Admiral Roundie Something explodes

[tvcollector]

My Sencore has always made the little noise when it starts up, has done it on all tvs i tested it with. I don't know if its a whistle noise, it just makes a little noise, just dont know what to call it, or how to explain the noise.. I bought it off Ebay about six months ago. I thought the little noise from the Sencore is normal, it seems to perform tests fine, unless it's giving me incorrect read outs i don't know about.

How would i fix the shorted leads? or get the cap off to wire/solder the leads or to check to see if they are not broken?

[DaveWM]

pretty sure it uses a switching power supply for the filament, that is what you are hearing, mine does it to, its pretty hi pitch, I would guess in the 10-12khz range.

[bandersen]

Originally Posted by tvcollector

... How would i fix the shorted leads? or get the cap off to wire/solder the leads or to check to see if they are not broken?

You might find this thread useful: http://www.videokarma.org/showthread.php?t=248393

[tvcollector]

I kinda figured it was a normal noise.. Did you see the pictures, any suggestions? there's a company in south Carolina that rebuilds CRTs, and that hawk eye guy is retired.. I don't know how much the cost is to ship rebuild and ship back..

Or is there a way to get behind the socket cap to check the leads? I downloaded a file off the internet thats a schematic for that tube..

[tvcollector]

Ok, interesting looks like that cap comes off in two pieces with pins under the first part.. Thats where i need to get to, and it looks like a task and it's self

I may just get it rebuilt. I tried hawkeyepicturetube.com he's retiring and doesn't want to rebuild anymore, but is looking into another source for that one

and now im trying wmicronics.com they have to get back to me..

I don't how expensive it is to have it rebuilt or get a rebuilt one from any of these guys.. If it's too much, than i will forget about that..

[Eric H]

The cap should come off as one piece, unless it's broken of course.

If it's already loose you should be able to heat the pins with a hot soldering iron, one at a time while gently pulling it on teh side where you are heating it, a little at a time.

if you have a really hot iron 25 watts or better you can probably heat two pins at a time but just be very gentle not to break any of the wires or snap off the fragile Glass nipple that's underneath it.

To check for a white getter you will have to remove the tube from the chassis, it'll be in the area under the Yoke.
Some tubes have a Getter near the high voltage connection on the side of the tubes bell, if you can see a white patch there the tube's done.

If you remove the tube use extreme care not to rip the cap off as it goes through the Yoke, they can be tight sometimes, a little heat from a hair dryer or heat gun can help it go through but don't hit the tube with the heat gun or you could shock it and cause it to break.

[compu_85]

When I repaired the tube base on my set I used a very small butane torch. I was able to quickly heat all the pin ends and pull the base off. I also used the torch when I re-soldered it.

-J

[tvcollector]

I will have to try that tomorrow when i have spare time.. I'll report back..Thanks for the info..

[tvcollector]

Well i actually went ahead and did it, using a de solderer that has a pump to suck out the solder, did it slowly as the cap pulled off little by little, well all the connections are there and none broken.. plus i notice the phosphor on the tube front is coming off as i can see a solid circle in the middle of the tube where light is coming through from the lamp i have in back of the set.. So i guess this Tube is DEAD..

[Boobtubeman]

Not nessasarily... could be just a phosphor burn on the face...

[tvcollector]

Hum maybe, i had my clip on lamp facing right at the neck as i pulled off the black cap, only time i noticed it, i pointed the lamp slightly at a different angle and its not noticeable any more.. Well all the wires that went into the soldered pins, look to be fine, so what should i do next?

[DaveWM]

test it again this time clipping on to the wires.

[tvcollector]

I thought that may be the next thing, just wanted to make sure.. I'll report back Tomorrow....

[bandersen]

Good luck. Be very careful not to stress those wires with the weight of the Sencore UA clips and cable.

[jr_tech]

Originally Posted by tvcollector

there's a company in south Carolina that rebuilds CRTs, and that hawk eye guy is retired.. I don't know how much the cost is to ship rebuild and ship back..

You might want to check out this old thread(s) about wmicronics:

http://www.videokarma.org/showthread...ight=micronics

jr