Computer Cleaning

December 9, 2017

Just yesterday, one of the computers in the house wouldn’t turn on… All the computers are set to run diagnostics at night and then turn off. If I’m the last one up at night, I’ll turn off the UPS for the associated computer. Since I’m not usually the last one up it doesn’t happen that [...]

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LM3916

December 9, 2017

Dot/Bar Display Driver The LM3916 is a monolithic integrated circuit that senses analog voltage levels and drives ten LEDs, LCDs or vacuum fluorescent displays, providing an electronic version of the popular VU meter. One pin changes the display from a bar graph to a moving dot display. LED current drive is regulated and programmable, eliminating [...]

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Test Equipment

December 8, 2017

What Test equipment should I have and what tools should I have on my workbench? If you’re starting from scratch, there are a number of things you’ll need to have. Multi Meter As far as test equipment, you need to have a good Voltmeter. Notice I didn’t say digital, I said “good”. So how do [...]

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Fixing Other’s flubs

December 8, 2017

I have a 42″ LCD TV made by Olevia. Just after it finished it’s warranty period it died. I didn’t have time to devote to fixing it because of other commitments so I took it to a shop for repair. After looking it over, the owner told me it would cost $300 to fix because [...]

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Troubleshooting (part 5)

December 7, 2017

Documentation I’ve been talking about this for a while.  I even offered up some suggestions in my previous post about how to possible modify the trouble shooting procedure.  Here’s another alternative.  I’ve used both methods and, for me, it’s a toss up.  I think I prefer this method a tad bit more as I can [...]

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Troubleshooting (part 4)

December 7, 2017

So How did you do?  Did you build you troubleshooting guide for no Power?  Did you start?  I hope so, the best way to do anything is to “jump in” with both feet or “go for it”. Nike’s ad is in a similar vein: “Just Do It” As promised, I’ll show you my troubleshooting

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Tips

December 6, 2017

As I think of tips I’ll post them and once I get enough, I’ll collect them on a single page so that they’ll be easier to find.  You may have noticed some random part numbers appearing on the site.  Since I’m always taking things apart and figuring out what they do, I’ve decided that I’d [...]

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Moribund Microwave Oven

December 6, 2017

Way back when, before wife and kids, after college, 1985 to be exact I bought a microwave oven. It was a Sharp model with a rotating carousel. The carousel was rather unique, and most ovens didn’t have one. You were required to stop cooking and rotate the food periodically to ensure even heating. The carousels [...]

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Troubleshooting technique (part 3)

December 5, 2017

(…continued)As I mentioned at the end of the last post, I’ve never owned an electronic repair shop.  In addition to all the things I mentioned in that post, I’ve worked in the military aboard nuclear submarines, I’ve worked in the chemical industry and the semiconductor industry.  In every case, the success of the organization has [...]

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2N2222 / 2N2222A

December 5, 2017

General Purpose NPN Transistor 2N2219A, 2N2221 and 2N2222A are silicon planar epitaxial NPN transistors in JEDEC TO-39 (for 2N2219A) and in JEDEC TO-18 (for 2N2222A) metal case. They are designed for high speed switching and small signal applications at collector current up to 500mA, and feature useful current gain over a wide range of collector [...]

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