Hey everyone, Aaron here from Gough Custom, and today a really quick video because I
need to replace Milly's CRT screen. So this screen, as far as I know is the original one
that came with the machine, which means that it's about 25 years old, which is
honestly pretty good. And it failed the other day while I was using it, and the failure was
actually kind of satisfying because it was very mechanical, the screen started moving around and
flickering up and down and then it just blinked out and I couldn't get it to come back on. So
today I'm going to replace it with an LCD monitor and I thought you might like to see the process!
Okay, so here we have the back of the CRT monitor, and then over here we have
the interfaces for the machine to talk to the controls on the front of the pendant.
So here we have the controls for feed and spindle override, e-stop all that kind of stuff,
and then down here we have the keyboard interface. One thing that's worth noting
when you're dealing with a CRT monitor like this is that they can retain substantial high voltage,
even after they've been disconnected for days or weeks. Most of the time,
they should have a discharge resistor across the main capacitors, but that doesn't really
matter just don't go sticking your fingers in unless you're sure that it's all discharged.
So while having a poke around in here, I think I can see the cause of the screen failure... You
can see right here, there's a burnt connector and it's right next to this one, of the the
big capacitors and there's actually gel on the outside of that capacitor, which means that it
may have vented on the bottom or there might be some other component behind there that's vented.
That's probably what killed the screen, I don't see any other obvious failures. Even though I
can see the likely cause of the failure, I think I still want to replace the screen anyway, because I
have the new screen on hand and the LCD screens are just much nicer to use much easier to read
the text on and much more stable. So we're going to go ahead and pull the CRT out and replace it.
Before I start poking my fingers around in here, I'm just going to double check that there are no
voltages still on this board. So I'm just going between a grounded point on the chassis
and then I've got the positive probe of the multimeter on the high voltage lines for the
CRT, this should tell me pretty quick if there are any capacitors still holding charge in here.
Looks like we're good!
So this is the BNC connection that actually brings in the video signal,
this is an old school coaxial connector that brings in an analog video signal from the control
computer. So one of the challenges in finding a replacement for this screen is that you have
to find one that has a BNC connection, or has a different connection that's easy to convert it to.
Here we've got the main power connector... I didn't say this before, but obviously
the mains power to the machine is currently turned off! Don't work on a machine like this,
especially high voltage components, when there's power on, that's a really bad idea.
So here we have the whole CRT module and I honestly think these things are super cool.
Despite being obviously incredibly outdated,
the idea of displaying an image by shooting a beam of electrons at a phosphor coated screen is just
mind boggling to me, it's crazy that this was the simple technology at one point you know.
Off this, I'm going to salvage the power connector so that I can use that for the
new screen and power supply, and everything else is trash. And here is the lovely new LCD monitor,
I actually bought this direct from China on AliExpress. There are a couple of companies
that sell Fadal LCD replacement monitors, but they're like 800 bucks us or more, and they're
basically the exact same thing as this, which cost me $120 USD! I'll put a link to this in the video
description if anyone needs a Fadal replacement or just a nice little industrial monitor.
I've got one of these in my other machine and it's been working great,
so I was super happy to get another one. So one of the really nice things about this
monitor are, a couple of really nice things, one it has no logos or controls on the front so
it blends into the machine really nicely once it's once it's fitted,
and then second, it actually has a BNC connection on it directly. So this literally
just plugs right into the machine and then it works perfectly with no adapters, no nothing!
For power, it comes with this little wall-wart power supply. We're not going to use this because
it would be very awkward to safely fit this into the machine, so instead I bought this little guy
off Digi-Key, this is a 36 watt MeanWell 12 volt power supply. It's a nice little switchmode power
supply, and we'll actually be able to mount this on the back of the monitor on the VESA mount.
Okay, so the very first thing we're going to do is strip some wires on this so that we can attach it
right, and now we need to cut the connector off this guy so that we can connect power from the
screen to the power supply. Now, usually with these barrel jacks, the outside is the negative,
but there's actually a really quick way to double check which I'll show you. So if you have a look
right here on the back of the AC adapter, this little symbol here actually shows you
the polarity of the barrel jack. So it's saying negative it's the outside, positive is the inside.
The cable itself on the plug is marked with a stripe on what should be the negative lead, but
we're going to double check that with continuity on the multimeter. Yeah, so I've just established
that there's continuity between the striped conductor and the outside of the barrel jack.
So there you go, we've got a nice little modular wiring harness here for the screen,
we can just plug the DC jack in right there, and then I'm actually just going
to double sided tape this onto the back of the monitor, it'll be good enough.
All right, and to keep the cables nice and tidy just chuck a little zip tie holder on. Okay,
so before we plug it in, let's just do a quick double check, I always do this. So we've got black
to line, white to neutral, green to ground. We've got the striped conductor from the barrel jack
going to the negative and we've got the plane conductor from the barrel jack into the positive.
Get that plugged in, do a quick tug test on each of these guys,
make sure they're firmly seated. And we're good!
Okay, so back at the pendant, we have this cross brace here, this piece of painted sheet metal.
The only reason that this is here is to provide a mounting place for the CRT,
and we don't need it anymore, and it's really in the way. So I'm going to go through and
remove that, and then I'm also going to remove the plastic bezel on the front of the pendant.
So handy tip: I've got a hex head bolt here that's pretty stripped out, I can't get this allen key to
turn it. So what you can do to get a hold of that is to grab a Torx bit, that's just the right size
to fit in there, maybe a little bit larger, you want it to be a quite a tight fit, and
that will create quite a strong grip that allow you to get hold of that stuck bolt. Like that.
So it turns out that the plug that this connects to in the machine actually doesn't have a ground
connection, so I don't even know why this is here like this actually doesn't connect to anything
in the machine. So I'm going to pull this wire out so that we can connect the redundant ground
in there to this little power supply. Then the final thing that we need to do is make a way
to actually mount this into the machine. The monitor is the exact right size for the hole
that the CRT monitor came out of, but it doesn't have any mounting locations that we can use. So
these are little mounting bars that came with the monitor,
what I'm going to do is drill some holes through this to align with these little M2 holes here,
and then this will form like a little clamping bracket on either side.
I'm just gonna take this ground wire and run it up around here and to the power supply.
Look at that it's beautiful! So it's time to button her up and see if she works.
So right now it's on the wrong input, which means that it won't show anything... So
you have to chuck some batteries in the little remote that came with this guy.
So look at this, we're back up and running! It's beautiful! It's amazing how quick it is
to fit this particular screen into a Fadal even though it's not a drop in replacement,
this was two hours start to finish, which in my mind is ridiculous for something that's
not meant to be a drop in monitor, it's really really good, so I am super happy.
So I just wanted to take a minute and say thank you to my Patrons. Having Patrons
for my YouTube channel really helps allow me to make videos like this one where I get to share
my knowledge. If you learned something from this video and you'd like to become a Patron,
the link is underneath the video. I hope all of you enjoyed this process and getting
to see inside one of these awesome old machines. I'll be seeing you again soon!