Reconditioned CRT suppliers in UK?

[Morse]

I used to use Vista in Co Durham, but apparently they are no more. I have a
beautiful 32" Toshiba widescreen Dolby Digital TV here needs a CRT (for the
second time!) and will sadly end up in a landfill unless I can find a tube
for it.

Does anyone know any businesses, preferably in the NE or even Northern
England, who still do reguns?
Hell, I'd rather give it away for bits than it go to a landfill, the only
other failed component is, I suspect, a video amp IC on the CRT base due to
flashover. I haven't had time to assess it myself as it was a
warranty/insurance job and they've written it off.

Thanks

Morse

 

[[email protected]]

I used to use Vista in Co Durham, but apparently they are no more. I have a
beautiful 32" Toshiba widescreen Dolby Digital TV here needs a CRT (for the
second time!) and will sadly end up in a landfill unless I can find a tube
for it.

Does anyone know any businesses, preferably in the NE or even Northern
England, who still do reguns?
Hell, I'd rather give it away for bits than it go to a landfill, the only
other failed component is, I suspect, a video amp IC on the CRT base due to
flashover. I haven't had time to assess it myself as it was a
warranty/insurance job and they've written it off.

Thanks

Morse

Cant help with that, but if you want to try other stuff on the tube
this is the place to ask. Whats the tube fault, eht arcing?


NT

 

[Morse]

Cant help with that, but if you want to try other stuff on the tube
this is the place to ask. Whats the tube fault, eht arcing?


NT

Hi, thanks for our reply.

The TV is already on its second CRT, a regun. The original CRT failed
gradually as the blue crept up over time. The regun was fine for years then
suddenly seemed to darken quite a bit. It stayed like that for months then
the dreaded flashover / intermittant grid short started. The engineer
mentioned that this model (32MW7DB) is known to have a short CRT life.

I'm unsure whether it would be worth chancing a tube hack as I'd have to
replace the blown IC and possibly other components to get it working, with a
strong possibility that it would happen again. I'm certainly open to your
suggestions though. It does switch on, and though the screen is blank, it
does show a flash of life at shutdown with a collapsing white raster.
There's no sound at all, which the engineer thinks is down to the faulty IC
on the CRT base holding a rail down.

Morse

 

[[email protected]]

Hi, thanks for our reply.

The TV is already on its second CRT, a regun. The original CRT failed
gradually as the blue crept up over time.

If you mean the emission fell thats very fixable, and not with rejuve.
Worst set I ever did had emission so bad nothing could be seen on
screen, even that one worked afterwards.

The regun was fine for years then
suddenly seemed to darken quite a bit. It stayed like that for months then
the dreaded flashover / intermittant grid short started. The engineer
mentioned that this model (32MW7DB) is known to have a short CRT life.

I'm unsure whether it would be worth chancing a tube hack as I'd have to
replace the blown IC and possibly other components to get it working, with a
strong possibility that it would happen again. I'm certainly open to your
suggestions though. It does switch on, and though the screen is blank, it
does show a flash of life at shutdown with a collapsing white raster.
There's no sound at all, which the engineer thinks is down to the faulty IC
on the CRT base holding a rail down.

Morse

If the old CRT would be used to regun, so you cant do anything that
would really kill it. But you can risk damaging the gun assembly, as
that'll be replaced anyway.

You probably know all this already, but I dont know you so I'll cover
the ground in case.


Have you tested the crt flashover voltages between the various grids to
find one thats close to operating voltage? If you find one that is, you
may be able to nuke it with a big fat cap, or a rejuve on short removal
mode, tapping the neck while doing it.

Its bad that flashover kills things, but you can test crt flashover
voltage after trying to de-short it, and only reuse it if you're
confident in the result.

I dont have any magic suggestions for shorts, other than repeatedly
hitting it with a cap while pinging the neck in the hope that a jolt
clears it. Since it'll get a new gun assy, you can hit it with as much
capacitance as you want, you've got nowt to lose doing that really.

If its shorting to heater thats easily done by using a transformer
supply for the heater.

Last thought, but once you know what shorts to what, you could likely
put a fairly high resistor in the way for a fixed V electrode. Then if
it arcs again the i will be low, and may be taken up happily by the
video driver, or whatever its shorting to.

I've probably told you nothing new, but who knows. On a set like that
its worth going through the steps to try to clear it. I'm asuming you
know for sure the crt is arcing.

Finally if you get the short and driver fixed, low crt emission is very
fixable, as long as you dont rejuve it. Repair techs love their
rejuves, quick results for a while, but theyre a good way to make tubes
unserviceable in a few months time.


NT

 

[Morse]

If you mean the emission fell thats very fixable, and not with rejuve.
Worst set I ever did had emission so bad nothing could be seen on
screen, even that one worked afterwards.


If the old CRT would be used to regun, so you cant do anything that
would really kill it. But you can risk damaging the gun assembly, as
that'll be replaced anyway.

You probably know all this already, but I dont know you so I'll cover
the ground in case.


Have you tested the crt flashover voltages between the various grids to
find one thats close to operating voltage? If you find one that is, you
may be able to nuke it with a big fat cap, or a rejuve on short removal
mode, tapping the neck while doing it.

Its bad that flashover kills things, but you can test crt flashover
voltage after trying to de-short it, and only reuse it if you're
confident in the result.

I dont have any magic suggestions for shorts, other than repeatedly
hitting it with a cap while pinging the neck in the hope that a jolt
clears it. Since it'll get a new gun assy, you can hit it with as much
capacitance as you want, you've got nowt to lose doing that really.

If its shorting to heater thats easily done by using a transformer
supply for the heater.

Last thought, but once you know what shorts to what, you could likely
put a fairly high resistor in the way for a fixed V electrode. Then if
it arcs again the i will be low, and may be taken up happily by the
video driver, or whatever its shorting to.

I've probably told you nothing new, but who knows. On a set like that
its worth going through the steps to try to clear it. I'm asuming you
know for sure the crt is arcing.

Yes, definitely arcing for some time.

Finally if you get the short and driver fixed, low crt emission is very
fixable, as long as you dont rejuve it. Repair techs love their
rejuves, quick results for a while, but theyre a good way to make tubes
unserviceable in a few months time.


NT

I'll have a look at the TV after Christmas and let you know what I find. I
presume that one of the tricks the tricks you are referring to to up the
emissions is raising the CRT heater voltage?

Morse