Ages and ages ago, a coworker brought me his Fender Frontman Reverb amp saying it didn’t work. He had a second one that did work, so there wasn’t any rush to get it working, so I took the unit home, and went to work on it. Disassembly was easy enough, and finding the schematics showed that the unit was identical to the Fender Frontman 15R, which has schematics (in the service manual) here. The US Fender site SAYS it has schematics for the 15G-15R, but only the 15G is shown, meaning the whole reverb section is left out. =/
Archives for April 2016
A coworker recently gave me his Fluke 8021B to repair as it had taken a fall ages ago, and the LCD had been damaged. Having seen a post ages ago on Mr. Modemhead’s site, I knew repairing the screen on the 8020A was doable, and figured the 8021B would be identical as far as screen.
The problem, actually, is the LCD holder is surprisingly different (much more sturdy). So after I ordered and received the LCDs, I went about “machining” the LCD holder to let it fit. This took grinding off part of the “top” where the pins would lay, and several other ribs to allow the LCD to sit “flat” on the holder1. Wiring the LCD, I used two colors of 30AWG wire, and a wire wrap tool (that I hadn’t used before). I used two colors of wire to help differentiate between the bottom and top pins. I also, breaking from Mr. Modemhead’s page, drilled small holes in the LCD holder to feed the “bottom” wires through, and to help keep them in order. Stripping the wires, then soldering to the PCB was annoying, but not overly time consuming. I also had to re-solder the “COM” jack on the unit since it had worked loose enough to “spin”. This is very easy to do, as you just put the soldering iron IN the jack, let the whole thing get nice and hot, and then touch solder to the bottom side, then the top side, and let it cool. I did have to “machine” the plastic of the top case a bit to let it clear the new solder, but it worked just fine, and was now solid. =)
- As noted later, I actually didn’t do enough the first go around [↩]
At a local thrift store recently, I came across an “Energy Concepts, Inc” 30820 for next to nothing ($15). They let me plug it in, and I got two traces, so at that point I felt it was worth buying (hell, I would have bought it if it didn’t work, just so I could fix it). Bringing the unit home, and doing some looking around, it appears to be an Iwatsu 5702 (which is why there’s the Iwatsu pictured to the left). I cleaned the unit up (compressed air, and a rag), and went about testing it’s functionality. It appears to have been owned by the local school district, and I confirmed that the High School in question recently received a STEM grant, so it makes sense that they would have upgraded their equipment.
The unit tested perfectly, being well within calibration on everything I threw at it. The traces were nice and bright. The only downside really being that it came with no probes (I purchased a couple off eBay for $8 shipped), and that being a completely analog scope, it had no measurement capabilities. It also is missing the red time position knob, but that’s no big deal as the shaft of the adjustment is still adjustable by hand, and someday I’ll find something to fit there.
Really, the unit works great. And I look forward to using it and maybe having it be my son’s first scope (generally, analog scopes are pretty indestructible).
For those interested, here are links to the manual, and service manual for the Iwatsu SS-5702, which again, seems identical to the ECI, other than the handle being on the side of the Iwatsu rather than the top like the ECI.