I would like to share this great tip with all you great helpfull Tech's
out there! This is only for Technicians who really know there way
around the inside of a T.V.! Please don't just anyone try this!! If you
don't have a proper CRT rejuvinating set, this will be a great fix, for
an otherwise lost cause.

Sony 1 K problems, that is T.V.'s with the red, or green, or blue
having too low, or high of an emission to get a raster due to the
"blanking circuit", can be solved with an odd, & somewhat dangerous
technique! With the set off, unsolder each cathode on the CRT board,
then momentarily bridge the gap of each gun, one at a time, to see how
much emission there is. You will have to raise the G 2 pot to get a bit
of raster in a darkened room! Next solder the two good cathodes
(usually only one is out of gain specs), back, leaving the bad one. Now
this is where it gets dangerous!!! While the set is off remove the
focus line from the CRT socket ( 5000 volts), & while the set is
running, momentarily make contact with the unsoldered leg of the bad
gun. Do this with caution, & at least five times. It will try to arc,
but just keep a steady hand, & keep the wire with a good insulated tool
at the unsoldered leg only. Now, while the set is off, unhook the G 2
wire, & set it to about 200 volts DC unloaded, & charge a 100 uf
capacitor @ 250 volts. Do this two, or three times, then discharge it
to the unsoldered gun, while the set is runing. Do this charging, &
discharging to the gun at least five times! At this point, you should
see the bad gun get brighter, & brighter. I have done quite a lot of
experimenting, & this will save a lot of those Sony CRT's, that would
otherwise be toast. Grey scale comes back to within a close enough
spec, to make the customer happy. Just don't give a long warranty. Hope
this helps you all out. Take care, Dani.

Tube kicking is a last resort. I'd never give ANY warranty
and make sure a customer understands this before even
attempting it as the process can also kill a half dead CRT.

What you are doing is causing an arc from the cathode to the control grid.
This will temporarily clean off the cathode. A CRT renouvinator does
basically the same thing, but in a more sophisticated fashion, where it can
also check the other grids for leaks, and also measure the tube's emission.

By arcing the focus supply back across the CRT guns, I hope you don't one
day blow the hell out of the horizontal output stage. Then you will be
spending a lot of time and money on the set to fix it back.

--

JANA
_____


"Dani" wrote in message
ups.com...
I would like to share this great tip with all you great helpfull Tech's
out there! This is only for Technicians who really know there way
around the inside of a T.V.! Please don't just anyone try this!! If you
don't have a proper CRT rejuvinating set, this will be a great fix, for
an otherwise lost cause.

Sony 1 K problems, that is T.V.'s with the red, or green, or blue
having too low, or high of an emission to get a raster due to the
"blanking circuit", can be solved with an odd, & somewhat dangerous
technique! With the set off, unsolder each cathode on the CRT board,
then momentarily bridge the gap of each gun, one at a time, to see how
much emission there is. You will have to raise the G 2 pot to get a bit
of raster in a darkened room! Next solder the two good cathodes
(usually only one is out of gain specs), back, leaving the bad one. Now
this is where it gets dangerous!!! While the set is off remove the
focus line from the CRT socket ( 5000 volts), & while the set is
running, momentarily make contact with the unsoldered leg of the bad
gun. Do this with caution, & at least five times. It will try to arc,
but just keep a steady hand, & keep the wire with a good insulated tool
at the unsoldered leg only. Now, while the set is off, unhook the G 2
wire, & set it to about 200 volts DC unloaded, & charge a 100 uf
capacitor @ 250 volts. Do this two, or three times, then discharge it
to the unsoldered gun, while the set is runing. Do this charging, &
discharging to the gun at least five times! At this point, you should
see the bad gun get brighter, & brighter. I have done quite a lot of
experimenting, & this will save a lot of those Sony CRT's, that would
otherwise be toast. Grey scale comes back to within a close enough
spec, to make the customer happy. Just don't give a long warranty. Hope
this helps you all out. Take care, Dani.

JANA wrote:
What you are doing is causing an arc from the cathode to the control grid.
This will temporarily clean off the cathode. A CRT renouvinator does
basically the same thing, but in a more sophisticated fashion, where it can
also check the other grids for leaks, and also measure the tube's emission.

By arcing the focus supply back across the CRT guns, I hope you don't one
day blow the hell out of the horizontal output stage. Then you will be
spending a lot of time and money on the set to fix it back.



Normally I'd agree, though if the CRT is otherwise shot, who cares?

Isn't it easier and safer with a CRT rejuvenator?


--
==========================
Jeff Stielau
Shoreline Electronics Repair
344 East Main Street
Clinton,CT 06413
860-399-1861
860-664-3535 (fax)

========================

"Dani" wrote in message
ups.com...
I would like to share this great tip with all you great helpfull Tech's
out there! This is only for Technicians who really know there way
around the inside of a T.V.! Please don't just anyone try this!! If you
don't have a proper CRT rejuvinating set, this will be a great fix, for
an otherwise lost cause.

Sony 1 K problems, that is T.V.'s with the red, or green, or blue
having too low, or high of an emission to get a raster due to the
"blanking circuit", can be solved with an odd, & somewhat dangerous
technique! With the set off, unsolder each cathode on the CRT board,
then momentarily bridge the gap of each gun, one at a time, to see how
much emission there is. You will have to raise the G 2 pot to get a bit
of raster in a darkened room! Next solder the two good cathodes
(usually only one is out of gain specs), back, leaving the bad one. Now
this is where it gets dangerous!!! While the set is off remove the
focus line from the CRT socket ( 5000 volts), & while the set is
running, momentarily make contact with the unsoldered leg of the bad
gun. Do this with caution, & at least five times. It will try to arc,
but just keep a steady hand, & keep the wire with a good insulated tool
at the unsoldered leg only. Now, while the set is off, unhook the G 2
wire, & set it to about 200 volts DC unloaded, & charge a 100 uf
capacitor @ 250 volts. Do this two, or three times, then discharge it
to the unsoldered gun, while the set is runing. Do this charging, &
discharging to the gun at least five times! At this point, you should
see the bad gun get brighter, & brighter. I have done quite a lot of
experimenting, & this will save a lot of those Sony CRT's, that would
otherwise be toast. Grey scale comes back to within a close enough
spec, to make the customer happy. Just don't give a long warranty. Hope
this helps you all out. Take care, Dani.