Author Topic: 27ZP4 picture tube  (Read 373 times)

electra225

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27ZP4 picture tube
« on: August 01, 2018, 02:00:48 PM »
It's final.  The picture tube in my Stereo Theater is probably too weak to produce a decent picture.  I have had it on the tester for two days.  My B&K tester wants 300 as a minimum good reading.  This thing struggles to get to 150.  I can increase the filament voltage to 8.4 and it will BARELY make the "Good" range.  I'm going to have the picture tube out of the cabinet anyways, so I had just as well put a known good one back in.  I would like to have a NOS picture tube for this thing.  Although I don't know this, my guess would be that there were not that many 27" black and white sets sold, so the chances of finding an odd-ball 27ZP4 might be pretty good.  There was a member on here parting a Stereo Theater last fall, but I have misplaced his contact information.  I'm not in a big rush, but the search should probably start now.  If I can't find a NOS one, anything that tests good and will work is acceptable.
I'm great at multi-tasking.  I can listen, ignore, and forget all at the same time.

SeniorSteve

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Re: 27ZP4 picture tube
« Reply #1 on: August 01, 2018, 06:41:32 PM »
I see test equipment for CRT's called rejuvenators, I was wondering if you can find someone that has one, and is willing to try it on your tube.  If it's as bad as you say, you can't hurt to try.
My 2cents.
Steve

electra225

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Re: 27ZP4 picture tube
« Reply #2 on: August 01, 2018, 10:35:58 PM »
My tester has a "rejuvenate" selection on it.  I have never done that before.  I always figured it was like "mechanic in a can."  Wonder if that really works?

According to what I have read, perhaps my next step should be to power up the TV and see what happens.  Since I am going to have the tube out anyway at some point, I thought it best to start the hunt now.  How long would rejuvenation last if I did it successfully?  Is it permanent?
I'm great at multi-tasking.  I can listen, ignore, and forget all at the same time.

SeniorSteve

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Re: 27ZP4 picture tube
« Reply #3 on: August 02, 2018, 08:27:29 AM »
The tube may show up as weak, but may provide an acceptable picture.  Before hitting the "fix" button, I'd get it running first and then decide if a new CRT, or rejuvenation is necessary.  Sometimes the CRT test equipment fixes them, and sometimes they finish off the tube permanently (in not a good way).  I'm hoping your tube will work just the way it is.

electra225

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Re: 27ZP4 picture tube
« Reply #4 on: August 03, 2018, 04:55:44 PM »
Steve, I believe your advice is spot on.  The more reading I do, the more it appears I may be getting ahead of myself.  Searching early is not all bad.  This may be a hard to find tube.  I need to do more troubleshooting.  Thanks for your input.
I'm great at multi-tasking.  I can listen, ignore, and forget all at the same time.

walyfd

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Re: 27ZP4 picture tube
« Reply #5 on: August 03, 2018, 05:53:44 PM »
No harm in looking.  How many good ones are left?  One or even 2 come along, grab them.  Look how long it took to find the console itself...

electra225

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Re: 27ZP4 picture tube
« Reply #6 on: August 03, 2018, 11:20:28 PM »
Mine is the only one I know of that anyone has attempted to restore.  Most are taken apart for the amplifier.  Surely there are some spare CRT's laying around.  Your point about how long it took to find the ST is well-taken. 
I'm great at multi-tasking.  I can listen, ignore, and forget all at the same time.

AMP82-01-00

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Re: 27ZP4 picture tube
« Reply #7 on: August 09, 2018, 09:12:01 PM »
I wouldn't get too hung up on what a tester tells you. I had a 24 inch black and white TV that tested to the top part of the bad section. But yet the picture was perfect.


It's worth at least trying it out
David        "If it ain't interesting, its really just boring"

TC Chris

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Re: 27ZP4 picture tube
« Reply #8 on: August 09, 2018, 09:22:17 PM »
Mine is the only one I know of that anyone has attempted to restore.  Most are taken apart for the amplifier.  Surely there are some spare CRT's laying around.  Your point about how long it took to find the ST is well-taken.

The take-apart-for-the-amp crowd are not going to save a CRT.  It'll get pitched into the landfill on the next trash pickup day.  You need a hoarder like me who figures, "some day, somebody's gonna want that."  I have so much good junk....  Too bad there's not a national version of our local Freecycle.  Maybe try asking on ARF.

Chris Campbell