Hello all...

I have a Smile International CB0913DL, which is a very small color SVGA
computer monitor. The other day, it fell off the top of a mini-tower
computer case that was sitting on a concrete floor. I tried to catch it and
partially succeeded. It hit as softly as one could expect, but I thought I
heard something go "hissssss" when it landed.

It was not powered when this happened. I'm not even sure I really heard a
hissing sound, as the room air conditioning was on and it is loud. Looking
inside the monitor, I can find no sign of damage or broken glass anywhere on
the picture tube. The circuit boards are all tightly in place and everything
looks good there. All the interconnecting cables are in their sockets and I
haven't been able to find anything that was loose or intermittent by
prodding the boards with the power on.

The monitor does turn on normally and the controls respond when pressed.
I've just got no sign of a picture whatsoever, and there isn't even a flash
on the screen when turning the power off. (The monitor always flashed when
turned off before this.) The CRT heater does appear to be running. The only
trace of damage I found was a piece of case plastic that was already
cracked.

My question--if the CRT had lost its vacuum in the fall, wouldn't there have
been a show of sparks and other violent signs of failure when I powered the
monitor? Would the heater in the tube still be functional? I'd have expected
it to burn out quickly.

William

Depending on how the CRT lost its vacuum, and if anything is shorting or not
inside the CRT, will determine if there will be an actual short when putting
the power on to the monitor.

Buy your description, it sounds like the CRT was damaged, and air got
inside. In this case, your monitor is considered to be, "scrapped"!

If you were able to find a CRT and replace it, you may find out the hard way
that something else may also be damaged from the fall. It does not take much
to break pieces in a monitor from being dropped.



--

Jerry G.
======


"William R. Walsh" m
wrote in message news:yTLCi.83765$Fc.59883@attbi_s21...
Hello all...

I have a Smile International CB0913DL, which is a very small color SVGA
computer monitor. The other day, it fell off the top of a mini-tower
computer case that was sitting on a concrete floor. I tried to catch it and
partially succeeded. It hit as softly as one could expect, but I thought I
heard something go "hissssss" when it landed.

It was not powered when this happened. I'm not even sure I really heard a
hissing sound, as the room air conditioning was on and it is loud. Looking
inside the monitor, I can find no sign of damage or broken glass anywhere on
the picture tube. The circuit boards are all tightly in place and everything
looks good there. All the interconnecting cables are in their sockets and I
haven't been able to find anything that was loose or intermittent by
prodding the boards with the power on.

The monitor does turn on normally and the controls respond when pressed.
I've just got no sign of a picture whatsoever, and there isn't even a flash
on the screen when turning the power off. (The monitor always flashed when
turned off before this.) The CRT heater does appear to be running. The only
trace of damage I found was a piece of case plastic that was already
cracked.

My question--if the CRT had lost its vacuum in the fall, wouldn't there have
been a show of sparks and other violent signs of failure when I powered the
monitor? Would the heater in the tube still be functional? I'd have expected
it to burn out quickly.

William

Hi!

Depending on how the CRT lost its vacuum, and if anything is shorting
or not inside the CRT, will determine if there will be an actual short
when putting the power on to the monitor.

That's good to know.

Buy your description, it sounds like the CRT was damaged, and air got
inside. In this case, your monitor is considered to be, "scrapped"!

Ah well. I didn't have much in it, that's for sure. It's actually a very
tiny display, used in applications like POS terminals or similar. To my
surprise it would sync perfectly at 800x600 without issue. It had a good
picture, but the screen burn was terrible. I could still read the log-in
screen text of whatever kind of a system it had been attached to.

At the time, I could have bought a whole trailer of them for pennies on the
dollar. I just didn't believe the guys selling them when they said the
monitors were color. Now I wish I had--these seem to be somewhat hard to
find. :-( Of course, none of them were pretty. All of them had screen burn
and most looked like they'd been used in a basketball game, including this
one. I guess it just finally had enough.

Curiously enough, the electronics all seem to be *fine*. I've got high
voltage, the CRT heater is running, the energy saver LED will come on after
the computer should turn off the screen, and all the controls respond by
turning on the LEDs in their buttons when pushed. Perhaps even more
curious--this monitor does not have OSD (it was made in 1995) but it does
have a dedicated board for the control pushbuttons that uses an 8051
microcontroller in a socket. That seems like a lot of "horsepower" for such
a simple task.

William

"William R. Walsh" m
wrote in message news:7pNCi.83815$Fc.55515@attbi_s21...
Hi!

Depending on how the CRT lost its vacuum, and if anything is shorting
or not inside the CRT, will determine if there will be an actual short
when putting the power on to the monitor.

That's good to know.

Buy your description, it sounds like the CRT was damaged, and air got
inside. In this case, your monitor is considered to be, "scrapped"!

Ah well. I didn't have much in it, that's for sure. It's actually a very
tiny display, used in applications like POS terminals or similar. To my
surprise it would sync perfectly at 800x600 without issue. It had a good
picture, but the screen burn was terrible. I could still read the log-in
screen text of whatever kind of a system it had been attached to.

At the time, I could have bought a whole trailer of them for pennies on
the dollar. I just didn't believe the guys selling them when they said the
monitors were color. Now I wish I had--these seem to be somewhat hard to
find. :-( Of course, none of them were pretty. All of them had screen burn
and most looked like they'd been used in a basketball game, including this
one. I guess it just finally had enough.

Curiously enough, the electronics all seem to be *fine*. I've got high
voltage, the CRT heater is running, the energy saver LED will come on
after the computer should turn off the screen, and all the controls
respond by turning on the LEDs in their buttons when pushed. Perhaps even
more curious--this monitor does not have OSD (it was made in 1995) but it
does have a dedicated board for the control pushbuttons that uses an 8051
microcontroller in a socket. That seems like a lot of "horsepower" for
such a simple task.

William

I have *never* seen a CRT that has lost its vacuum, continue to have a
visibly functional heater. As you surmise, it is normal for it to burn out
immediately. Likewise, it is common to see fireworks in the CRT neck,
particularly with small ones where the inter-electrode gaps are small.
Somewhere on the CRT neck, you might be able to see the gettering flash
deposit which, if the CRT has taken air, will be white rather than shiny
brown. However, sometimes, the getter element hangs down inside the bowl, so
you can't see the deposit. A few voltage checks at the A1, grid, focus anode
and cathode pins, should tell you the story of why there is no display

Arfa

"Jerry G." writes:

Depending on how the CRT lost its vacuum, and if anything is shorting or not
inside the CRT, will determine if there will be an actual short when putting
the power on to the monitor.

Buy your description, it sounds like the CRT was damaged, and air got
inside. In this case, your monitor is considered to be, "scrapped"!

If you were able to find a CRT and replace it, you may find out the hard way
that something else may also be damaged from the fall. It does not take much
to break pieces in a monitor from being dropped.



--

Jerry G.
======


"William R. Walsh" m
wrote in message news:yTLCi.83765$Fc.59883@attbi_s21...
Hello all...

I have a Smile International CB0913DL, which is a very small color SVGA
computer monitor. The other day, it fell off the top of a mini-tower
computer case that was sitting on a concrete floor. I tried to catch it and
partially succeeded. It hit as softly as one could expect, but I thought I
heard something go "hissssss" when it landed.

It was not powered when this happened. I'm not even sure I really heard a
hissing sound, as the room air conditioning was on and it is loud. Looking
inside the monitor, I can find no sign of damage or broken glass anywhere on
the picture tube. The circuit boards are all tightly in place and everything
looks good there. All the interconnecting cables are in their sockets and I
haven't been able to find anything that was loose or intermittent by
prodding the boards with the power on.

The monitor does turn on normally and the controls respond when pressed.
I've just got no sign of a picture whatsoever, and there isn't even a flash
on the screen when turning the power off. (The monitor always flashed when
turned off before this.) The CRT heater does appear to be running. The only
trace of damage I found was a piece of case plastic that was already
cracked.

My question--if the CRT had lost its vacuum in the fall, wouldn't there have
been a show of sparks and other violent signs of failure when I powered the
monitor? Would the heater in the tube still be functional? I'd have expected
it to burn out quickly.

Check for the getter flash inside the CRT neck. There should be an area
of likely shiny metallic coating somewhere inside the glass envelope and
it may be visible near the base. If it is present, the vacuum is intact.
If there is as area of white or red or brown, then it's broken.

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