Re: Power light on Apple II

["Michael J. Mahon" <mjmahon@aol.com>]

Kallikak wrote:
> I have 2 Apple II+ keyboards, but each has an irritating minor fault.
> One has a dodgy spacebar because a bit of plastic has broken off that
> should hold the metal support in place beneath it, and the power light
> doesn't display on the other. I like the feel of the second one much
> more than the first, but it's a bit awkward to not have any visible
> indication of the machine being switched on.  I know the lamp is ok
> because if I put it in the other keyboard it works.

Then the problem is a continuity fault between the keyboard connector
and the lamp--probably a hairline crack in the PC board, a broken wire
in the cable/connector, or a cold solder joint.

You can find it by bridging parts of the path until the light
illumnates, then reducing the amount bridged until you've found
the fault.  Close physical inspection may also reveal the problem.

> I was interested in advice relating to the difficulties I may
> encounter if I completely dismantle the keyboard and try and find the
> fault.  I really don't want to mess up an otherwise working keyboard,
> and I am quite wary since the first thing I did was to slightly (only
> slightly) tighten a couple of screws beneath the area near the power
> light position and that stopped about 4 or 5 of the left hand keys
> from working at all.  :-(

I would expect that the problem could be isolated without having to
disassemble the keyboard very far.

-michael

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