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RE: Screen replacement
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Scott L Wilson
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May 21, 2009 08:06 PDT
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Dusan
Thanks again for your help!
Scott
On Thu, 2009-05-21 at 14:54 +0000, Dusan Mihajlovic wrote:
| | Scott,
When you open Wavestation AD, with the front panel towards you, you will
see on the left hand side a bunch of white wires (four or five) going
towards control panel. One of these is bringing positive voltage to the
top end of the contrast pot and the other connect the slider of the pot
to pin four on the 20-way paralel cable for the screen.
The purpose of the resistor is to lower the maximum voltage on the
positive end of the pot, so that the slider never goes to the full
positive voltage, so you need to connect it in line to the the wire
bringing the positive voltage to the pot. It is not important where you
fit the resistor but to make all the connections reliable.
Good luck,
Dusan
Scott L Wilson wrote:
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Dusan
Thanks for the display tip. I just bought one. Would you be so kind as
to describe where the 10k resistor gets soldered, just so the contrast
is right?
Thanks very much for your help!
Scott Wilson
On Wed, 2009-05-20 at 22:30 +0000, Dusan Mihajlovic wrote:
| | I purchased the screen from:
http://www.zinguy.com/lcdpage.htm
based on the description of replacing SY77 screen I found on the net - I
think on EX5 discussion board.
The description doesn't quite work for TG77 since the oscilator crystal
on the back of the screen is too high, so I needed to do some soldering
and than everything worked fine. Not reqlly a job for a soldering iron
beginer since you also need to find a source for +5V to supply the LED
with power.
However an avaradge electronics technician should be able to do a job in
under 45 minutes.
I used the same screen on Wavestation AD where the problem was different
- I think somebody mentioned limited space behind the screen on
Wavestation A/D.the solution is to use solderable 20 pin connector on
the ribbon cable. Again you need to find the right source for the +5V,
and in case you want the contrast control to work properly you need to
ad a 10K resistor to the top end of the contrast pot. This is not
necessary, and is not straightforward to do, but it protects the screen.
With K5000 it was similar. I still didn't have time to do the upgrade to
K5m, but it is next in line.
I wouldn't recommend you doing it if it is your first electronics
project. I would say Intermediate level and a professional soldering
iron fith fine tip are a requirement.
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