Model 100, again

From: jpero_at_cgo.wave.ca <(jpero_at_cgo.wave.ca)>
Date: Mon Nov 17 08:58:39 1997

> At 01:32 AM 11/17/97 +0000, you wrote:
>

> Jason,
> This is good advice, but:

> *If* the M100 display is similar to the Tandy 200 display, they are _not
> screwed together._ They are held together by a cheap pot-metal bracket with
> nothing but tabs pushed thru slots on the LCD controller PCB and then
> twisted. You will get 1, maybe two twists on each before they break. These
> tabs must be *firmly* twisted to gain enough pressure on the LCD for the
> pressure sensitive glass contacts to work.
That rubber striped thingy are called zebra connectors. Used in lot
of hard drives with a zeal especially early Maxtors, few quantums and
few others. It's not pressure sensitive, the electrical connections
is made by pressure. Long edge takes lot of pressure to do it
because of area. Physics duh!
 
> I had a badly misaligned T200 display that I attempted to realign...
> realignment is not as easy as it would seem, and yet on my 3rd attempt it
> was *perfectly* aligned. I had all of the tabs twisted back with decent
> pressure and it was still holding... then, alas, the *last* tab broke, and
> it was close to a corner, easily wiping out 10-15% of the display. It was
> already a lost cause so there was nothing to lose, but I speak from
> experience -- it's tough to bring these LCD's back from the dead.

They're built to be mass-produced which means it has lot of hardware
supports in that display frame and I kid you not, it's tin sheet and
easily soldered. You could anneal it. Rub/dab all contacting points
with new swabs dipped in 99% alcohol (easily had from paint hardware
store). If the PCB used plain tin or plain brass instead of gold
plated pads, you need to scrub it hard to remove all oxidiation.
And Yes, please gently clean all zebra connectors as well. I have
repaired both watches, clocks and calculators like that. Also, I saw
there are marked alignment crosses on both glass and PCB in some
displays especially large ones but usually it's just physical frame
alignment that lines up if you really carefully straighten out any
manufacturing errors clamping frame. If the frame is not solderable
to make new tabs, consider clamping it with strong homemade c band
scrapped out of old cheap bed wind up clocks. When I was trying to
repair a compaq LTE Lite backlight, I found 2 pieces of LCD module
that you can view from both sides with driver chipsets all built into
2 or 3mm thick. Seperate backlight module consists of single
fluorenscent tube taped to light diffuser module on one long edge.
Neat. But is that fluorenscent tube all used up if it takes "years"
to warm up to 65% brightness with uneven brightness on one end and
dark on other end? If I touch with conductive probe on primary side
controller to specific point, it brightens up bit but can't use
brightness control like that.

Mighty Bitten off! :)

Troll

> "Merch"
> --
> Roger Merchberger | If at first you don't succeed,
> Programmer, NorthernWay | nuclear warhead disarmament should *not*
> zmerch_at_northernway.net | be your first career choice.
 
Received on Mon Nov 17 1997 - 08:58:39 GMT

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