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Dead Haviland
I fired up my Haviland this afternoon, and after about 90 minutes, the screen "flickered" and went black. Upon checking, found all heaters dark, so probably not a HV failure, but could be a power xfmr. Checked continuity across the cheater cord, and found none. Hoping for a bad solder joint, or a failed switch on the volume pot. Need to clean up some other repairs before I get to the CTC-4, and I can use my 100+ pound Kron-Hite supply to power it up if the xfmr is toast, at least to be sure nothing else fried when it shut down. Always something interesting when "playing" with vintage electronics. A couple of pics from happier days attached. The avitar is also from the Haviland. Kevin
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stromberg6 Last edited by stromberg6; 06-12-2016 at 04:18 PM. |
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there may be a fuse in the filament circuit.
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[IMG] |
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Nice to see a picture where the contrast isn't driven up all the way. Those sets were never designed to look like the HD's of today. Back off the contrast and the colors blossom.
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The O/P stated, there was no continuity across the power input. I don't think the power transformer primary would open, without making a burning smell. I don't remember a line fuse but it might have one of those surge limiting thermistors.
What is the chassis number of the set? |
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It is a CTC-4 judging by cabinet name.
One hack way of dealing with open primaries of power transformers that I like is to take a similar sized xfmr and jumper it's heater winding (assuming both use the same heater voltage) to the heater winding of the one in the set.....If only the line winding is bad then the set will come to life with the "helper" transformer connected.
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Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4 |
Audiokarma |
#6
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I vote for the switch on the volume control. Way too small in capacity. Changed countless numbers on color and B/W sets in the past.
I use a variac today to prevent killing the switches today. Just leave them on and ramp up the voltage. |
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Quote:
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Thanks for the replies. It's a 4A, late run with all the mods done at the factory.
Hoping to get to it as soon as I finish restoring my daughter's HH Scott 130 preamp. Not much between the line cord and the xfmr, just the switch and associated wiring. Needed to do a sound trap and ratio detector alignment anyway. Kevin
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stromberg6 |
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Audio is funky in mine too, like it has an intermittent connection somewhere.
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Evolution... |
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Is there a thermistor in the primary ckt--like on some sets? They like to crumble and fall apart..
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Audiokarma |
#11
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IIRC those may have used fuse links. Its nothing
more than a thin wire like #22 a certain length. Usually right at the interlock & sometimes covered with spaghetti. It was commonly done. 73 zeno |
#12
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Odd as it may seem, the two fuse links on a Ctc4 are in the heater circuit.
All that is in the primary is the power cord, interlock, 2- 56k resistors to ground from the 2 sides of the line, power switch and power transformer. Thats it. That's according to the schematic, of course sombody may have added a fuse or thermistor later. jr |
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I know it appears obvious, but have you checked the power switch? The switch is a bit small for the power requirement of a color set and I have replaced a few in my time.
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