toshiba tp48c50 Projection Tv Geometry Problem on red crt

[Michael Kennedy]

My cousin has a Toshiba tp48c50 rear projection tv that has a geometry
problem with the red tube. The picture is good in the center but twards the
edges the red is bent in like the trapazoid adjustment needs to be adjusted.
He called me thinking he needed a new red tube and I told him that it is
probably something else since it isn't dim and it is still in focus.

Does anybody have any ideas where to start with this?

- Mike

 

[[email protected]]

My cousin has a Toshiba tp48c50 rear projection tv that has a geometry
problem with the red tube. The picture is good in the center but twards the
edges the red is bent in like the trapazoid adjustment needs to be adjusted.
He called me thinking he needed a new red tube and I told him that it is
probably something else since it isn't dim and it is still in focus.

Does anybody have any ideas where to start with this?

- Mike

Repair the convergence circuit, probably the red output, and realign
the convergence using a test pattern generator and alignment manual
procedure.

 

[Michael Kennedy]

Does anybody have the service manual for this TV?

- Mike

 

[kip]

Yes we all do.

 

[Michael Kennedy]

Yes we all do.

Okay.. maybe I should restate tha question.. Would anybody be nice enough to
give me the location of this service manual? If you didn' see my parrent
post it is a Toshiba tp48c50.

- Mike

 

[Leonard Caillouet]

You should try Toshiba parts distributors like Tritronics. The manuals are
very reasonable for these sets if it still available. I think this one was
only available on paper and you are unlikely to find it online. I don't
know of any scans of it on any of the sites I use for manuals.

Leonard

 

[Michael Kennedy]

Thanks..
I guess I'll be ordering it.
- Mike

 

[ampdoc]

The C-line sets are very simple, analog convergence, and the Convergence
IC's are on a approx. 5x8 PCB held in with 5 screws located near the center
of the chassis. The board can be removed without disturbing anything else.
Look for the 2 large heatsinks and you'll find it. Be sure to note where
each connector goes as you unplug it, and check the electrolytic caps while
you have the board out. STK392-020 in these if I remember correctly. Replace
them both while you have the board out, cheap insurance. That should fix you
up. The convergence control PCB is in the front of the set, remove the
speaker grille and the plastic cover under it, Conv Ctrl panel is underneath
that. Pushbutton switch turns on the internal crosshatch generator, and the
pots on the board should be labeled. If you have done any pjtv
repair/convergence before this unit should be a cakewalk for you. I never
needed a manual on any of the C or D line sets.

Jammy

 

[Michael Kennedy]

Well I havn't worked on any projection tvs before but it sounds relatively
easy..

- Mike