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Archive for March, 2014

18
Mar

Under The Microscope

I’m doing more SMD work (that’s using very small surface mounted electronic parts) and checking my work, even with a headset magnifier is difficult. I’d purchased a “budget” USB microscope from fleaBay last year but apparently you don’t get a lot of quality for $12. Surprise…

I’d read that the 5mp cameras with a 50-500x magnification and controllable LED lighting are the best way to view your stuff, so, I ordered a USB microscope:

USB Microscope

Of course when it showed up, the first of note was the total lack of Mac support. There was a MINI CDROM for Windows though and I did manage to install that in VMWare Fusion under WinXP to make sure the thing worked. The software is sort of “iffy” though with a non-intuitive interface. But then I find my Windows application tend to look cartoonish and sport functions they don’t explain. Anywhere, including the “Help” menu. Begs the question of why put in a Help menu in the first place.

For the Mac, there are some software choices, none of which I could find that take advantage of the two push buttons on the microscope. Namely SNAP and ZOOM. I was sort of disappointed until, I realized that when you’re hitting those buttons at a high magnification, you shake things. A lot. Thus, they are really kind of useless.

I found that the Macs PhotoBooth and Quicktime could use the “USB Camera” so all wasn’t lost after all. The third party software for the Mac didn’t really appear to have a lot of options I’d use any way.

While this microscope had good clarity and ample zoom, it also had a problem. A flickering set of LED ring lights inside. There is a POT on the cable that allows you to adjust the brightness, hopefully to get a better photo or image. If I wiggled the cable where it went into the microscope head, the lights would flash on and off. Like an intermittent connection. Not good.

I naturally contacted the eBay seller who offered me $5 to buzz off. Or ship it back at my expense (about half of what I paid for the scope). Eventually we settled on a higher amount and I thought I’d just build my own LED lighting for it.

This thought lasted an entire afternoon. Indeed. It bugged me. So, rather than leave things alone, I ripped it apart to see what the problem was.

I started by taking apart the pot that controlled the LED brightness. Not much to it.

IMG 4559

Getting the main unit apart. I got the silver ring off first (it’s around the unit by the Snap switch in the first image). Once I got that off, the end with the cable in it is sort of glue welded and it was easy to pry off the cable end.

IMG 4560

There was a metal clip that looked like it was trying to cut the cable in half that I removed. You can see the indentation in the cable. I used a zip tie to replace it. When I wriggled those wires the LED’s would flash. I thought it might be the main board or something so I started to look inside:

IMG 4562

I thought Behringer was the only company that used glue to hold little pieces in place. Nope. The blue and yellow wires are from the POT. I checked as best as I could for a bad connection but couldn’t find one.

It was when I started to look closely at the pot, I found the Blue wire was a cold solder joint. I resoldered both connections anyway and now it works just fine.

I put it all back together, used the Handyman’s Secret Weapon to hold the cap on (duct tape).

Previously I said that using the buttons on the unit are pointless because you shake too much (or I do). The best way to do it is to set it up on it’s El Cheapo stand, prefocus it, then slide a printed circuit board underneath the lens and don’t touch the microscope at all. The Mac Quicktime application works better than the PhotoBooth one. In PhotoBooth images are flipped and reversed.

My advice if you get one of these, see if you can find one with a VERY sturdy stand. I’m going to make a stand for mine out of wood. That will hold it very steady. And really that’s about all you need. It actually works quite well and the LED’s brightness control is very handy.