Cheap Component Tester
PostPosted: Feb Fri 09, 2018 3:48 pm 
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Joined: Jan Mon 28, 2013 9:35 pm
Posts: 1104
Location: Santa Rosa, CA
Not really sure where Chris is coming from on this but real
measurements I've made where I compare my two el-cheapo
chinese testers to my lab grade equipments has given me a lot
of confidence in their accuracy. Generally speaking well within
5% for inductance, capacitance (including ESR), transistor beta and
resistance measurements. The one exception is low value resistors,
under 50 ohms.

These testers use *fundamental* measurement principles. Not to be
confused with lab grade equipment that often has elaborate calibration
software correction or dual slope A/D conversion. If one needs exceptional
accuracy or standards tracability there is no replacement for properly
working and professionally calibrated lab instruments. No one is saying
these chinese testers do this.

However these chinese testers have the capability to do what a bench
full of lab grade equipment can in a very small package for a very
low price. Why not use them?

I use mine primarily to measure inductors and their resistance, caps
and their ESR, transistors and their beta (and to find matched pairs).
Show me a single lab grade instrument that can do this. And do it
fast, accurately, with one set of connectons and cheap.
Steve

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'cell phones and the internet are tools, not a lifestyle'


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 Post subject: Re: Cheap Component Tester
PostPosted: Feb Fri 09, 2018 5:23 pm 
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Joined: Nov Wed 30, 2016 7:35 pm
Posts: 2158
Location: Sunbury, Ohio 43074
......watching with interest. I sort of detect two different conversations going on. But it all seems to boil down to the differences between what a hobbiest, tech, and/or restorer might use, and what a design engineer might use. Likely two completely different things, no ?

If absolute precision is your requirement, and you are designing equipment for "higher end" applications where such accuracy is important, then I'd side with that half of the discussion. If you want to sort out your junkbox, or "get things working" that once DID work, I'd side with the other.

When faced with headache inducing analysis, I always tend to KISS (y'all know what that means! ;0) )

The forum includes everything from new entrants into electronics that cannot tell a resistor from a diode, to design engineers making microwavve spectrum analyzers from parts found around the home. And everything in between. I doubt there is a "one solution fits all" here. But a newbie will get quickly lost and befuddled, to say the least, when faced with too much technical detail :)

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 Post subject: Re: Cheap Component Tester
PostPosted: Feb Sat 10, 2018 12:05 am 
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Joined: Feb Sun 10, 2013 3:31 am
Posts: 50
That tester has been discussed on this blog and many others. The Component Tester is based on the project of Markus Frejek. The definitive source of information is here:

https://www.mikrocontroller.net/article ... stortester

There is introductory information in German, English and French. Additionally, several other languages are supported for the software.

Or, use Chrome browser to translate the main page page to English.

A blog, now in its 5th year maintains current (and historical) progress on this project:

https://www.eevblog.com/forum/testgear/ ... ject/4450/

The ongoing software and hardware development is documented on the EEV blog. Currently, two software development lineages are maintained by two developers, both of which support the hardware of the typical units on eBay, Amazon and elsewhere.

The current hardware is based around the Atmel AtMega328, not a PIC microcontroller as one poster here stated. Earlier AVR devices were originally used. For details, one needs to read about 10 pages or so of the EEV blog. There are currently 182 pages on the blog, and new interested parties are advised to go 10 or 15 pages from the latest end. The status of the project is routinely updated with hardware and software version updates. The mathematics bases for the measurements by the device is fully explained, along with the ongoing work toward precision and accuracy.

If you go to the 1st page of the blog, you will see one of the original devices with a 2 line by 16 character LCD. As of the last time I read through the blog, that display is still supported as well as the current displays on the market.

The hardware and software are both open source, hence the number of versions. Occasionally in the blog, there is reference to specific boards from China that are known to function well and can be updated by removing the DIP package 328 out of the circuit, or in the circuit. Several versions use a surface mount 328 that can be flashed in-circuit.

Ted, KX4OM


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 Post subject: Re: Cheap Component Tester
PostPosted: Feb Wed 14, 2018 12:16 am 
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I kind of chuckle to myself at these threads about needing serious equipment that cost $75K new when the name of the Forum is Antique Radios 8)


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 Post subject: Re: Cheap Component Tester
PostPosted: Feb Wed 14, 2018 6:33 am 
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Joined: May Tue 30, 2006 4:46 pm
Posts: 9441
Location: Santa Rosa, CA
You can't possibly shoot a reasonable game of golf unless you have at least $5000 worth of clubs and $300 shoes.

I like my little component "sorters" and they help me build fun circuits and find useful junk at flea markets.

Rich


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 Post subject: Re: Cheap Component Tester
PostPosted: Feb Fri 16, 2018 5:40 pm 
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Joined: Jun Fri 19, 2009 6:34 pm
Posts: 7959
Location: Long Island
Bought a brand new component sorter off eBay for somebody. Spent half an hour peeling the protective paper off the plastic pieces of the case, put the board inside, and hooked up a fresh new battery. Backlight comes on nice and pretty green and turns off after about 20 seconds. But nothing ever appears on the display!

What kind of component tester do you use to test your component tester?!? :?

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