CRT Red screen

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L

L

NEC MultiSync E950 sometimes the screen turns red. A very slight tape
on top of cabinet makes picture return to normal. Is that (I am asking
for opinions here) the guns in the CRT or circuitry in the E950.
Anyone know were to get a circuit diagram for the E950.
Thanks in advance.
 
L said:
NEC MultiSync E950 sometimes the screen turns red. A very slight tape
on top of cabinet makes picture return to normal. Is that (I am asking
for opinions here) the guns in the CRT or circuitry in the E950.
Anyone know were to get a circuit diagram for the E950.
Thanks in advance.

Try this:
http://www.nec-display-solutions.co...ish.pdf#search="NEC Multisync E950 schematic"


Ppg. 1-16 are in English. While I didn't see a schematic diagram, it
does have a troubleshooting page.

Christopher
 
The fault you mentioned could also be due to faulty connecions in the
signal lead plug or socket in the monitor.

Dry joints on the tube base panel could also be the cause, solder is
only lead and tin and eventually cracks around the joint as it ages,
heats up and then cools down over time, the connection then will
become resistive and then intermittent and over time eventually open
circuit, these are known as dry joints.

Internal shorts in the tube could produce a coloured raster or
picture, either red, green or blue and sometimes faulty connections
inside the tube can also be the problem, obviously in this case the
remedy is a new tube.

If ever inspecting disconnect the monitor from the mains and look for
grey looking soldered joints, these are easily spotted as they may
look cracked.. a good solder connection should look silver and
shiney.

With computer monitors sometimes the tube base panel is hidden behind
a screening plate and sometimes a pain to get to.

Davy
 
Davy said:
The fault you mentioned could also be due to faulty
connecions in the signal lead plug or socket in the monitor.
Dry joints on the tube base panel could also be the cause,
Yes.

solder is only lead and tin and eventually cracks around the
joint as it ages, heats up and then cools down over time,

Wrong, dry joints arent inevitable.
the connection then will become resistive and then intermittent
and over time eventually open circuit, these are known as dry joints.
Internal shorts in the tube could produce a
coloured raster or picture, either red, green or blue

Possible, but much less likely than faults outside the tube.
and sometimes faulty connections inside
the tube can also be the problem,
Ditto.

obviously in this case the remedy is a new tube.
If ever inspecting disconnect the monitor from the mains and look for
grey looking soldered joints, these are easily spotted as they may
look cracked.. a good solder connection should look silver and shiney.

There's plenty of dry joints that arent visible
even when you know which joint has failed.
 
NEC MultiSync E950 sometimes the screen turns red. A very slight tape
on top of cabinet makes picture return to normal. Is that (I am asking
for opinions here) the guns in the CRT or circuitry in the E950.
Anyone know were to get a circuit diagram for the E950.
Thanks in advance.

Have had a number of CRT units pass through my hands (a number of
years ago) with this type of defect. The pins carry signals which
determine colour input. If you are lucky a check of the pins in the
connecting socket may reveal one is slightly bent. Using something,
such as a small screwdriver, to slightly move the pins, may correct
the colour loss.

KM
 
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