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#16
03-14-2011, 01:19 AM
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I brought the 15 incher in tonight and pulled the back off, lots of black dust but not bad overall, wetness was apparently minimal, more like light splattering than a soaking.
Running it off the Isolation transformer to drop the voltage and keep it running I get 139 volts across the main filter cap. Measuring from filter negative to the Regulator I get .5v 12v and 0.0 volts, left to right looking at it face on. Measured from chassis ground (a shield) I get -12v, 0.0v -12v Nothing seems to be getting hot. If I plug it into the wall and let it go into shutdown I get roughly half the voltage on the Regulator but I get about 166 volts on the Filter cap. I'm not sure I'm measuring where I should, should I pull the Regulator and do a Diode check on it? The first two legs read pretty much shorted in circuit but that might be normal of course. 
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#17
03-14-2011, 01:24 AM
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Pictures
Here's a couple chassis shots.
BTW Charles, you are welcome to this set if you want it, you were supposed to get the Remote unit a long time ago!  I really just hated to see it going to waste in the open air back lot of a thrift store. I'd like to see if I can trouble shoot it first for the fun of it, but if it gets complicated I'll be glad to turn it over to you. The CRT looks very strong, it's not blue in person, the camera balance is a little off. This is a solidly built little set and it has some heft to it, not yet the era of BPC. P.S. I just put some batteries in the remote and it works! Last edited by Eric H; 03-14-2011 at 01:33 AM.
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#18
03-14-2011, 01:40 PM
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Just curious but what is the "ball bearing" control panel?
__________________
No wonder this circuit failed,it says "made in Japan"!
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#20
03-14-2011, 09:05 PM
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Quote:
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#21
03-15-2011, 12:09 AM
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Hi Andy, I'm not sure where I Should be measuring?
I measured across the Filter cap and it was about 166 volts with the set plugged directly into the wall, it was on but in shutdown at the time. With it powered up and running through the Isolation transformer (probably at 10 volts less than line) I Measured from chassis ground to the pins of the regulator and got no more than 12 volts on any pin and 139 volts across the Filter Cap. I didn't see any hum bars on the screen but I didn't have a signal. just snow. Quote:
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#22
03-15-2011, 12:33 AM
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The best place to check will probably be where the regulated B+ enters the flyback transformer. It will be the primary winding of the flyback with one end connected to the HOT collector and the other end will be the B+ input. There may also be a tap on the primary winding to provide the 200 volts to the video output stage. This is the way most solid state TV flyback transformers are connected.
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#24
03-15-2011, 02:39 AM
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OK, line voltage is 117 coming out of the Iso Transformer with the set running, normal line voltage here is about 125v.
The 135v test point has 127v, not far off considering the low input voltage. I pulled the regulator, not shorted, two legs check like a diode more or less, infinity one way, some resistance the other, the other two legs read pretty much infinity or at least in the megs. The Flyback has some test points and marked voltage points too, the 135 is running 127 there also, there is a TP for 200v, I read 125 there, a 24v TP has zero but I don't know if I'm measuring from the correct point (chassis ground). Also, hooked up a DVD player but couldn't get it to receive anything, tuner tunes up and down, picture flickers a bit when it jumps to UHF but no picture at all. Also, no sound, no white noise, not a peep from the speaker even at full volume. I'm starting to think maybe there's an open somewhere killing a voltage needed for these functions? There are two fuses, both OK. Soldering looks good underneath.
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#25
03-15-2011, 12:11 PM
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If the Variac is on 117, and the 135 line is at 127, you have a load on it. Those regulate VERY well when working right, and you can keep 135 with as low as 95 or so line voltage. I'd check the two 10uF caps (160 or 250v?) near the regulator, and also keep in mind that the HVR block might be loading down the whole set if it's leaky internally.
Charles
__________________
Collecting & restoring TVs in Los Angeles since age 10
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#26
03-15-2011, 03:57 PM
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Charles, Is the HVR the red thing in the 2nd anode line?
Any way to check it, it seems permanently attached to the Flyback. I'll sub those caps you suggest, I already pulled the Filter and subbed it with no effect. Update to my previous comments about no reception, I didn't have the r.f. Modulator plugged in, I found that out later last night when I was working on another set. I'll have to try this one again. Quote:
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#28
03-16-2011, 12:03 PM
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Quote:
Quote:
Charles
__________________
Collecting & restoring TVs in Los Angeles since age 10 Last edited by kx250rider; 03-16-2011 at 12:11 PM.
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#29
03-16-2011, 11:57 PM
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Thanks, I will check out these ideas and report back as soon as I can.
It's been pretty hectic around here though so I may have to wait a little while before I can get back to it.
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#30
03-17-2011, 12:12 AM
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I did decide to try getting a picture again, this time with the Modulator plugged in!
It works (with reduced line voltage) and has a great picture, the gray scale is off just a touch to the red side, I'm sure it'll adjust out easily. I also noticed it cuts off the right side of the screen, look at the Peacock tail in the first picture, I don't know if this is related to it's problem or not but I don't think a Sony of this vintage left the factory like that. Also there is no sound, none, nada, zip. BTW, if you want a nice 1960's NBC Peacock opening, the Mothers In Law DVD set has one!
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