Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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Default removing circuit board from RCA F27665 27" TV (chasis CTC203AX)

Hi,

I've got an RCA F27665 27" TV (chasis CTC203AX) with good sound and
menus, but no image. I believe this is caused by the glue on the
location L14401 coil, so I'd like to remove the coil, remove the glue,
then put the coil back in place. The problem is that the circuit board
doesn't seem to want to come off it's tray. I've opened up the set,
removed the circuitboard tray, and removed the hex nut along the edge
of the board, but the board still seems to be fastened to the tray.
Are there any other fasteners I'm missing? Also, is the problem glue
on the coil red in color?

Thanks for your input,

Mark

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Rono
 
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Be carefull not to force the board, but pull it away
from the tray firmly. They get stuck in there sometimes.
The coil IS the only problem. Solder it! Rono,




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Art
 
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Glue is usually slightly grey in colour, maybe a bit brownish. Like the
stuff from the glue guns. Best to physically remove the coil, clean the glue
residue form the pcb and leads of the coil, then reinstall the coil. Seen a
lot of guys try to just resolder them and have other problems later. Agree
with tender care in sliding the pcb out of the plastic tray, they do stick
at times and make it a bit of a chore.
"Rono" wrote in message
...
Be carefull not to force the board, but pull it away
from the tray firmly. They get stuck in there sometimes.
The coil IS the only problem. Solder it! Rono,






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Some of the boards are held in with the f connector nut, an additional
1/4 hex screw with plastic ferrule near the front of the board also.
Many time the heatsinks that go through the board are bent to stay on
the board, but they are bent so far that they will hold on the side
plastic rail. Take a flashlight and look under the board to see if
this is the case and CAREFULLY bend the tab back out of the way.

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Thanks for all the replies. I've already taken off the hex
screw/ferrule, so it's probably something sticking along the side rail.
I'll check that out.

Mark



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Art
 
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BTW, If indeed you see the on screen menue and volume control bar the
problem is beyond just that coil. the coil supplies the drive signal to the
base of the horizontal output transistor, allowing it to drive the LOPT and
develop the HV and other derived sweep and supply signals. You will need to
troubleshoot the video processing circuit including the jungle ic to find
the actual cause of the lack of video to the crt.
wrote in message
oups.com...
Hi,

I've got an RCA F27665 27" TV (chasis CTC203AX) with good sound and
menus, but no image. I believe this is caused by the glue on the
location L14401 coil, so I'd like to remove the coil, remove the glue,
then put the coil back in place. The problem is that the circuit board
doesn't seem to want to come off it's tray. I've opened up the set,
removed the circuitboard tray, and removed the hex nut along the edge
of the board, but the board still seems to be fastened to the tray.
Are there any other fasteners I'm missing? Also, is the problem glue
on the coil red in color?

Thanks for your input,

Mark



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5 May 2005, Art said:

BTW, If indeed you see the on screen menue and volume control bar the


problem is beyond just that coil. the coil supplies the drive signal

to the
base of the horizontal output transistor, allowing it to drive the

LOPT and
develop the HV and other derived sweep and supply signals. You will

need to
troubleshoot the video processing circuit including the jungle ic to

find
the actual cause of the lack of video to the crt.



Hi Art,

So, I removed the coil and cleaned off the small amount of glue that
was between the coil and the board and then resoldered the coil to the
board. Indeed, the problem persists, so what you say seems like it may
be true. Any suggestions as to where to start in the video processing
circuit?

Mark

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3 May 2005, dkuha... said

Some of the boards are held in with the f connector nut, an

additional
1/4 hex screw with plastic ferrule near the front of the board also.
Many time the heatsinks that go through the board are bent to stay on


the board, but they are bent so far that they will hold on the side
plastic rail. Take a flashlight and look under the board to see if
this is the case and CAREFULLY bend the tab back out of the way.


It turns out there wasn't anything catching on the sides, the board was
just tightly fit into the tray. I just needed to insert a flathead
screwdriver between the back edge of the board and the plastic tray and
give it a twist to free push the board forward.

Mark

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