Perhaps you could post a under chassis photo? Might be able to spot something amiss. :scratch2:

jr

Ok here it is. Sorry upside down again, I pad crap

This is going to take a while... having a hard time making out much detail under V-11 and V-9 ... also not sure if I see R-60. :scratch2:

jr

Yes r60 and 62 are 10 meg and they are in place. I guess I should think about a possible defective cap like the .1 at the vert hold pot which runs to the vert oscillator. I already had a cap that tested good but was bad in the circuit so that's the next thing I'll be doing.

Looks like the .1 should be at the vert size pot, not the vertical hold.

How are you testing the caps?

jr

The .1 is actually at both but separated by the 2.2 or 3.3 the resistor off the vert hold pot.

duplicate... ignore

Take another look at the schematic... I see no connection between C-63 (.1) and the 3.3 meg resistor (R-57) that goes to the vertical hold pot.

How are you testing the caps?

jr

The connection is there where the vert hold and size pots are connected via resistors it's under the tie strap it goes to the vert oscillator . I have a Dvom that checks caps but does not apply any voltage to simulate actual in circuit operation.

I don't see a connection on the schematic. I urge you to look at the schmatic and compare it and the wiring in the area of these two pots.

The cap may very well be leaky at operating voltage... Dvom measure of value only will not indicate that problem... if you have an old cap in that location, replace it, and any other old caps in the vertical sync, osc and output circuits.

jr

I am aware that my meter won't check it in operating time so I will be subbing a few caps to maybe weed out a possible bad one. So I checked and good point my mistake it was not separated by the resistors I checked the schematic and it's all in place. Thing is first time on I had vert then it was gone so it may be a cap I hope. And there are no old caps left all changed and also all the Micas in the verticle and horizontal.

Well still no luck here as I subbed all the key caps for verticle and no change i am wondering if the verticle centering could screw all of this verticle up the way it's doing although the vert centering does move up and down but don't know if this could be the cause. I would rather know if this may be it befor changing it I found have a spare.

Maybe your problem is further back. Have you gone over the sync circuit ?

Yes I went over the SAMs and it all looks good sync v11 and at the 6sl7 and between the both, caps and Micas. I have never had something like this after going over what seems like everything and not finding a problem I thought it would have been obvious. If the vert centering pot goes bad being there is hv running past it would the ohms go down in value rather then up, a kind of carbonizing ?

This may sound like cheating, but on my VT-71 when one axis of deflection was running off frequency I got out my cap decade box and played till I found I could add capacitance in parallel with a stock cap to get it into sync range. It worked and I've not looked back...It makes a decent last resort.

It makes no sense there is a problem like when I parallel the .004 cap with a .01 it seemed to work but not perfect but now with the right hv caps that trick don't work anymore but I did parallel caps and I just cannot get it.

Ok resistance checks on 6sl7 and 12sn7 sync tube are actually perfect according to SAMs.

Very much a long shot, but have you tried another CRT that is known to be good? :scratch2:

jr

yes I tried another crt same thing. But I did a resistance check on the horiz v13 and all pins are perfect except for pin 2 unless SAMs is wrong but it shows that what should be there is 20k-520 ohm but I'm getting 2.223k so this is not right . There is the horiz afc and block oscillator trans that pin 2 leads to one of those trans and I checked the resistors on both transformers one in the can and the one at the other trans and both are good .

See post 31 and 32 in this thread... does the measured resistance at pin 2 of V-13 change when you vary rhe horizontal sice control?

jr

There is no change in resistance on pin 2 of v13 when the horizontal size pot is turned . but the voltage tests do vary with the movement of the size and hold pots.

Are you measuring the resistance from pin 4 of M-5, like the note at the bottom of the table says?

jr

Sure did

C-75 could be shorted, but I doubt that the horizontal would work ok if it was... a real head-scratcher. :scratch2:

jr

That's a 900mmf that cap along with the other Micas were changed but each one I replaced I tried the set and after all of them were replaced I was left with the same problem. I checked the horiz afc and block trans and ohms are perfect. So I don't know what it is with pin 2 or if it even has to do with this odd problem.

Could the blocking trans have a primary to secondary or windings to frame short?

These transformers are small round things dipped in wax and the one trans is on a tie strap and the other is in a can on top and I took that apart and that one has insulating paper wrapped around it. So I guess it's safe to say I don't think there is a winding short to ground unless the ground was leaking in from somewhere else , I don't even know where to start to look for a possible ground leak into the verticle, and There is no 60hz hum in the audio.

Still didn't figure this out, but there is 2 10meg resistors at the 6sl7 that I checked and also tried others and didn't work was the same no different but the one 10meg that is across pin 4 and 6 if I put a 1 meg across the 10meg I get a picture and vert hold the linearity is off on top and the hold is Alittle touchy. pin 6 is wired for ground and the one end of the .004 is also tacked to ground. It seems as if the tube is not conducting by why with a 1 meg it calls for 10 meg. If I try a 1 meg across the other 10meg it works very little bad picture and no response from vert hold or size. All this changes with the one resistor at 4 and 6 . I can't measure the voltage on the plates of the 6sl7 with a Dvom I won't get an accurate reading but measuring I do get a reading of 120 Vdc and 75 Vdc the SAMs shows a lot more so my meter won't tell but changing that resistor to a 1 meg I'm thinking lowering that resistor seems to allow the tube to conduct with possibly low voltage on the plates but the screen is super bright. The plates get voltage from the hv with the resistors which check ok. This is nuts already, I'm open to anything at this point

Have you tried a different 6SL7? Possibly this one has grid emission. :scratch2:

Could there be a carbon path in the tube socket between pins 5 and 4 that is pulling the grid more positive than it should be?

You really need to get better voltage measurements... can you get another HV probe or fix the one you have?

jr

I tried several 6sl7 no change as for my hv probe tossed it last year could not fix it. Carbon path , well anything is possible but I need to find out how to know if there is a carbon path taking place befor I get into changing that socket. Do you have an idea how to determine if there is a carbon path. I don't here anything arcing nor do I smell any corona from hv. Pin 5 SAMs shows 320 Vdc and I find odd that the 6.8 meg at pin 5 gets warm but the other 6.8 don't.

I would unsolder all of the connections to either pin 4 or pin 5 and mesure resistance between the two pins... leakage as high as 10 meg or so could mess up the bias on the tube.
You really need to get another HV probe, as low HV could be te main source of the problem.

jr

I thought maybe low hv but the crt is super bright and I tried adjusting the ring on the 1b3 and of course no change. Should the tube remain in the socket when I remove from one pin and test?

The tube shouldn't make any difference, unless it is the cause of leakage... try it both ways. You could also check the tube itself for any leakage between pins, but since you have tried several different tubes without changing the symptoms, it is unlikely that you will find any leakage unless they all have the same fault.

jr

Timmy,
Did you ever try spraying any cleaner into the vertical hold and size control to see if it would stabilize the vertical roll? Did you try wiggling V9, V11, or V12 while the set is on to see if it helped? I come across worn and dirty contacts all the time in old equipment. The cause of all sorts of issues. Just because parts are swapped or tested doesn't always eliminate the root cause.
Do you understand how the vertical feedback loop works with this set? If you have a scope, check to see if you are getting the proper trigger signal to your vertical oscillator grid from the sync separator/ integrator network.
Ed

I did spray the verticle pots in the beginning thinking it would help but it didn't and yes I moved v9 ,11 , and 12 , nothing helped and I don't have a scope I'm an auto tech, lol so I wouldn't have that for a tv but I have 4 other of these sets I have done and never came across something like this I mean these sets are kind of simple but this problem is kicking my ass. I replaced every mica in the vert and horiz along with all the wax caps were done. After the wax caps fired up and the vert went down hill fast and since then I did the Micas one at a time to hoping to find the one culprit but after replacing all I'm still left with this problem. I checked to see if any carbon shorts in the 6sl7 socket and none showed up. And all the 6 kv caps new also. Just don't get what's going on I am out of areas to check. In the beginning it seemed like a resistor went up fast but I only found one 2.2 meg that went up to 22 meg so I changed it and the 2- 6.8 meg resistors at the 6sl7 measure around 7.5 meg not all that high since I think my other sets were around there to but they work . And thinking one was breaking down in circuit I subbed them and still make no difference. I also subbed the vert size and hold pots no change. And also moved v10 the oscillator no change.

Tim,
Since you don't have a scope you could try to isolate the trouble better. Disconnect/ unsolder C61 250mmf from pin 4 of V9. Leave C61 disconnected and then turn on the set. The picture should roll but, see if you can adjust the vertical size, if so set it. Next see if the vertical hold control has any effect on the vertical roll. If you can get the vertical roll to almost stop with the vertical hold in mid-position thats good. If the vertical hold has no effect or won't slow down enough then the trouble could well be a bad cap or resistor. The bad cap or resistor would determine the time constant the free running vertical oscillator frequency.
If the vertical roll can be slowed down and controlled, then I would next start checking the output of the sync separator. Try connecting a voltmeter set on AC volts, high range to start, to the end of the disconnected C61. You should be getting an AC voltage reading of some sort. You may have to adjust your voltmeters range downward to get a better reading. If there is no AC voltage present then the trouble is syn related. The integrated sync pulse voltage is what your trying to measure. Try these steps and let us know the results.

Ok I took the leg of c61 250mmf off and the size has very little affect and the vert hold also it's hard to see anything it's rolling so fast the hold I can see it slows Alittle from one end to the other on turning the pot the same for the size pot. I checked the cap pin for ac volts and I get .300 vac jumping around a bit. If there is a bad cap I may put in or a resistor I may have missed do you have an idea which one It might be. Maybe I put in a cap that is detective .

If you can't get the vertical to stop rolling with the hold control, (with the sync pulse disconnected) it seems as thought he vertical oscillator is off frequency. You should be able to get the picture to get close however, it needs sync to lock in.

You might check the capacitors in the oscillator circuit to be sure the correct value is there. Also, resistors for one that may have gone high in value or maybe one that was replaced with a value that is 10 off (Like 270KΩ instead of 27KΩ or .01 ᶙFD instead of .001 ᶙFd).

Just a thought. I realize how maddening it is!

This is what happens when I put a 1 meg across the .004 cap and if I measure across the resistor there is around 3 volts dc I'm also showing 2.7 volts ac as well.tried another .004. With out the resistor can't see a pic and nothing works. Almost seems maybe ground leakage or ac getting to ground and the resistor kills it enough to work Alittle, ah I don't know.

Timmy,
I compared the Sams schematic to the Riders for the TS-18 chassis. There seem to be a few differences and maybe errors. I' ll use Sams part numbers. Resistor R-59 should be 22 meg not 2.2 meg. Resistor R-56 is shown as 150K ohms not 100k. Also make sure C-61 through C-68 are the correct replacements,
voltage and tolerance wise. If trying these changes don't slow down the vertical then you can try increasing the capacitance of C-64.
Ed