Hey guys,
Happy new year to all!

Im still having an issue with my Maggie combo with the horiz fluttering upon warmup.

I think I might have found the issue, it's in the horiz effiency coil. Has anyone ever seen this before? The coil actually has 2 parts to it. One coil on top of another with about a half inch between them on the rod. I was also told that adjusting this coil will fix the horiz width. Well it doesn't. The width is stretched and if I apply heat to the coil, it seems to make the screen flutter. This coil is really close to the Horiz osc tube also. Can this coil change resistance with heat?

Thanks!
Shawn

I don't have the service lit for that set here, but generally speaking, a horizontal efficiency coil is not used to adjust width. It is, on most sets, a fairly critical adjustment used to tune the horizontal output circuit to resonance.

If we are indeed talking about the same thing, the main things affected are the horizontal output tube and the flyback, both of which are likely to get destroyed quickly if this is set wrong. Generally speaking, they tune like transmitters. If you are very far off resonance, the tube and plate tank (in this case the horiz. output and the flyback) will draw way too much current.

If you have changed that coil setting, I would read up on the procedure before you turn it on again. It should be in the Sams. Generally speaking, this will involve checking the horizontal output current while tuning that coil, and checking the 6bk4 current while setting the "HV adjust". The procedure most likely has to be done more than once, until everything looks ok at the same time.

I have no idea why the screen flutters when you heat the coil. I would be suspicious some other component or maybe a solder joint in the immediate vicinity.

John

being i have fooled with many magnavoxs, i can give you some advise . Check all solder joints, they seem to be a issue with older magnavoxs .

If I have a possible leaky phase detector diode, (im assuming this is the diode set that is encased in a black plastic looking box with the 3 terminals coming out the bottom) could this drift when it warms up...

Does anyone know of the values of the horiz phase detector diodes? And where can I get a new one?
Thanks..

You can use two 2n4004 diodes and make one. Just note where the cathodes are on the old device and solder the two diodes in place of it. It's worked well for me in the past.

On a rare occasion you may need to touch up the phase detector slug, but its rare...

There are NTE/ECG subs for those.

I went to Fry's last night, I picked up a bunch of Zener Diodes NTE, what should I use, I already tried some 2.7 volt 1 watt, and I have absolutly no stabilization I can stabilize it but a touch on the dial either way it comes out of lock, and the longer the set is on, it drifts, I picked up some 8.3v 1 watt and some 27v 5 watt diodes too, would these work? Mabye the problem wasnt the diodes at all... I bought some freeze spray, and had no effect on any of the conponents on the horiz osc board..

You don't want to use zeners for this. Use a pair of small, low power diodes. Just about anything should work as they won't see much voltage, or current (do you have any junk electronics around). High power diodes might be too slow, or have too much capacitance for this application and zeners certainly won't work.

How do the original diodes test? The few times I've seen this problem, one or both of the diodes failed a simple resistance test with a VOM.

They seem to have failed the test on one side.. Thanks for that info, when it comes to diodes im stupid.. Ill pick some up tonight !

Yes, stay away from zeners as Andy stated. They are meant to regulate voltage and do not do well as HO phase diodes ;)

Once you get the diodes in, the erratic ho drifting problem should go away. I had the same problem with a few sets that used the dual diode-pack phase detector

Well I replaced the diodes. I have horiz lock again, but still doing the same thing.. After 10 minutes of operation, sometimes sooner than that, the screen seems to start squiggling back and forth, then eventually looses lock, then I have to adjust for it. Then looses it again as it goes back to where the dial was origianally. This is wierd!!

BTW, the interesting thing is that images that have rapid movement and colorful seem to affect the horiz squiggling and loss of sync faster and more erratically than images that are not moving, (like a dvd that is paused) then it just squiggles and doesn't seem to lose sync, but just squiggles back and forth. Oh when I say looses sync, it just looses enough to tear the pic, but it's not like way off or anything, just barely enough to tear the picture.

If this set uses circuit boards, you may have a solder joint failing or a trace that is breaking loose. I would focus your attention to the horizontal AFC and oscillator sections. Re-solder the tube sockets to be on the safe side.

Using a very well insulated stick (piece of wood or PVC) press on the board a bit. Note if the condition worsens or gets better.

If that does not help, check voltages on the horizontal afc tube to see if they are fluctuating when the symptom occurs. YOu may have a film cap that is trying to turn into a resistor.

The Magnavox part number for the afxc diodes is 50093-1 This crosses to an NTE 178MP . That is a matched pair of 50v silicone diodes.

Bill R

Well tonight I went over my solder traces and replaced some resistors corresponding to pins 1, 2 and 3 off the oscillator tube, no change. does anyone know a quick easy way to test the mica film caps? My inductance tester sucks... And I was told that a 820pf film cap may be bad, I cannot locate it, this cap is supposed to couple the AFC

Hey guys, on the Oscillator board, there is this black cap, standing vertically. It is black and it's an axial type, on it it has yellow writing, it's a Sprague, .01mfd at 400v. I pulled it from the board to test it, It tests ok on my crappy ESR meter, bit I can only supply 9v to it.Anyway I reinstalled the cap, and now the set pops the breaker when I power the set up. Not right away but before the raster shows up. Now I might have put the cap in backwards. The cap has a yellow ring around the bottom. Is this cap uniderectional, or multidirectional? I feel really dumb... It was late and I probably should have just gone to bed instead.

At that rating, its probably not polarized.

Pull the horizontal output and oscillator tube and see if the breaker still pops.

Are the orange drops polarized?

Older orange drops often had a marking to show which side should best be put to ground, but it really isn't a big deal. (old paper caps were the same way) You can install them either way. I'd replace that black cap as they aren't the most reliable. Double check your work in that area; something else might be shorting the circuit. I once put one end of a cap through the wrong hole in the PC board and it took me years and years to diagnose.

Ok good news!
Got te set back up and running again, was a bad solder connection from the .01mfd 600v sprague orange drop coming off pin 2 of the ocs tube. And suprisingly, the set has now been on for 20 minutes, (still on and counting) and it hasn't seemed to screw up yet! Think it might have been a bad solder joint I missed! Keepin my fingers crossed...

Well I ran this set for 6 hours yerterday, it started it's fluttering thing again... So i left it on! I figured screw it, im getting sick of this, let the part completely fail and then ill find it...... Well..... it did... Now the horiz is so off it shrunk the sides of the screen, If I turn the knob all the way to the left, I can see the raster, but it's far off.. Its like the phase is shifting over on the dial, the horiz lock was in the middle, now it's far off the dial, I can get it back by turning the effiency coiil, but I dont wanna do that, ill make the flyback turn into a pop tart. It used to get better if the set cooled down, not now, it's way off. Im going to replace all the film, orange drops and mica caps in the AFC circuit.. Lets see if I cant fix it..

Sounds like the horizontal frequency is changing. The problem must be in the horizontal oscillator. If it's temperature sensitive, try applying hot air when it's cold, or freeze spray when it's hot and acting up. It's probably a cap, or resistor that's changing value with temperature. This would explain why you can't find anything when testing components while the set is off.

It doesnt seem to be temerature sensitive.. I tried freeze spray and heat, neither seem to change anything. But ill keep plunking away,

Does anyone have a schematic on this chassis I could purchase a copy from them? U9109BB build date 8/1966

Thanks

Got it working!!! No more glitching! Ill tell you what I did as soon as I can figure out what I did......... Im going to swap this chassis into the remote unit I picked up...

Got it working!!! No more glitching! Ill tell you what I did as soon as I can figure out what I did.........

Ha ha ha ha! The mystery fix! Had a few of those myself.

I went looking for the Sams. The closest I came up with is chassis U908-01-00. A ton of models come back to that same Sams folder. If you need it let me know.

Set 887 floder 2. I think his is a U911/919/920 series. I don't think the 908 uses the same crt. That's what I came up with from the original thread.

Bill R.

Cool thanks guys, looks like it's working great now, the only issue in that the horiz width is stretched a little and the horiz pincushion is out. Does anyone know wwhat controls this?

FYI the horiz pincushion was out due to the yoke. Hey this tv is sitting with no chassis now.. Does anyone have something I can put in there, I dont care if it's a magnavox, RCA, etc.. Or if it's tube or solid state, just want the set running again. I can retrofit it to work as long as the chassis will operate with the 23EGP22/25GP22/25AP22 CRT.

Well im parting this set out, has a good 23EGP22 crt and stereo unit and cabinet. Anyone interested??

Well im parting this set out, has a good 23EGP22 crt and stereo unit and cabinet. Anyone interested??

I may be interested in the record changer if you wish to get rid of it. I have an older model Magnavox stereo that needs a changer.

Is the FBT still good? I'm having some issues with a '68 Maggie combo, would it work in a '68?
Mark

Do you think the stereo would work in my '65 Maggie combo w/remote, or possibly use it for parts to fix my dead stereo?
Mark

Hi mark, the fbt is cooked in this unit, the stereo is good. , I dont think the stereo will interchange , due to different components in the reciever, I have both styles the remote model and the non. I can say that the recievers look close, but the add ons for the remote unit are different. The stereo parts although do look interchangeable. If you want, you can have the stereo. Just pm me your address and I can send it to you, just cover shipping. Do you have paypal?

Do you think the stereo would work in my '65 Maggie combo w/remote, or possibly use it for parts to fix my dead stereo?
Mark

Well guys, this set is nearly parted completely, does anyone need a great condition 23EGP22 CRT? And the cabinet I really hate to destroy.... Any takers?

That 23EG is a rare tube... Awful rotten tube, but rare. I can't figure an economical way to save it from down here, but I hope that someone up your way can save it.

(PS: Remote on its way as of last Friday)

Charles