Videokarma.org

Go Back   Videokarma.org TV - Video - Vintage Television & Radio Forums > Solid State CRT Televisions

Notices

We appreciate your help

in keeping this site going.
Reply
 
Thread Tools Display Modes
  #1  
Old 09-04-2013, 07:30 PM
wa2ise's Avatar
wa2ise wa2ise is offline
VideoKarma Member
 
Join Date: Dec 2002
Location: USA
Posts: 3,147
Question my panasonic ct36L11e CRT TV set died

It's a big CRT set, 32 inch screen. Just died. When I try to turn it on the relay clicks, and about 5 seconds it gives up and clicks off. No TV sound or picture (though the CRT would not have had time to warm up anyway). Without removing the power plug, subsequent attempts to turn it on do nothing. Pull the plug and reconnect some time later, I get the 5 seconds as above and it gives up.

Before it died, the horizontal width was getting narrower, about an inch of CRT screen on the right wasn't getting any image, aka, was black. Been like that for months.

This set weighs more than I do, I'd guess, and that would make getting the back off really hard.

If it's likely just a bad power supply cap, I could replace that. If the horizontal output stage died, that likely will make me give up on it. What part failure does this sound like?

TIA
__________________
Reply With Quote
  #2  
Old 09-04-2013, 08:24 PM
radiotvnut's Avatar
radiotvnut radiotvnut is offline
VideoKarma Member
 
Join Date: Jul 2007
Location: Meridian, MS
Posts: 6,025
Sounds like a cap in the horizontal circuit failed and it eventually took out the HOT.
Reply With Quote
  #3  
Old 09-05-2013, 04:00 AM
Dude111 Dude111 is offline
Analogue is Awesome
 
Join Date: Oct 2009
Posts: 2,735
Im so sorry buddy!!

We love our TVs like crazy.....I hope you can get her going again
Reply With Quote
  #4  
Old 09-05-2013, 09:08 AM
zeno's Avatar
zeno zeno is offline
VideoKarma Member
 
Join Date: Mar 2013
Location: New Hampshire
Posts: 4,918
Yup sounds like the HOT shorted. You have several other
hurdles if it is.
What caused it.
Did it damage the power supply.

Big sets are a pain to work on unless on a bench with
space & lots of light. Also Sams doesnt list it ( got a chassis ##?).
The only things I remember with newer Pannys was HOT's,
the usual PC cons at hoz drive transformer & pin diodes.
If you go further post a few chassis photos to familiarize
us & maybe we can help.

It may be time to put it down sorry to say. You can get these
at Good Will etc for next to nothing. Just try to get an
older one from a big maker. I would stay away from Zeniths,
& NAPs. Sets before the late 90s wont be rebadged Chinese
garbage, more likely the real thing........

73 Zeno
Reply With Quote
  #5  
Old 09-05-2013, 10:21 AM
Zenith26kc20's Avatar
Zenith26kc20 Zenith26kc20 is offline
VideoKarma Member
 
Join Date: Apr 2009
Location: New Orleans
Posts: 847
Pincushion diodes and horizontal outputs were a problem on the CRT panasonics as well as power supply electrolytics and IC's.
Also, look around the power relays. Bad connections are a problem there.
While you are in there, look over the caps around the vertical IC and the vertical IC connections. They were problematic.
Can you post a picture of the chassis.
Also, is it the Prism or the TAU set.
The TAU had CRT troubles (went gassy quick) and power supply intermittants that was connections all over the circuit board.
Reply With Quote
Audiokarma
  #6  
Old 09-05-2013, 02:14 PM
wa2ise's Avatar
wa2ise wa2ise is offline
VideoKarma Member
 
Join Date: Dec 2002
Location: USA
Posts: 3,147
It's this model ct 36L11e Picture when we first got it.
I took a quick peek thru an opening at the chassis, the few big caps I can see don't look bulged. The back helps support the set, making it difficult to remove.
__________________
Reply With Quote
  #7  
Old 09-06-2013, 09:21 AM
zeno's Avatar
zeno zeno is offline
VideoKarma Member
 
Join Date: Mar 2013
Location: New Hampshire
Posts: 4,918
Not to worry. When you pull the back it will be a little more
front heavy so keep that in mind. Also if the speakers are on the back you gotta unplug them. Once off you can slide back the chassis &
do some checking. Zenith 26kc20 pointed out some other common
problems. Even if they are not the cause they should be checked
along with a good looking over for PC cons & swollen or discolored
caps. With the back off its also easy to move. Just hug the set
from the front & grab the edges to move. Just watch the neck!
Putting the back on agn you have to line things up but most the
time they fall nicely into place. Sometimes you may need a
second helper to tip the set a little.

good luck Zeno
Reply With Quote
  #8  
Old 09-07-2013, 02:15 PM
wa2ise's Avatar
wa2ise wa2ise is offline
VideoKarma Member
 
Join Date: Dec 2002
Location: USA
Posts: 3,147
I opened the back and pulled the circuit board. AFAICT, the HOT transistor isn't shorted, at least from emitter to collector. I measure 40 ohms both ways from emitter to base, after I pulled two wire jumpers that disconnect the emitter and the base from the rest of the circuit.. It's a 2SC5339 and I looked up the data sheet on line and it turns out it has a built in 45 ohm resistor between these points, so maybe it's not blown..

No cap looks by sight to be spilling its guts. And I tried resoldering the horiz output transformer terminals on the board, but the set still shuts down in a few seconds, as before.

A sticker on the HOT heatsink says: "serial number LE20210034 GP342". Other than that, I don't see any identifications.
Attached Images
File Type: jpg IMG_0267.jpg (146.9 KB, 27 views)
__________________

Last edited by wa2ise; 09-07-2013 at 02:57 PM. Reason: update
Reply With Quote
  #9  
Old 09-07-2013, 08:27 PM
zeno's Avatar
zeno zeno is offline
VideoKarma Member
 
Join Date: Mar 2013
Location: New Hampshire
Posts: 4,918
GP342 is prob the chassis # G342 is also shown on the label
on the tuner. Still no joy on a Sams. I know this was used in
27" + sets. Monday I will comb through my Sams & see if I
can come up with a similar chassis. I have done them & there
was something abt the power supply I just cant remember.
Also note the vert looks like its been running hot. See
discolored board in front of FBT near TAC switches.

For now the HOT is good. 99.9% of failures is total short E-C-B.
1) with it still out be sure there is no short on the PCB E-C.
2) put the HOT back in. Hang a meter in on HOT E-C DCV.
turn set on & see if the V comes up to 130 +- before
shutting down.
This will tell a lot, let us know & we will take it from there.......

73 Zeno
Reply With Quote
  #10  
Old 09-07-2013, 11:28 PM
Findm-Keepm's Avatar
Findm-Keepm Findm-Keepm is offline
Followin' the Rules...
 
Join Date: Jun 2007
Posts: 2,857
Somebody he manual up on ScribD:

http://www.scribd.com/doc/45748723/CT-32D11

Some of those Panasonics had a mod kit for the HOT - if the 2SC5339 HOT is Q551 and is bad, you'd also change a couple of resistors. Seems like somewhere on the web would be a reference to it, but I'm having no luck.

Really a reliable chassis - usually we'd see them with the antenna connector pulled out or a lightning strike would get the set. Not too many in for other gripes.

Cheers,
__________________
Brian
USN RET 22YRS (Avionics/Cal)
CET-Consumer Repair and Avionics ('88)
"Capacitor Cosmetologist since '79"

When fuses go to work, they quit!
Reply With Quote
Audiokarma
  #11  
Old 09-07-2013, 11:39 PM
wa2ise's Avatar
wa2ise wa2ise is offline
VideoKarma Member
 
Join Date: Dec 2002
Location: USA
Posts: 3,147
Thanks all for your help, but it seems the flyback developed an internal short. So I'm gonna give up on this set and will scrap it for parts.
__________________
Reply With Quote
  #12  
Old 09-08-2013, 01:50 AM
Dude111 Dude111 is offline
Analogue is Awesome
 
Join Date: Oct 2009
Posts: 2,735
I understand your frusteration....

Its too bad you cant discover WHERE the short happend
Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 11:03 PM.



Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2026, Jelsoft Enterprises Ltd.
©Copyright 2012 VideoKarma.org, All rights reserved.