Hello! I have a 20 million serial# TS-940S (Mint!).
The Sub-Display currently has two problems - I think they are
unrelated - but this is a guess.

1. Ever since I had the radio (4 years ago), the LCD display fades in
and out. The actual black liquid crystal letters fade away almost
completely and then fade back in, randomly. Not related to activating
any function of the radio or temperature. Its almost the effect you
get when viewing the display from an off-angle how the characters
displayed tend to get dimmer. However - I am viewing it straight on
and it changes in intensity. I think there is a contrast adjustment
and its as if that is not holding its value. Need some advice on this
one. I am NOT referring to the light bulbs here - they are both fine
and hold a constant lux. The Kenwood "Erratic LCD" TSB doesn't seem to
fit my problem and I think my 20 million serial number isn't included.

2. The LCD display itself is now (recent) showing just "stars" (all
LCD blocks are lit). None of the display buttons change
what is displayed. I have read elsewhere that this could be from
the internal battery going dead.

I know I should replace the internal battery for starters, but I think
the
fading display is another issue that I would like to troubleshoot
before I order just a battery.

Any and all advice appreciated!

-Scott, WU2X

wrote in message
ups.com...
Hello! I have a 20 million serial# TS-940S (Mint!).
The Sub-Display currently has two problems - I think they are
unrelated - but this is a guess.

1. Ever since I had the radio (4 years ago), the LCD display fades in
and out. The actual black liquid crystal letters fade away almost
completely and then fade back in, randomly. Not related to activating
any function of the radio or temperature. Its almost the effect you
get when viewing the display from an off-angle how the characters
displayed tend to get dimmer. However - I am viewing it straight on
and it changes in intensity. I think there is a contrast adjustment
and its as if that is not holding its value. Need some advice on this
one. I am NOT referring to the light bulbs here - they are both fine
and hold a constant lux. The Kenwood "Erratic LCD" TSB doesn't seem to
fit my problem and I think my 20 million serial number isn't included.

2. The LCD display itself is now (recent) showing just "stars" (all
LCD blocks are lit). None of the display buttons change
what is displayed. I have read elsewhere that this could be from
the internal battery going dead.

I know I should replace the internal battery for starters, but I think
the
fading display is another issue that I would like to troubleshoot
before I order just a battery.

Any and all advice appreciated!

-Scott, WU2X


Scott -

As N5IW knows from practical experience -- the main problem with most of the
Kenwood radios (TS-940S and others) built during the late 1980's involved
poor solder technique (quality control during assembly) and possibly the
usage of sub-standard solders.
http://www.qsl.net/n5iw/ts940.html

A thorough re-work of the most accessible boards (those most suspect to
prior owner tampering, poking, wiggling, and plug/unplug) may yield the
greatest results. As you can imagine; this process takes some time.
In summary, N5IW's total repair work on his TS-940S involved:

Correcting and reassembling 2 completely disconnected plug bodies
12 to 14 visually obvious cold-solder connections (complete removal of
solder and resolder with a quality US brand)
30 or so suspected bad connections on various plugs and components
(resistors, capacitors, etc.).

The cure for these intermittent issues is the comprehensive and careful
examination of the multitude of plug connectors and their solder points used
heavily through-out the rigs. This requires modest electronic skills (
soldering, and careful attention to detail - you must have good
discriminating eyes) and can be completed by the most novice technicians or
ham operators.

w9gb