I couldn't tell you. In my experience, it *very rare* to have the LCD
itself fail. There have been a rare time or two where the customer
actually broke the LCD. The most common complaint I get with one model of
UT instrument is that the video "is smearing or tearing and the colors
fluctuates". Then I'm not so sure that it is the LCD panel more than it
is the LCD Panel matching up to the given instrument's Main (computer)
board and the 50 MHz FPGA clock that the video circuits run off of. You
change the LCD and the problem is gone, but take the same LCD that was
smearing/tearing and put it in a different model of instrument and it works
absolutely fine.
I haven't actually purchased these 65BLM05 LCD panels in a long, long time
(as I had a small supply to begin with). The number one failure is the
portable instrument gets dropped and one of the two fluorescent tubes get
broken. i cases where the customer thinks the instrument is dead, both
tubes have broken - lol. You do get them where its okay and it just
doesn't look right. then it is DIM tubes. My TDS3032 was looking very
tired that way. When I replaced the DALLAS EEPROM last year (as some of
you on here may have followed), I replaced one the backlight tubes (I don't
remember why anymore, but I couldn't get the other one out, or a new one to
fit in and I just didn't fight it). Replacing even one sad tube with a
bright new one, made the scope look much better and new again.
What I want to try now is using that LED kit to refresh these displays.
$130 per kit, hmmm, wow, but I better make the investment to try it. I
would double the part acquisition cost if it works and get my money back
and the customer would get his instrument back with a bright fresh looking
display and an instrument that could draw 800ma, or so, less battery
current, extending the operation life of the instrument. I only hesitate
because these instruments that I work on are used 40-60 hours per week and
I don't know if the LEDs or the LED Drivers are reliable. So, I have to
invest the $130 myself and put that LED kit in a test instrument I have and
run it for a few months straight.
From that video I linked in a message or two ago, I think that kit would
really brighten up a TDS3000 Series scope and make it look new again (sans
the yellowing front bezel plastic). Then again, the B/L tubes probably
will last another 20 years. Cam anyone see a currently 20 year old TDS3032
still in use 20 years from now? lol If I'm still here, I don't know if I
will be interested in using it.
Dave
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On Thu, Nov 7, 2019 at 10:00 PM Tom B <tbryan@...> wrote: Hi Dave,
If you look at this video it
shows a part number on the back of the display as 65BLM04 and on the
front of the display the tag says NL6448BC20-08. If you search each of
these part numbers on ebay, the price is very different when they are
actually the same part. The cheapest price I could find for the
65BLM05 is $158.74 (used), while the cheapest price for the
NL6448BC20-08 is $88 for a new part. These appear to be exactly the
same part. Any idea if there is any difference?
Tom
On 11/7/2019 2:28 PM, David Kuhn wrote:
;!b9GWhakWANQ!wbXzExaWmEY10yA6ddr1j7dzMVPNV7j4iMLI9u6paEFuQ5tXhS6mqOV8S_HN$
;!b9GWhakWANQ!wbXzExaWmEY10yA6ddr1j7dzMVPNV7j4iMLI9u6paEFuQ5tXhS6mqCtAAjYv$
Looks like a perfect solution for the NEC on the TDS3000 series and in
the
NEC 65BLM05 Display (virtually the same display as the one TEK uses) in the
instruments I do a lot of work on.
Unlike the video, I would not remove the paper exposing the glue when
installing the strips. I don't want those LED strips permanently in my
LCDs in case they fail.
Dave
On Wed, Nov 6, 2019 at 11:40 PM Harvey White <madyn@...> wrote:
If you have some familiarity with LCD displays, or CRT displays with
separate drive, then *if* the signals are good, you should be able to
recognize them. If they're bad, however, well.... Let alone which test
point is what......
Harvey
On 11/6/2019 10:08 PM, Tom B wrote:
Hello All,
I am just catching up on this thread.
There is a youtube video on replacing the CCFLs with LEDs here
;!b9GWhakWANQ!wbXzExaWmEY10yA6ddr1j7dzMVPNV7j4iMLI9u6paEFuQ5tXhS6mqLLaLTRs$
The part number for the TDS3000 (no letter) display is listed in the
service manual as an NEC NL6448AC20¨C06. These displays are available
on ebay and other places for about $60US. I think the part number
for the B model is NL6448BC20-08, but I am not 100% sure of that.
These displays are running about $80-$100US. The only difference I can
find in the in the datasheets between NL6448AC20¨C06 and the
NL6448BC20-08 is that the -08 model has higher luminance.
Can anyone verify the part number on the TDS3000B display?
I will check for the for the signals that Harvey mentioned when I have
time. The pins that go to the display are really hard to get to
because of the way this thing is built. There are the test points on
the main board, but the service manual makes no mention of what they
are for.
Tom Bryan
N3AJA
On 11/6/2019 10:58 AM, Harvey White wrote:
This is the first item that came up when searching for CCFL LED
replacements
;!b9GWhakWANQ!1VZO1N_UzGPrK5tvZk-sSIE3W2ulp1zapXqXmDScqYhd9jWmbO6SGjvZhNdA$
no idea if they have anything that will fit.
I have made CCFL replacement strips for some odd displays, the older
Optrex DSTN color displays and the FG0800 8 inch VGA display.
Due to the lack of 12 volts in a battery operated project, all of
them are designed to run the LEDS in parallel, at about 15 ma per
led, about 9 per 4 inch strip. The strips are designed to be
stacked, resulting in parallel operation.
Whether or not the lamps can be reasonably replaced depends on the
manufacturer. In the Optrex displays, remove a screw, swing a shield
aside, and pull out the tube. In the FG0800, it's more involved (and
takes 4 strips), even more if you wanted the side. The silly tube is
a top, left, and bottom assembly.
The replacement should be made to run off the (suspect 12 volts)
supply, and a simple PWM would easily replace the inverter. I'm sure
it varies wildly.
I know there's a market out there, and the more common the display,
perhaps the easier it is to find the LED replacement, or even the
tube itself (which I'd recommend unless you want to go LED).
I went LED because the power consumption in battery operated
equipment goes down by 50 to 75%, and I'm not happy with 1600 volts
running around an experimental setup.
So give these people a try, they seem to be going laptop, so no idea
what else they do.
You might also want to look here:
;!b9GWhakWANQ!1VZO1N_UzGPrK5tvZk-sSIE3W2ulp1zapXqXmDScqYhd9jWmbO6SGtNxwsuf$
10 dollars.
Harvey
On 11/6/2019 10:03 AM, David Kuhn wrote:
" there are commercially
available LED backlight kits to replace the CCFL lamps. "
I would be in your dept if you could point me to an LED replacement
for the
fluorescent tubes in the NEC displays like that are used in the
TDS3000
series (no bloody A, No bloody B or C). I'll get the actual NEC LCD
part
number and reply again later. I wonder if the LED replacement is
made to
run off the fluorescent tube inverter supply? I ask that because
that
supply has software control line to control the brightness. LET is
probably off or on, unless it is designed to run off the inverter or
a
software equivalent inverter is available (retrofitting old
equipment not
designing new stuff).
dave
On Tue, Nov 5, 2019 at 2:31 PM Harvey White <madyn@...>
wrote:
On 11/5/2019 1:59 PM, David Kuhn wrote:
Sorry for the response delay.
I am in Lewistown, PA. How cheap are the displays and where are
you
finding them? I have found the ones, used in the Ultrasonic
instruments I
mentioned, on Alliexpress, and EBAY (haven't ordered any from
either
one),
but I can not find the backlight tubes, which I find is usually the problem
with the displays. The displays may be just slightly different
than in the
TDS3032, but if so, only mechanically. The connectors are the
same, and I
really think the part numbers are the same. It's not a real easy
replacement in those TDS scopes. It looks easy, but it's a pain
in the
butt. Depending on the manufacturer of the display, there are commercially
available LED backlight kits to replace the CCFL lamps.
You may want to buy the TDS3GV on EBAY. I can't use a TDS3032
without one,
but I have written a lot of service software in VBA and VB6 that
automatically sets up the scopes and gets data from them. I can
also
project my TDS3032 to the 32" TV mounted on the wall above it (an
older
Sceptre with VGA input) and that's pretty cool.
Again, if the cables are seated well, I doubt the LCD is bad with
an
all-white display. My thoughts are a main PCB issue. A TSD3GV
could
prove
me wrong. If you find an all white display, then depending on the type of
display
(positive or negative) you'd suspect no signals to it, or improper
signals.
The display is likely to take either 5 or 3.3 volts, recent ones
that I
have take 3.3. Older STN displays can take 5. The white is the
result
of the backlight working, but no active pixels at all (hence no
polarization, etc....).
Like a CRT display, you'll be looking for a horizontal sync (at
perhaps
30 Khz), vertical sync (say 60 or so Hz), a DE (likely at horizontal
rate and active high), and a pixel clock at about 25 or so Mhz.
You'd
also expect supply voltages to be somewhere on the display. If the
timing is right and the voltages are there, then the display ought
to be
showing something. If not, then look at the other pins, they
should be
R,G,B digital signals, either in 565 (for a 16 bit panel) or 666
(for an
18 bit panel). If there's any activity on them, then with the right
sync signals, they ought to be giving something on the display.
Harvey
Dave
On Tue, Oct 29, 2019 at 10:55 PM Tom B <tbryan@...> wrote:
Hi Dave,
I tried the "B Trig" and nothing happened. Displays are fairly
cheap
but I don't want to buy one unless I have to.
Thank you for the offer. I would be a long while before I make
it up
that way.
What town are you in?
Tom
On 10/29/2019 4:52 PM, David Kuhn wrote:
I'm in central, PA, about 3 hours from you if you ever want to
come up and
try it here with one of my VGA/GPIB modules.
Before that. Power it up while holding in the "B TRIG" button
(might be
different on the TDS3014), which on my TDS3032's causes a
RESET. I've had
that fix display issues after replacing the battery NVRAM in in
the
scope.
The display in the TDS3032, is the exact same LCD used in the
GEIT
Phasor
XS and USN60 instruments. I have worked on many. I have never
seen
the
LCD fail on those instrument where it's all white. Typical, if
not
broken,
is smeary displays that lines seems to go out of sync. Dim, of
course with
broken backlight tubes.
Dave
On Mon, Oct 28, 2019 at 10:50 PM Tom B <tbryan@...> wrote:
Hi Rich (?),
Thanks. I am located in Maryland near Washington DC.
If anyone in the Washington DC area has a TDS3GV that I could
come
over
and quickly test my scope with, I would appreciate it.
Tom Bryan
N3AJA
On 10/28/2019 10:29 AM, Oz-in-DFW wrote:
I'd still remove and reseat both ends.
Where are you in the world? I have a VGA/serial/GPIB card in
my 3014 that we might be able to mate with your scope briefly.
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