Once the TV warms up, and the 275, 190, and 140 volt supplies drop down, how far does each one drop?

Is the 385 volt supply constant or does it also drop a bit?

What is the current being drawn from each supply?

jr

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.

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....

http://videokarma.org/attachment.php...1&d=1665520444


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....


.

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.

he now has a meter that can measure 10a :o

this one, to be exact https://www.amazon.com/Etekcity-Digi.../dp/B09K7P86N7

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! :yes: :D

:thmbsp::thmbsp::thmbsp::thmbsp::thmbsp:

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.

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.

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.

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

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.

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.

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.

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.

So how is synchronization done when everything around this area is ok.

Phase-locked loop controlled oscillator.

Keyed off the sync pulses of the incoming video signal, shaped and processed by the SYNC SEP & SYNC AMP and passed on to the VERT MULT & HORZ AFC respectively.

However both of these have the ability to free run w/o need of control input in a randomized mode.
But in your case, horizontal section is having a problem doing this, there could be any number of things causing it, a resistor or capacitor that does not sit well with the circuit, even if they test OK, the wrong types can upset things, as been mentioned , it's a tuned circuit using feedback including the yoke, and the FBT, it's very easy to make it unhappy. Especially with dual horizontal output tubes...

I had mistakenly reversed 13 and 14 on the flyback and that’s where the bars came from I since made it right and the bars are gone so I don’t know if this has something to do with this hv problem

I’m going back at what I did I originally took the old flyback out and put the new one in and all was fine only no video then I thought maybe the fly was defective and put back the old one that is when I reversed 13-14 then put the new one back in again with the mistake on those 2 wires and had the bars but since fixed that and this is what I’m left with low hv.

That would have introduced a major feedback phase loop error.
I'm not sure now what it could have done in there like that with it out of phase. :(

All it is a 1 ohm coil I checked it and it’s good but really how much oh a feed back voltage could it have made to damage let alone to affect the horizontal drive.

Look at pin 6 on the convergence connector, to which it is also connected to, that is 300v ptp there, who knows what it could have done with that signal inverted.

What would be suggested is that you go over the entire horizontal circuit with a fine tooth comb and re-check every resistor and cap, and if they do not check within 10% replace.

Also, this can check caps for leakage to some degree, https://www.amazon.com/ALMOCN-Transi...s%2C138&sr=8-6

but, out of circuit only :(

Those 2 connections are separate what I did was reverse the connections 13 didn’t go to ground

You said “you had mistakenly reversed 13 and 14 on the flyback”

This tells me that the windnding was putting out a signal 180 degrees out of phase from what it should have been.

The wire that should have been on #13 was on 14 and vice versa, this is what you are saying, right?

Then you should re-check the whole area.

I did check all connections on the flyback the 13-14 on the coil is top and bottom it was reversed within the coil 13 was not on ground it’s just how the wires are oriented the same as reversing a coil polarity to push or pull like a solinoid but it was reversed. I followed that 13 to 2 33k resistors are 35k and a 150k that’s 163k.

again, that means it was out of phase, and you should check things.

Well then 150k at 163.7k is just about at max then.

I changed a few resistors still no change but the hot are to have 140v but I’m getting 190v would this still be the case of the drive being off.

All I can add is, perhaps you can try to do direct video input again at test point B, and hope to get it to lock on, perhaps the horizontal frequency is way off.

I really do not understand the way things happened here when last week the bar issue was first mentioned.

Snip/paste.
“I’m going back at what I did I originally took the old flyback out and put the new one in and all was fine only no video then I thought maybe the fly was defective and put back the old one that is when I reversed 13-14 then put the new one back in again with the mistake on those 2 wires and had the bars but since fixed that and this is what I’m left with low hv.”

“I had mistakenly reversed 13 and 14 on the flyback and that’s where the bars came from I since made it right and the bars are gone so I don’t know if this has something to do with this hv problem”

Why was it not mentioned back then that the FBT was swapped from the new back to the old when the bar issue started?
This just lead to mass confusion and had people looking to the wrong places for the reason for the possible cause.

It's really somewhat a mystery to me why it was swapped after it was shown to be OK with the direct video input done previously, the issue of not being able to get a signal in via the tuner is not related to the FBT, more so the front end, (tuner/IF).

Again, I'm not sure what having that winding hooked up reversed did, but it could not have been very good for the set.

Please be more straightforward about such things to avoid future confusion, had you said that the bars started after you put the old FBT back in, things would have been much more clear.

Remember how I was immediately suspect of the reduced screen width? Something was telling me there was something wrong there.

Ok so I put the old flyback back in and the voltage at the hot is now 130v other voltages are looking better on v12 v10 and maybe once the anode is on the tube it will show higher hv now with the reg cap off and warmed up I’m getting 24 kv so once the chassis is put back in hopefully the voltages level out I can’t expect to get perfect voltages with the Chassis on the bench. I would have expected the hv to rise to at least 30kv with the reg cap off.then again the crt acts like a capacitor so it will probably rise to 30kv.

So back on track hv very good after 15 minute warm up voltages are still not right
275=266 190=187 145=143 not bad but after it running additional 10 minutes the voltage drops off
275=255 190=170 145=130 and no matter where the voltages are still no video. Using the new dvm if I’m reading it right on 10 amp or the other amp settings it’s showing either 0.055 or 055 so I’m not sure if this means 550ma.

I did notice I get activity from all vertical controls except the vertical centering it does absolutely nothing no movement of the screen so I’m not having video maybe I Should look into vertical maybe the horizontal and vertical cannot sync because of a vertical problem. What could cause the vertical centering to quit while everything else works.

That would indicate 55 mA...where are you reading current?

jr

Output of the diode
The last time I used my 500ma meter in the same place and it went to the end of the scale

Was the new meter set to “10” and the probes plugged into “com” and “10Amax” positions?

jr

yes it was

Should read “0.55” on the “10” scale if the current is 550 ma, recheck your readings please. Perhaps double check with the other meter, see if it still pegs.

jr

Yes I think when it was on 10a it was 0.55 I mentioned in a previous post I didn’t put the decimal

I have to again ask myself if I messed up with the power supply caps since there is 3 different voltages and I checked and double checked if I had maybe one of the 190 and 275 backwards that would explain everything like the 145v to the tuner that comes from a higher voltage with a resistor to drop it to 145v it don’t make sense to have 2 feeds for 190 and 2 for 275 I would think the 275 would have had 3 feeds and 190 have 1 because there is 24 arrow connections while the 190 only has 9 arrow connections but I’m going to go back and check these arrow connections again.

Can someone that has the Motorola ts907 schematic tell me what the letter z means it has a 275 arrow where would this be marked where it goes.

Z and W are connected to the CRT heater...the connection of the heater winding of the transformer to the 275 volt supply is to elevate the CRT heaters to a voltage near that of the CRT cathodes, to reduce the likelihood of s heater/cathode short.

jr