It's no fun if it's too easy ;-) A shame about the pant & the extra effort; did you get all the switches working/replaced?
m On Sat, Apr 29, 2023 at 3:01 PM David Plass <dpl...@alum.mit.edu> wrote: > Latest update: > > I used lots of 99% IPA and got much (but not all) of the paint off the > keyswitches and PCB. I gave up after a while and decided it's good enough. > > I found a replacement contrast potentiometer. Its leads are a little too > short so it's too loose in the PCB and therefore intermittent, so I may use > a regular pot sticking through the hole, which is TBD. > > I derusted and painted the metal bracket at the top of the keyboard and > reassembled everything. > > Working off a wall wart, it was fine, but when I popped in some batteries, > it didn't turn on. > > I tracked it down to the barrel jack "interlock" failing, so it always > thinks there's a power plug inserted. I removed the old barrel jack and > installed a new one that is *almost* the right size. I'm going to have to > modify the case to get it to fit flush. > > Two steps forward, one step back, but it's still progress. > > > On Sun, Apr 23, 2023 at 5:37 PM David Plass <dpl...@alum.mit.edu> wrote: > >> An update: >> >> Unfortunately there was a freak accident in the workshop... I'm >> de-rusting some of the keyswitches and the on/off switch and figured after >> removing the rust I'd paint over the rusty areas (it's not ideal, but the >> best I could do). >> >> One of the switches was "clean" so I temporarily installed it on the >> keyboard PCB. To paint, I was going to use a silver "paint-pen". While >> shaking the pen (according to the directions), the pen exploded and >> splattered paint on the keyboard and PCB. About 4 switches were inundated >> with paint and another 2 or 3 got some paint splattered on them. >> >> I spent about a half an hour cleaning the paint as best I could using 99 >> IPA, but there's still some paint on the PCB. >> >> A few hours later I checked some of the affected switches and I think the >> paint has dried inside them, because they're open circuits now. I tried >> De-Oxit, and they are revived, but I fear it's only temporary. >> >> My question for the forumbrain is: can the keyboard switches be >> disassembled for 'deep cleaning'? I would desolder them first, obviously. >> >> Thanks >> >> >> >> >> On Thu, Apr 20, 2023 at 10:48 AM Gregory McGill <arcadeshop...@gmail.com> >> wrote: >> >>> thanks! >>> >>> On Thu, Apr 20, 2023 at 4:14 AM David Plass <dpl...@alum.mit.edu> wrote: >>> >>>> I was surprised too but it's a near exact match. I tried the key caps >>>> and, while they're tight, they definitely fit. >>>> >>>> On Thu, Apr 20, 2023, 6:25 AM Louis Ciotti <lciot...@gmail.com> wrote: >>>> >>>>> I would have never thought these would have been used back when the >>>>> M100 was designed. >>>>> >>>>> Sent from my iPhone >>>>> >>>>> On Apr 19, 2023, at 10:03 PM, David Plass <dpl...@alum.mit.edu> wrote: >>>>> >>>>> >>>>> The function keys are 12x12x7.3mm tactile switches with square tops >>>>> and PCB/through-hole mounting pins. >>>>> >>>>> For example: >>>>> https://www.amazon.com/TWTADE-Momentary-Tactile-Button-12x12x12mm/dp/B07CG7VTGD?th=1 >>>>> or >>>>> https://www.amazon.com/ACEIRMC-12x12x7-3mm-Momentary-Tactile-Arduino/dp/B091HL5YBD/ref=sr_1_3 >>>>> >>>>>
