Admiral Roundie Something explodes - Page 4 - Videokarma.org TV - Video

DaveWM · #46 02-03-2011, 11:22 PM

I have found that a "bad" tested B&W can ofter produce a pic, not great but good enough to at least trouble shoot the set. Then when you get a backup CRT that is good, thats when you give the rejuv a try. I have used the CR-70 rejuv and had good luck with it, but again why mess with it until you at least know how the CRT looks in operation BEFORE trying to improve it.

Same with Color CRT, even a weak gun is not the end of the world, you can do a lot with the bias and gain adjustments to get a decent pic. Back when you could just get a new CRT then fine rejuv, but now I take a much less agressive approach.

tvcollector · #47 02-03-2011, 11:22 PM

Dave some of those pins i notice don't hook all the way around the pins on the CRT, so that could be the problem there

DaveWM · #48 02-03-2011, 11:24 PM

yea you should be sure the pins are clean and you are getting a good connection on the CRT.

I was talking about the connector that the adapter hooks to the tester with, its a small plug with a lot of small pins. just make sure none of them are bent so when you attach, they will be connecting.

tvcollector · #49 02-03-2011, 11:31 PM

oh ok, gotcha... yup the cut off is below the bad levels still, sometimes when i turn it on the needle moves enough to touch the red

tvcollector · #50 02-04-2011, 02:59 AM

Comes to find out the plastic neck was twisted by someone before causing the tube to short out, so now im on the hunt for a 12LP4..Anyone have one? I checked Ebay and looked on goggle, nothing comes up for sale..

***Eric H*** · #51 02-04-2011, 04:52 AM

Sometime the wires inside the pins come unsoldered and reheating the pins with a soldering iron and applying a little dab of solder will fix it.

If it's been twisted and shorted it can be fixed as long as none of the wires have been broken off flush with the glass, even then it's sometime possible to make a repair.

jeyurkon · #52 02-04-2011, 07:23 AM

Quote:

Originally Posted by tvcollector

Comes to find out the plastic neck was twisted by someone before causing the tube to short out, so now im on the hunt for a 12LP4..Anyone have one? I checked Ebay and looked on goggle, nothing comes up for sale..

Just keep an eye open. One'll show up.

tvcollector · #53 02-04-2011, 09:31 AM

I think i would have to get the plastic piece that the pins come out of off, i think some are broken off, but i can't really tell, unless some how i can get that off the neck to where i can see whats coming out of the glass, to see what i can re solder...

DaveWM · #54 02-04-2011, 09:45 AM

I recommend you leave it be, after you get the set recapped and all seems to be working, if nothing on the CRT, then check the anode for HV, and the other pins for correct voltages. If still nothing then you have little to lose by messing with it. I would start with the heating of the pins and some solder on the end of the pins (it should wick in). the more you mess with the base the more likely something will break, pretty much the way it is with all 60 year old parts.

tvcollector · #55 02-04-2011, 09:49 AM

Dave, I've tried that..

tvcollector · #56 02-04-2011, 10:01 AM

I did the cut off test and emissions test again last night about an hour after the first tests, with out any attempt to rejuv, while doing the cut off and emission tests again the tube went completely out and the Sencore stopped making the whistle sound of it firing up the tube. So my guess is the tube was either very week to begin with or one or more connections behind the pins are loose or not making anykind of contact, so basically i have nothing to loose with the tube now..

So now i have two choices.. Attempt to fix this one or buy a good one, and just have My friend restore the TV with a good tube that i would purchase..

DaveWM · #57 02-04-2011, 10:33 AM

maybe it went to air and the filament burned out, I dont recall that tube but can you see the getter (looks like silver deposited on the side of the neck), if its white then you are done, check the 1and12 pins for continuity, should be a few ohms max. Guess you dont have a test CRT for the set (they are small crts that self focus and just used for testing).

tvcollector · #58 02-04-2011, 10:49 AM

I just looked and i don't see any white or anything that looks to be burned out.. I took two pics, so maybe they would explain anything better. I dont own anyother testing Equip other than the Sencore

kx250rider · #59 02-04-2011, 12:37 PM

That's almost a guaranteed disaster to plug in cold-turkey. Likely no serious damage, as long as the power transformer didn't get left on long enough to burn up. That would take several minutes, and you'd probably have blown the house circuit breaker. You probably lost a few capacitors and the 5U4 tube, along with a B+ resistor or two.

Definitely the set needs to be completely re-capped, and then troubleshot-repaired as needed.

Charles

jeyurkon · #60 02-04-2011, 12:57 PM

Quote:

Originally Posted by tvcollector

I did the cut off test and emissions test again last night about an hour after the first tests, with out any attempt to rejuv, while doing the cut off and emission tests again the tube went completely out and the Sencore stopped making the whistle sound of it firing up the tube. So my guess is the tube was either very week to begin with or one or more connections behind the pins are loose or not making anykind of contact, so basically i have nothing to loose with the tube now..

So now i have two choices.. Attempt to fix this one or buy a good one, and just have My friend restore the TV with a good tube that i would purchase..

Whistle sound? That's not good. Perhaps the CRT is gassy and the noise is from a discharge. Or, the Sencore is faulty, or you had it hooked up wrong. Or there were still some shorted leads because of the twisted cap.

My CR-70 has never whistled.

John