It takes a microscope to fix a microscope. At work we have some Targano brand digital microscopes. They work well, and make a very good clear image for doing soldering work, but I have some gripes with their design. Not the loads of real working room below the imager, or the clear nice image it makes, but it SUCKS to repair this thing, and it's easy to break. A few weeks ago someone bumped into the scope at my friendly local soldering workbench trying to help with a video issue, and the microscope stopped working. Here's the ailing peeper of things:
Unfortunately ours does not hover 2" above the tabletop, but what it does do is require you to plug a mini-HDMI cable into it's side like sticking a chest drain into a hospital patient with a collapsed lung. All that elegance in the marketing photo goofed by cable routing. I used our trusty old stereo fiber optic lit bench mounted look-sniffer to take a deep sniff down the mini-HDMI video hole and smelled a few pins that were bent by the right-angled and undersized cable getting a downward torquening.
Good old 'Ol-Reliable. You're always ready. With the problem understood, and with a heavy heart I ordered the cheapest 10 pack of mini HDMI ports on ebay that seemed like a likely match to the footprint, and once they came in I set to pulling the Targano apart. WHAT A PAIN!. They must not be making tons and tons of these, because they're built with loads of fiddly gotcha kinds of plugs annoyingly squished and squeezed into the extrusions of the outer shell. Also, there's strips of gaffer's tape hiding video signal cables in the upper part behind the stage light LEDs.
Eventually after much fiddle-futzing I managed to extract the mainboard running the show, noting that screws to these threaded standoffs were held on not by their threaded holes, but by flush-tapered screws clinging for dear undersized life to a backing plate on the hinge assembly. Ehh, I've done hackier stuff, but with a "call us for a quote" price I'd expect a bit more serviceable and elegant design.... Either way, Next up was trying to improve my hot air work skills. masked off the area around the malign port with kapton tape, and promptly managed to hover somewhere between "smoldering black port plastic" and "The iron is set for 400c, why won't it melt?!" conditions. Eventually I got the old port removed, but it took 3 traces with it. Caramba.
With the old port out, a bit of fine solder wick braid made room for the new one. The image is better viewed in person in the microscope, but if you look carefully you can see the three missing traces to the fluxed up chips.
Look closely enough and you can see one of the patch wires i cut down to eventually fix the ripped pins. I tried using UV cure solder mask to glue down the traces and repair wires, but didn't manage to let them cure enough to be more than "glazed donut frosting" strong. Turns out that UV solder mask needs at least several minutes and the thinnest coat you can physically make occur to have a good chance of working.
With MUCH ARDUOUS REASSEMBLY, the scope went back together, and you can pirate my index finger if you like. That done, I went ahead and made a shroud for the cable so it's not easily borked again. If Targano reads this, please redesign the board to use a full sized HDMI port at least?
Just a bit of aluminum sheet bent around and zip tied to the cable with a space, and one more to keep it tightly pulled around the upright of the thing, Maybe it breaks the elegance of the design, but what good is that when it can't take a light bumping into without nearly destroying itself?
Pen Tip for scale, and spare mini-HDMI port for outrage. The hole in the case is sized big enough for it. Why not plonk a normal HDMI port on the board? Whatever. It's working again, and I only almost finished destroying it. Much clearer image on the Targano than the optical scope.
