Motorola ts907 low hv - Page 60 - Videokarma.org TV - Video

timmy · #**886** 10-31-2022, 11:56 AM

It appears correct at the flyback 9 is horz centering that’s right and pin 6 is next to pin 5 and it’s right to the focus coil. If the ohms are correct the coil could still be bad ? The voltages 640 and 770 are at the right locations.

timmy · #**887** 10-31-2022, 12:05 PM

Pin 8 v6 should be 230v normally but as it stands it’s only 160v if something is not conducting in that tube maybe this is the voltage buildup I have the new 2.2pf cap just a thought even though I disconnected it before it won’t make a difference if the cap is bad. At this point I don’t know if I should put the old k1 in even though the resistance’s are not right unless I screwed up the one I made I don’t think so but never know all this is tied together video focus voltages.

Yamamaya42 · #**888** 10-31-2022, 12:51 PM

The heating of L42 is unrelated to K1 or the state of V6, working or not, this was verified when you took C59/C60 out of the loop and it had no change on the heating of the coil.

So it has to be local to the FBT, focus coil and L42, but not the 1V2.

timmy · #**889** 10-31-2022, 01:07 PM

Quote:

Originally Posted by Yamamaya42

The heating of L42 is unrelated to K1 or the state of V6, working or not, this was verified when you took C59/C60 out of the loop and it had no change on the heating of the coil.

So it has to be local to the FBT, focus coil and L42, but not the 1V2.

I don’t know where a problem could be at the flyback I checked all the connections I didn’t want to miss anything at the flyback. Would a damper have anything to do with what’s going on here. So I wouldn’t think the 130pf would be bad.

Yamamaya42 · #**890** 10-31-2022, 02:02 PM

Not sure what is going on here, I do not think it's the damper, could be C96, but not sure what unhooking it may do, the way they have this set up is strange.

timmy · #**891** 10-31-2022, 02:09 PM

Quote:

Originally Posted by Yamamaya42

Not sure what is going on here, I do not think it's the damper, could be C96, but not sure what unhooking it may do, the way they have this set up is strange.

That’s Motorola for you they had to be different

timmy · #**892** 10-31-2022, 02:14 PM

Guess I’m at a standstill.

timmy · #**893** 10-31-2022, 03:14 PM

Well I haven’t had a decent picture to set up the focus but I found that when the slug is out to much L42 seems to gets hot faster but when it’s in further it takes longer to heat up again I’m sure it’s supposed to get warm under normal conditions so until I get a good picture to focus I’ll leave the slug in more for now. So now I have to figure out what to use to keep the coil in it’s holder hot glue may not be good enough.

Yamamaya42 · #**894** 10-31-2022, 08:11 PM

Epoxy?

timmy · #**895** 11-01-2022, 05:35 AM

Quote:

Originally Posted by Yamamaya42

Epoxy?

Well I want to make sure it can dissipate heat rather then trap it in. If the temperature don’t exceed the melting point of hot glue then it’s good.

Yamamaya42 · #**896** 11-01-2022, 07:32 AM

Hot melt is a bad choice for holding such a coil, as it will get soft as it warms.
Better choice would be MG Chemicals - 8329TFF-25ML 8329TFF , thermal epoxy. $21
or silicone type 2.

timmy · #**897** 11-01-2022, 11:15 AM

Ok here’s what’s happening now the 770v tap is off the 640v tap but to make 640v it goes through a 47k but L42 is tied to the 640v tap befor the 47k at pin 1 on the flyback so there is almost 780v on both sides of L42 so I changed the focus coil it did nothing infact I had the antenna on and again it flickered clear and almost instantly L42 and focus coil got super hot. I don’t know what’s going on here I thought I had it with the position of the focus coil but something seems to be getting in the 640v tap I don’t know.

Yamamaya42 · #**898** 11-01-2022, 11:45 AM

The boost tap is pin 7 (should be) , L42 is pin 1, which is on the bottom of that winding, so there should not be boosted voltage at L42, but only the base bias that's fed to pin one.

What you may want to do is double check the resistance of that winding.

.8 .5 .45 & 9 ohms for each taps .

timmy · #**899** 11-01-2022, 12:28 PM

Quote:

Originally Posted by Yamamaya42

The boost tap is pin 7 (should be) , L42 is pin 1, which is on the bottom of that winding, so there should not be boosted voltage at L42, but only the base bias that's fed to pin one.

What you may want to do is double check the resistance of that winding.

.8 .5 .45 & 9 ohms for each taps .

Yes pin 7 is for the most part pin 1 they are so close they should be the same there’s nothing between 1-7 that shows.

Yamamaya42 · #**900** 11-01-2022, 12:44 PM

Quote:

Originally Posted by timmy

Yes pin 7 is for the most part pin 1 they are so close they should be the same there’s nothing between 1-7 that shows.

Incorrect.

It just looks that way due to artifact errors from the poor scan of the schematic, pin 7 skips over 1 & 2 and connects to the 3rd tap of the winding only, just under where pin 5 is.

it should be .5 ohms from 1-7.
or so it says on SAMS.