Motorola ts907 low hv

[dtvmcdonald]

Originally Posted by Tim

It intends to show .002 distributed across the resistor. When making a replacement put a .001 to ground on each end of the resistor so the total is .002

Is there another resistor that is covered by the black splotch?

A more common interpretation of the separate component intent of that figure
is two resistors of half the listed value in series with the listed cap value attached between their center to ground. That of course assumes that the big black dot is meaningless.

You really need to get or borrow a scope to sort out messy problems like these.

[Yamamaya42]

Originally Posted by dtvmcdonald

A more common interpretation of the separate component intent of that figure
is two resistors of half the listed value in series with the listed cap value attached between their center to ground. That of course assumes that the big black dot is meaningless.

You really need to get or borrow a scope to sort out messy problems like these.

and a better DVM.

[timmy]

Well I have more problems I plug it in to check video again and now I lost vertical deflection so this has to do with no video and recently sound was lost I originally pulled the 6cg7 and the voltage draw stopped pulling down so I put the tube back to check injecting video only to find vertical is gone and now the tube in and no voltage draw. So it’s like whatever was shorting now burned altogether and no more draw down. This set is really bizarre.

[timmy]

So now chassis has to come out and this time it’s not going back in until I find a problem or problems.

[timmy]

So I’ll cut the 2 couplets out and test them if bad then I make them.

[timmy]

Originally Posted by Yamamaya42

remove V1,V2,V3 ,V7,V8.

feed video back to test point B like you did before and see how long it can run like that.

Well I never got the chance to pull those tubes , can’t run it with no vertical.

[Yamamaya42]

For something like losing vertical sweep, you will have to set the chassis up in the service position, if you have not done so already.

The makers of the set have anticipated the need for this, and normally left all wires long enough to prop the chassis up behind the set for easy access and still hook everything up, you just need to be sure the CRT is grounded.

Vertical deflection is dependent on 640v boost via 3 points, vertical height, vertical lin, and the output via C5, if this 640v boost has failed, or the parts it feeds have failed, vertical sweep will fail.
But to have boot voltage in the first place, horizontal sweep/ HV has to be working.

[timmy]

Yeah not sure how I’m going to do that being I don’t have the plug harnesses which would have been nice I’ll have to check into things first hopefully there’s something obvious. For no reason the vertical just dropped dead nothing I did except remove the 6cg7 tube for no more then 20 seconds. Well the wires may be long enough.

[timmy]

On k1 the schematic shows what looks like 24meg but on the schematic it looks like a dot next to the 24 so I checked early television museum schematic and it to looks like .24 meg is there a .24 meg resistor or is this a typo error.

[Yamamaya42]

Originally Posted by timmy

On k1 the schematic shows what looks like 24meg but on the schematic it looks like a dot next to the 24 so I checked early television museum schematic and it to looks like .24 meg is there a .24 meg resistor or is this a typo error.

clearly 24meg 2w, hooked to 275v, going down to .4v it has to be.
not a typo, scan error.

[Yamamaya42]

No telling what could have happened,
Gonna have to re-check the whole circuit, including tubes, power resistors, potentiometers, caps, etc..
I see no real reason for vert to fail w/o V10 being in there, but on the other hand, if you hot plugged it in/out, that may be different, no telling. :/

[timmy]

Well this tv has tell tale signs of it having been in humidity and dampness so I think it may have been a momentary loss in one of the vertical pots as I turned the vertical linearity pot and was alittle stuck at first and I still have boost voltage and all the vertical pots check out fine and vary with turning them. That 24 meg measures 30.59meg slightly high.

[Yamamaya42]

Originally Posted by timmy

Well this tv has tell tale signs of it having been in humidity and dampness so I think it may have been a momentary loss in one of the vertical pots as I turned the vertical linearity pot and was alittle stuck at first and I still have boost voltage and all the vertical pots check out fine and vary with turning them. That 24 meg measures 30.59meg slightly high.

at 20%, which is what it was most likely what it was made as, 28.8 would be the top, so 30.59meg is just a hair over, prob nothing to worry about.

[timmy]

The other resistors check good except for that 24 meg all I have is a 22 meg that measures 25meg so I may insert it in there with the one lead clipped. So I checked the other couplets and the both measure 115k while it should be up around 150k so I don’t know what’s with that.

[Yamamaya42]

Originally Posted by timmy

The other resistors check good except for that 24 meg all I have is a 22 meg that measures 25meg so I may insert it in there with the one lead clipped. So I checked the other couplets and the both measure 115k while it should be up around 150k so I don’t know what’s with that.

or, you can hook this across pins 1-2

588-SM108031006FE Mouser part #

100 meg 2 w resistor.

the 2 in parallel = 23.424458228 meg.
or just leave it, it should be OK for a while.