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#602
10-11-2022, 03:08 PM
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Ok I was not waiting the 15 mins that they recommended because of the thermistor so in running it the 145 was 146 the 190 was 183 the 275 was 269 very close but here’s the kicker I pull the 6bk4 cap off no difference at all and I shut it down then after about a minute turned it back on and the voltages started dropping fast then all of a sudden they instantly jumped up To a good level again. It’s like a momentary short then it was gone. When they drop b+ stays good.
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#603
10-11-2022, 03:35 PM
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Ok, So there is still a problem with power supply voltages going up & Down...
Possible short, possible tube using too much current. Problem, current meter does not measure above some unusable value.... Timmy you can make your current meter measure more current, but you gotta make an adapter for it.... First, in the uploaded pic. Fig. 1 Just FYI this is the only way to measure DC Current in any circuit. You have to cut the Current Path and insert the Current Meter into the path. Second, This is kinda experimental, Since you have 2 meters, you can select one meter you want to use as your current meter for this tv. It needs to be able to measure about 700ma max. Fig. 2 shows the start of my experiment, Take your current meter - set it to the current DC Scale you will be using, It needs to be the MAX Current, I believe it was pretty low. If there is more than one DC Current scale, be aware you will not be able to switch scales with this little mod... Measure the resistance of the Amp-Meter set to the Current Scale you want to use. Find this resistance, I believe it will be around 5 - 12 Ohms maybe less.... Find another resistor in your stash 1W or so, that is the same value. Put that resistor across your current meter leads as in my Fig. 3 pic. This will DOUBLE the range of your current meter in it's present scale, HOWEVER, your meter will ACTUALLY be reading ONE HALF of the current passing through it.... Remember Current in Parallel Resistors Divides according to resistance..... So For Example, if your meter reads 10 Ohms, putting a 10 Ohm resistor across the probes will give the measured current 2 Paths One through the meter, and the other through the added resistor..... Find the equation online to Add Multipliers to the meter's ability.... How? 5 Ohms in parallel with the current meter will 3X I Believe the meters range... Once you build this circuit you will have to test it with known test circuit so you know it's giving you somewhat accurate readings..... Then, you can monitor current paths in this TV that may be using too much Fossil Fuel generated electricity when you turn it off & back on and have all those low voltage problems.... Hurry though, this blasted thread is approaching 50 pages..... Good Luck.... .
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Yes you can call me "Squirrel boy" Last edited by Username1; 10-11-2022 at 03:40 PM.
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#604
10-11-2022, 03:59 PM
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The voltages when turned on drop instantly no time for a tube to conduct then it just spiked up voltages went right up almost to say a switch was switched from short to no short I still think this may be a ceramic disc to ground or otherwise.
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#605
10-11-2022, 04:15 PM
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Quote:
 this one, to be exact https://www.amazon.com/Etekcity-Digi.../dp/B09K7P86N7
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=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために Last edited by Yamamaya42; 10-11-2022 at 04:18 PM.
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#606
10-11-2022, 06:44 PM
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Att Timmy!
http://suzaku.live-evil.org/1011221837.jpg This Mostly OK working oscilloscope can be YOURS for the price of shipping + a probe that you can get on amazon! all you have to do is PM me if you are interested!  
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=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために
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#607
10-11-2022, 07:10 PM
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Quote:
 If I still had the spare scope I sold a few years ago I'd have made the same offer. Out here good Scopes can still be found at swapmeets and hamfest for $10 if you keep an eye out long enough.
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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
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#608
10-12-2022, 08:19 AM
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I don’t understand why if v6 is pulled out the horizontal oscillator won’t run but put it back it runs but still low hv so I guess this whole crazy problem is between the horizontal oscillator and v6. If there is something interfering with the oscillator then it looks like only 2 areas pin 13 from the flyback and pin 9 to the sync amp.
Last edited by timmy; 10-12-2022 at 09:07 AM.
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#609
10-12-2022, 11:15 AM
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Again, given the limited tools you have on hand, it's very unlikely that a complicated issue like this can be worked out.
It's like trying to play Jenga on a crooked table with your eyes closed. Vertical sweep is dependent on the boost from flyback transformer, so that has to be working, high voltage is dependent on horizontal oscillation being correct and at the right frequency, amplitude and waveform, and if it's NOT , the horizontal output tubes can go into oversaturation, overload the power supply and rob power from critical systems, like the horizontal oscillator. Or, something that controls the horizontal oscillator can be in play here, the signal shown on pin 9 of V12 is key to timing and control of the horizontal oscillator, generated by V10, I'm not sure what effect the removal of V6 has on V10, but the signal path goes that route. But as I and others have been saying, with just DVMs, you will be very unlikely be able to crack this nut.
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=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために
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#610
10-12-2022, 03:56 PM
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The 6bk4 has got a light blue color inside and pin 5 is 245v and pin 1 is 400v sams says both pins should be 360v and adjusting the hv pot don’t bring up the voltage on pin 5 maybe this is holding the hv down got a new damper in. And tried another 6bk4
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#611
10-13-2022, 09:39 AM
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A blue or green glow from a 6BK4/A/B/C is normal, it just means that you are getting a good dose of x-rays, and it would be advisable not to get angry at anything, unless you want to suddenly turn green, increase muscle mass by 300%, rip up everything you are wearing, and terrorizing everyone near you by grunting and growling at them in a primeval nature!
 As for not being able to adjust the HV, if it was low to start with, this could explain why adjusting R11 has little or no effect, a test you may try is to REMOVE the cap from the 6BK4 and measure the HV at the point there, this disables HV regulation, so be careful not to let it arc. If there is no significant rise in HV with the cap off, then the problem is not the regulator, but if it does go up, 22-24k or more, then it is the regulator, if you do see a rise in HV, limit how long you run it with the regulator disabled, as it will stress parts over time.
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=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために
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#612
10-13-2022, 10:24 AM
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Ok so I have the chassis out again and I tried taking the cap off in the set 20kv no higher I have the yoke plugged in on the bench waiting a few minutes to warm up both boost voltages are there tried 3 rectifier tubes just won’t go above 20kv cap off or not again subbed some tubes nothing make a bit of difference the other voltages that we’re dropping don’t anymore since I wait for warm up. I even tried the 0039 and 0068 caps the old ones which are good still. The 140 at the hot is around 160v and the oscillator tube is still giving voltages that are to high 6 and 3 are 165v.
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#613
10-13-2022, 10:29 AM
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So if the frequency of the horizontal drive is off besides resistors, capacitors, tubes, horizontal coil, which tests at 85 ohms what else is there to look at maybe the flyback.
Last edited by timmy; 10-13-2022 at 10:43 AM.
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#614
10-13-2022, 11:40 AM
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The frequency and amplitude and shape of the signal has to be right. Example, if the sign-wave at pin 2 of V12 is wrong, then the signal at pin 5 of the horizontal output tubes will not be correct, also, if that signal is not aprox 150v p-p, HV & sweep could be low.
Also, if the signals in/out of V12 are nor right, there could be a problem with synchronization.
__________________
=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために
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Linear Mode
