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bigmik

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Joined: 20/06/2011
Location: Australia
Posts: 2971

Posted: 01:08am 05 Jul 2021

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Hi Mick,

It should be fairly easy to do the mod by cutting the ribbon with a sharp scalpel and straight edge as shown below.

then heat Pin 8 where it joins the PCB to lift the new strip up, put a strip of insulation (tape?) under the pin 8 flap so it wont reconnect with GND and run a wire as suggested to the BLK pin (assume this is BLANK?) and remove the relevant resistor. If you wish to use the BLK feature then run CS directly to pin 8 on the ribbon (the new sliver) and secure with something to stop it tearing (nail polish), I know all techs wear nail polish, i have seen it in their kits and I have several colours myself.

Regards,

Mick

Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<<

Chopperp

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Joined: 03/01/2018
Location: Australia
Posts: 1106

Posted: 01:50am 05 Jul 2021

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bigmik said I know all techs wear nail polish, i have seen it in their kits and I have several colours myself.

Regards,

Mick

I went & bought a bottle of bright red & bright green the other day. On special at the Chemist (Drug store). I had run out....
Edited 2021-07-05 11:51 by Chopperp

ChopperP

Mixtel90

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Joined: 05/10/2019
Location: United Kingdom
Posts: 8297

Posted: 06:37pm 07 Jul 2021

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Mick, thanks! You're a star! All is well now. :)

That method of separating connection 8 of the ribbon works well. :)
It wasn't an easy mod for me - not the sort of thing I'd want to do much of. Squinting through the small "extra strength" area of the magnifier while holding the little pcb in position and wielding a scalpel wasn't fun. lol

I cut the track rather than remove R2. That will allow me to solder a bit of flexible wire onto R2 to give BLK operation if I decide to use it. It also means that I won't be straining the ribbon cable any further.

No nail polish was harmed in the making of this modification.

Edit:
Contrast on this display isn't all that good so I've experimented with driving BLK with a PWM signal, which works well. Contrast still isn't good, but at least the backlight is controllable. :) A neutral filter of some sort helps - 2 layers of anti-static bag is a definite improvement.
Edited 2021-07-08 07:19 by Mixtel90

Mick

Zilog Inside! nascom.info for Nascom & Gemini
Preliminary MMBasic docs & my PCB designs

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