Re: [M100] M100 repairs (LCD, keyboard)

[Louis Ciotti]

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 On Wed, Apr 19, 2023 at 4:18 PM Gregory McGill <arcadeshop...@gmail.com> wrote: Cool can you share the part  On Wed, Apr 19, 2023, 11:35 AM David Plass <dpl...@alum.mit.edu> wrote: To answer my own questoin _again_, about half the function keys were toast, but they seem to be a standard part (!) so I was able to order some replacements.  On Mon, Apr 17, 2023 at 9:00 PM David Plass <dpl...@alum.mit.edu> wrote: Thanks. To answer my own question, the 1N4148 diodes worked perfectly. All the regular keys are working. The function keys, not so much. I've squirted lots of electronics cleaner and clicked each switch dozens of times and only a few of the 7 or so broken switches have come back. Right now I dripped some vinegar inside to hopefully break up whatever corrosion might be inside...  On Sun, Apr 16, 2023 at 7:45 PM Brad Grier <b...@bradgrier.com> wrote: RE: the polarizing film -- Jeff Birt (on this list) suggested https://3dlens.com/ I have some, just haven't got to my project that needs it yet :D and with the onset of spring, that one may sit for a bit. --Brad On Sun, Apr 16, 2023 at 2:10 PM David Plass <dpl...@alum.mit.edu> wrote: I couldn't resist a recent M100 on ebay listed as "not working". The main issue was a dead contrast pot, which I have temporarily worked around and ordered a hacky replacement. The polarizing film is also very bubbly and no amount of smoothing made it stay flat on the LCD. Is there a known replacement for the film? Most importantly, I noticed about a half dozen non-functional keys. After disassembly I discovered corrosion on their diodes. Upon closer "inspection", said diodes disintegrated.  So my second question is: Is there a particular diode I should replace them with? I have tons of 1N4148s, which look like a match (and electrically drop about the same voltage), but I can't find a spec for those diodes on the m100 schematics. Thanks -David -- --  Brad Grier