help needed with broken crt neck pcb

[Arm?nio Pereira]

Hey there! I got a small tv with a broken pcb on the neck of the crt,
the owner took it apart and carelessly broke it... worked fine before
(I wonder why he took it apart...).
I carefully soldered across all contacts with small wires, but now I
obtain only a whiter than white picture with a slightly reduced height
(brightness control totally uneffective)... Could I have accidentaly
damaged any component while soldering, or could it have been caused by
operating the tv with the broken pcb? Where should I start looking
first? Any help would be greatly appreciated!
regards
Arménio Pereira

 

[Jerry G.]

If that is the only place that was disturbed, then the fault has to be where
the work was done. Most likely in the soldering job, some traces are most
likely bridged, or a component that became sensitive from age, was damaged
from the heat of the iron. Going by your description, I would be inclined
to look for something shorted rather than opened.

It is also possible that if something was shorted, there may be come
collateral damage in other parts of the set. This all depends on the
particulars of the design, and the exact nature of the damage.

On the other hand, maybe you fixed the board, and are back to the original
fault. You then have two variables to contend with.

You did not mention the model number, but normally if we had this type of
affair, we would be getting in touch with the manufacture to have a price
and delivery for a new board. I would only do such a repair if the board was
no longer available. When fixing a broken PC board, there can be a lot of
time, and complications involved, such as what you have.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
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"Arm?nio Pereira" <armeniopereira@hotmail.com> wrote in message
news:4fa52a7c.0403250459.1fd6a9aa@posting.google.com...
Hey there! I got a small tv with a broken pcb on the neck of the crt,
the owner took it apart and carelessly broke it... worked fine before
(I wonder why he took it apart...).
I carefully soldered across all contacts with small wires, but now I
obtain only a whiter than white picture with a slightly reduced height
(brightness control totally uneffective)... Could I have accidentaly
damaged any component while soldering, or could it have been caused by
operating the tv with the broken pcb? Where should I start looking
first? Any help would be greatly appreciated!
regards
Arménio Pereira

 

[Asimov]

"Arm?nio Pereira" bravely wrote to "All" (25 Mar 04 04:59:26)
--- on the heady topic of "help needed with broken crt neck pcb"

The pcb damage could also have involved other components and there
might be a hidden crack in one of the crt bias resistors. Check all
the resistors involved with the G2 pin especially near the pcb crack.
An "open" resistor in G2 circuit could easily make the picture white.
Hopefully that's all the damage there is. Good luck!

AP> From: armeniopereira@hotmail.com (Arm?nio Pereira)

AP> Hey there! I got a small tv with a broken pcb on the neck of the crt,
AP> the owner took it apart and carelessly broke it... worked fine before
AP> (I wonder why he took it apart...).
AP> I carefully soldered across all contacts with small wires, but now I
AP> obtain only a whiter than white picture with a slightly reduced height
AP> (brightness control totally uneffective)... Could I have accidentaly
AP> damaged any component while soldering, or could it have been caused by
AP> operating the tv with the broken pcb? Where should I start looking
AP> first? Any help would be greatly appreciated!
AP> regards
AP> Arminio Pereira

 

[Ken Weitzel]

Jerry G. wrote:

If that is the only place that was disturbed, then the fault has to be where
the work was done. Most likely in the soldering job, some traces are most

Or, that was the reason the original owner took it
apart in the first place....

Ken