Ok I will.
Yes they did blink out and back on. One row, when i removed the plastic
stayed off and slowly blinked back in, as if the alastomer as expanding
back out.
Some of the alastomer feels really elastic while the areas of failure
feel hard. I will make a video of the action and share it.
I know that the metal enclosure is held by twisted ends. Is that
enclosure's removal ill advised? I'm sure it is.
On 4/11/20 7:03 PM, B4 Me100 wrote:
Hmmm, the only thing to try is increasing the pressure slightly to
force more movement in the elastomer.. Also make sure the plastic is
moving the elastomer.
Did the other rows blink out and back on as you move along the
elastomer strip?
From: M100 <[email protected]
<mailto:[email protected]>> on behalf of me
<[email protected] <mailto:[email protected]>>
Reply-To: <[email protected] <mailto:[email protected]>>
Date: Saturday, April 11, 2020 at 6:44 PM
To: <[email protected] <mailto:[email protected]>>
Subject: Re: [M100] Missing ROM elements
Okay. I sacrificed some plastic packaging and slid it in there
with some cleaner. no joy. I spent probably 25-30 minutes doing
it. i'm going to let it sit for a while and try it again. I have a
honeydo list in the meantime.
Your explanations were very straight forward and I appreciate it.
It doing this doesn't fix my problem, do you have any other
suggestions? I did some mild twisting of the pcb and didn't notice
any difference.
Meanwhile I have a 200 incoming that I look forward in using. It
may suit my targeted needs more so than the 100. I have plans for
the 100 though, once i can see the entire screen.
On 4/11/20 8:06 AM, B4 Me100 wrote:
That worked :)
The contacts run top and bottom of the screen there are none on
the side of the screen. If you have the TRS-80 Model 100
Reference Manual page 75 has a picture of the top of the circuit
board showing the contacts (link:
http://www.classiccmp.org/cini/pdf/Tandy/Model%20100%20Tech%20Reference.pdf
<https://nam05.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.classiccmp.org%2Fcini%2Fpdf%2FTandy%2FModel%2520100%2520Tech%2520Reference.pdf&data=02%7C01%7C%7C9a4683990cf5454f131708d7de832530%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637222527150781330&sdata=Yu75VKucOg0r2yt3D1rcDiYVfknv5yZHUIEFwOe7iqk%3D&reserved=0>
) - they are tiny gold fingers on the board. The elastomer has
bundles of vertical conductors buried in it that take the signal
from the board to the bottom of the LCD glass panel and the
transparent traces that run on the screen glass panels – you can
just see them in the video. There is also schematic for the
screen in the reference manual showing how it is arranged and pg
34 provides some more details on the arrangement. Because the
units are so old the elastomer has started to harden which means
it no longer presses onto the board as well as it once did. It
may also depend how the unit has been stored during its lifetime.
The oxidation generally occurs at the PCB to elastomer contact
and a little gentle movement can sometimes clean it out and make
a good contact once again. The de-oxit just helps with the
process. It may take a few attempts to clean it so take your
time and make sure nothing shorts out on the bottom of the board
to anything else if you choose to perform the repair powered.
The card has to be thin enough to fit between the metal of the
screen surround and the PCB but strong enough to apply a little
force to the elastomer. It is hard to get at some locations,
particularly the ends, because the metal clips are in the way.
As you slide the card along you should see the rows/cols blink
off and hopefully the bad rows/cols come back to full operation.
The cols and rows that are out in the video are on the bottom
strip.
From: M100 <[email protected]
<mailto:[email protected]>> on behalf of me
<[email protected] <mailto:[email protected]>>
Reply-To: <[email protected] <mailto:[email protected]>>
Date: Saturday, April 11, 2020 at 1:07 AM
To: <[email protected] <mailto:[email protected]>>
Subject: Re: [M100] Missing ROM elements
woops i accidently unshared it
https://www.omgwtflol.net/nextcloud/index.php/s/7tM2KkR3Q5bCQXf
It's reshared. Stupid me.
On 4/10/20 9:15 PM, B4 Me100 wrote:
The link takes me to a login screen? Is there part of the
link missing.
From: M100 <[email protected]
<mailto:[email protected]>> on behalf of me
<[email protected] <mailto:[email protected]>>
Reply-To: <[email protected] <mailto:[email protected]>>
Date: Friday, April 10, 2020 at 4:38 PM
To: <[email protected]
<mailto:[email protected]>>
Subject: Re: [M100] Missing ROM elements
https://www.omgwtflol.net/nextcloud/index.php/f/108057
