Toshiba Model# CF2044J Chassis# 8900 sparking

[Ian Stirling]

Let me first start out by saying this is a 13 year old set, not to
mention I'm a student, so it's just not very cost effective to have it
professionally repaired. I have replaced C301 and C305 to fix a
vertical drift problem some time back. I also had to later resolder
all joints on the CRT neck board because of cracked solder joints.
Now, there is sparking in the CRT socket sparkgap for the focus wire.
This arcing began probably about 6 months ago, but rarely occoured.

Being in a similar position, I'd first try examining the spark gap surrounds
for carbonisation, and removing any I found.
Followed by a spray of 'damp start', or some other dielectric film spray.
Do ensure that you remove the film from the actual spark gap electrodes.

 

[David]

The two low cost possibilities.
Bad solder connection to the ground connection of the flyback focus/screen
control, remove the old cracked solder and resolder.
Dirt build up in the focus spark gap, give it a good cleaning.

The not so inexpensive possibilities.
Bad capacitors in the main power supply causing a slightly overvoltage
condition, get a good ESR meter and give them a check. If it uses the SMPS
look closely at c840,c841,c863, and c822 and all the others.
Flyback focus control is going bad, flyback will need replaced. Asti
Magnetics is about the least expensive for aftermarket flybacks if they have
it.

David

 

[its you]

Let me first start out by saying this is a 13 year old set, not to
mention I'm a student, so it's just not very cost effective to have it
professionally repaired. I have replaced C301 and C305 to fix a
vertical drift problem some time back. I also had to later resolder
all joints on the CRT neck board because of cracked solder joints.
Now, there is sparking in the CRT socket sparkgap for the focus wire.
This arcing began probably about 6 months ago, but rarely occoured.
It has been becoming more frequent with time, but after the set is
warmed up it essentially disappears. It doesn't occur at every
startup, but startup is when it will generally happen, usually no more
than 2 times. It occurs every time after the CRT has been discharged
(maunally of course). I realize this is probably due to excessive
voltage, but what would cause this? Drifting components? Or could
the CRT just be going bad? Any help is always appreciated, and
thanks in advance, Steve