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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Gary Smith
 
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Default CTC 197 Dead

Degauss relay clicks 3 times when power is turned on. No stand-by
voltages. Raw B+ at 170 volts. Removed H.O.T , stand- by voltages come
back., but regulated B+ at Cr106 160 volts. Raw B+ still 170 volts.
Disconnected reg. B+ at pin 3 of flyback transformer ,no difference.
Could it be IC14101, oscillator for Q101? Voltages on IC seem to be normal.
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Skype_man
 
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Default CTC 197 Dead

Is the HOT shorted? How big is it? Some 32/36" RCA
with "three strikes, your'e out", could be flyback. Ctc197
flyback is 237506. Look here. Sky.

http://www.freelists.org/archives/te.../msg01741.html



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Gary Smith
 
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Default CTC 197 Dead

HOT tested same as new with diode test. 36" RCa.

Skype_man wrote:

Is the HOT shorted? How big is it? Some 32/36" RCA
with "three strikes, your'e out", could be flyback. Ctc197
flyback is 237506. Look here. Sky.

http://www.freelists.org/archives/te.../msg01741.html





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John-Del
 
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Default CTC 197 Dead

Scope the collector of the HOT when you attempt a start. A badly
distorted waveform will indicate a shorted flyback

John

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RonKZ650
 
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Default CTC 197 Dead

CTC197 notorious for bad flyback. I put a meter on the collector of the
horiz output. Read AC voltage at turn on, then put a HV probe on the
anode wire and read the HV at turn on. A good working set has about
300vac rms on the output, 30kv on the anode. Of course you need a good
meter with min/max setting to really do this. The flyback if bad will
load down AC on the collector, but the basic readings will still be
usable. For example if you read 150vac at turn on, but only 2kv on your
anode, you know the flyback is bad or the yoke is bad or the CRT has no
vacuum or you have a shorted diode ect, off the flyback. Check the
diodes, unplug the yoke and the CRT board and see if HV increases. If
not, bad flyback. CTC197 not one of the better sets RCA has made.
Flyback probably on factory back order, always is.

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