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60" RCA w/CTC169 Chassis Convergence Setup

G

Grauwulf

Jan 1, 1970
0
Hey all!
Hopefully someone can give me a little guidance on this. I recently
picked up a 60" RCA rear projection TV on the cheap, dead. It had a
coolant leak on the green tube and was causing the anode to arc. I
repaired the coolant leak and the messed up anode lead so now the unit
powers on, but the convergence is totally messed up now. I expected it
to be a little off, but nothing like it is. Originally I was able to
get the crosshair all lined up in the center of the screen from the
user menu, but things were still out of alignment around the edges of
the screen. So I was tweaking the other controls behind the speaker
grille and I have made it worse. So I talked to a service center and
they are telling me it can take up to 8 hours to set up the
convergence and that the HV arcing has probably damaged the convergence
chip.

What is everyone's thoughts on this?

Thanks!
James
 
M

Meat Plow

Jan 1, 1970
0
Hey all!
Hopefully someone can give me a little guidance on this. I recently
picked up a 60" RCA rear projection TV on the cheap, dead. It had a
coolant leak on the green tube and was causing the anode to arc. I
repaired the coolant leak and the messed up anode lead so now the unit
powers on, but the convergence is totally messed up now. I expected it
to be a little off, but nothing like it is. Originally I was able to
get the crosshair all lined up in the center of the screen from the
user menu, but things were still out of alignment around the edges of
the screen. So I was tweaking the other controls behind the speaker
grille and I have made it worse. So I talked to a service center and
they are telling me it can take up to 8 hours to set up the
convergence and that the HV arcing has probably damaged the convergence
chip.

What is everyone's thoughts on this?

Thanks!
James

Change the convergence chips. They aren't that expensive. Buy a service
manual and go through the static and dynamic convergence steps.
 
G

Grauwulf

Jan 1, 1970
0
I am a little dubious only because I have a bit of experience working
on CRT based arcade monitors (basicly CRT TV's minus the tuner section)
and I have had numerous flybacks blow and send HV to ground via the
frame of the monitor and I have yet to experience a component failure
because of it. However, this is the first projection TV I have worked
 
Grauwulf said:
Hey all!
Hopefully someone can give me a little guidance on this. I recently
picked up a 60" RCA rear projection TV on the cheap, dead. It had a
coolant leak on the green tube and was causing the anode to arc. I
repaired the coolant leak and the messed up anode lead so now the unit
powers on, but the convergence is totally messed up now. I expected it
to be a little off, but nothing like it is. Originally I was able to
get the crosshair all lined up in the center of the screen from the
user menu, but things were still out of alignment around the edges of
the screen. So I was tweaking the other controls behind the speaker
grille and I have made it worse. So I talked to a service center and
they are telling me it can take up to 8 hours to set up the
convergence and that the HV arcing has probably damaged the convergence
chip.

What is everyone's thoughts on this?

Thanks!
James

It is possible that HV arcing may have damaged something, it is not
that common in that chassis unless you left the HV lead on the
convergence output board and tried to power the set up.

The service center does not appear to know your set, or you did not
provide them with enough details on the chassis number. That set does
not have convergence output ICs but discrete transistor outputs. The
waveform generator and D/A converter for the convergence adjustments
are all on the front pcb. If you can adjust each colors geometry and
dc offset, then it is probable that someone previously also messed with
the controls.

A full geometry and convergence adjustment on that set may take several
hours to complete from scratch.
 
G

Grauwulf

Jan 1, 1970
0
All of the controls for convergence seem to function as advertised, so
I am doubtful that anything is damaged. When I was speaking to the
repair shop I gave them the chassis model number. He has a tech on
staff that he says is familiar with the RCA chassis. So I guess we'll
go from there. Unfortunatly there are not too many TV reapair shops in
the area anymore, but this guy has been in business since 1972, so he
or his staff must know something. Thankfully the lightbox is easily
removable from this set, so I can just take him the lightbox to do the
majority of the convergence work instead of paying for a housecall.
 
Grauwulf said:
Hey all!
Hopefully someone can give me a little guidance on this. I recently
picked up a 60" RCA rear projection TV on the cheap, dead. It had a
coolant leak on the green tube and was causing the anode to arc. I
repaired the coolant leak and the messed up anode lead so now the unit
powers on, but the convergence is totally messed up now. I expected it
to be a little off, but nothing like it is. Originally I was able to
get the crosshair all lined up in the center of the screen from the
user menu, but things were still out of alignment around the edges of
the screen. So I was tweaking the other controls behind the speaker
grille and I have made it worse. So I talked to a service center and
they are telling me it can take up to 8 hours to set up the
convergence and that the HV arcing has probably damaged the convergence
chip.

What is everyone's thoughts on this?

Thanks!
James

What is the chassis # of this set? If it is PTK 195, Carefully remove
PTV AUX Module (one on thr right.Inspect cir bd for Coolant leak,
Espically in aera of Sockets ( the 2 with ribbon connectors) I use
laquer thiner for a cleaning solvent ( It dries fast & Clean) this
fixed one for me a couple of weeks ago Also be sure coolant level is
not too high in tubes. Some of these sets came from Factory over
filled, When they got hot coolant expands. The reason for puke bottle
on your cars radiator. Feel free to contact me if you need more
[email protected]
 
Grauwulf said:
It is a CTC169 Chassis.
Sorry I Missed the chassis # But the coolant could still be the
problem, If leaked on the PTV AUX cir bd. I've seen holes burned all
way through the board, also look for signs on cir bd of over heating.
Pull Aux bd out & check transistors with digital meter ( Aux Bd is NLA)
 
G

Grauwulf

Jan 1, 1970
0
http://www.wolfelectronics.ca/greengrid.jpg
http://www.wolfelectronics.ca/redgrid.jpg
http://www.wolfelectronics.ca/bluegrid.jpg
http://www.wolfelectronics.ca/fubargrid.jpg
http://www.wolfelectronics.ca/panel.jpg

Here are some pictures of what I am dealing with. The green is the only
one that is my concern simply because I know I messed up the blue and
red fiddling with the adjustments. The green seems to be rotated a
little bit clockwise. I'm wondering if it is some inattention on my
part making sure the CRT was square to the lens housing when I was
repairing the coolant leak since the neck magnets don't seem to give me
the adjustments I need to square it up.

Anyone have any suggestions?
 
M

Meat Plow

Jan 1, 1970
0
http://www.wolfelectronics.ca/greengrid.jpg
http://www.wolfelectronics.ca/redgrid.jpg
http://www.wolfelectronics.ca/bluegrid.jpg
http://www.wolfelectronics.ca/fubargrid.jpg
http://www.wolfelectronics.ca/panel.jpg

Here are some pictures of what I am dealing with. The green is the only
one that is my concern simply because I know I messed up the blue and
red fiddling with the adjustments. The green seems to be rotated a
little bit clockwise. I'm wondering if it is some inattention on my
part making sure the CRT was square to the lens housing when I was
repairing the coolant leak since the neck magnets don't seem to give me
the adjustments I need to square it up.

Anyone have any suggestions?

Those pictures indicate to me that the static (mechanical) adjustments
need attention. Do you have service literature available? You will need it.
 
G

Grauwulf

Jan 1, 1970
0
I do not have the service literature. Any suggestions as to where I can
order it from?

Thanks!
James
 

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