Membrane keypads again.

The solution that I use for this issue, typically, is to strip a small piec e of fine gauge (appropriate to the MPC) copper wire -leave it on the spool for leverage - preferably hardened, and I keep a couple of small spools _o nly_ for this purpose, and push it down the connector beside the broken wir e. Touch this wire with a hot iron and a bit of solder to bridge the break, and then cut it off with fine nippers. If the MPC is very fine, I will pre

-tin the wire as it may not flow down the hole. If and then, a bit of hot-m elt or similar to insulate any exposed wire. Done.

I have been known to use a silver-plated sewing needle, broken off to the p roper length if copper would be too soft. They solder very nicely.

Peter Wieck Melrose Park, PA

Reply to
pfjw
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Excellent, will try. Thanks!

Reply to
bitrex

OK, so the mystery deepens a little bit. I was having trouble getting the shimming to work consistently, so I tried jumpering directly from the control wire to the underside of the PCB.

Turns out that there's still a problem, even with the wire jumpered directly to the board. But when I pinch the wire junction in my fingertips, everything works normally.

Pull-up resistor gone open on that line, maybe?

Reply to
bitrex

Yup, that was it. Pullup resistor on that pin has gone bad!

Reply to
bitrex

Yup, that was it. Pullup resistor on that pin has gone bad!

I said that quite some time ago.

R66 is most likely contrast or viewing angle adjustment. It might be a good idea to check all the pullup resistors (RA3) are all present and correct.

Gareth.

Reply to
Gareth Magennis

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