Panasonic TV turning on and off

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venom96737
Panasonic TV turning on and off

I have a panasonic CT-32S20U that will turn on and works just fine but then shuts off.  The time in which it shuts off varies but it was taking alot longer for it to do it at first say 2 hours or so now its around 5-10 minutes.  I have opened the set and see that a corner on the mainboard is actually broke off right above where the screw hole is on the HOT side.  Right above the bracket that says it is LINE but i dont think there is a trace in this piece if there is its a small piece.  Some odd things that happen when this occurs include:  when the set comes back on there is no need to touch the power button it just pops on also the menu is displayed when it comes back on.  You have 2 choices when it shuts off you can either wait 20-30 minutes for it to come back on itself OR you can hit the back of the set around the power cord and a/v inputs and it will come back with some work.  I have checked the power cord for shorts also checked the solder joints on the board all seemed fine.  Can anyone tell me what my next move should be besides to the dump?

Ron.M
  venom96737:  1st, Thanks

  venom96737:  1st, Thanks for your reply in the other thread...
In reply to this thread:

I don't know how adept you are with TV repairs...I have OVER 45 years....
I'm not familiar with your model TV ....That doesn't mean I can't help you ...
Experience tells me from what you said , that you probably DO have a bad connection OR solder joint...Possibly a cracked trace...
I would take a VERY close look at that cracked area....Oftentimes the crack can extend unseen & cause a hairline break in the foil...Can be a nightmare to find..But there are ways to nail it...
Also since you found 1 crack , there maybe another...(Set may have been dropped or josseled)
Look for a power supply transformer  & check VERY closely at the connections & solder joints around ALL pins....
Also , check ALL pins & connections around the flyback...On a lot of sets , pulses from the flyback feed other circuits , including the micro...Hope this helps....

PS:  Do you know what year it was  made ??

venom96737
NP on the the other post I

NP on the the other post I work as a network admin and have been doing computer repair for years so if you find that the program doesnt open them just get back to me and maybe you can email me one of the files and i'll get you something that can open it. The TV in question was manufactured in 1996 I can only find a copy of the manual which is here http://www.retrevo.com/search/v2/jsp/mytrevo/myTrevo.jsp?page=man
All the service manual are purchase only.
I like you was thinking either a variation in voltage or heat or cracked trace or solder connection. My TV repair abilities are limited but i'm starting to get a grasp on the situation. One question when the board says its hot is it hot from the power supply or is it hot from CRT and which if any or both should be discharged before touching that side of the board. The TV has been unplugged for a awhile but I know that cap can hold voltage for ALONG TIME. Well the TV had been dropped as you say but i think what actually caused it to start acting in this manner was a lightning strike I looked for obvious show of damage from a strike like this IE bulging or leaking caps, blown fuses, blackened solder connection, and so forth. Unfortunatly I found non of this so I was thinking maybe the flyback had been damaged and is just in a degenerative state if that makes any sense just really couldnt figure out why the menu would come on eachtime the set comes on after it turns itself off thought maybe that could help lead to a culprit.

Ron.M
venom96737;  "Houston , we

venom96737;  "Houston , we have a problem"...Actually a few probs...
1st..in reply:
The Daemon file did not work...It is for ISO files & the like...I can NOT email you the files because I can't get them off the CD to desktop...And they are hidden with that G.D.   Roxio icon crap...(UDF)..Can not penetrate it...
I checked your link to Retrevo & there are no manuals saved...

Now about your TV...
Your limited repair abilities are going to be a problem...But we'll try to help...

Where it's printed on the board "Hot" , that means that area is connected DIRECTLY to your AC line
voltage...ie; 110 volts AC....DO NOT TOUCH THAT area when the set IS PLUGGED IN...Unless you KNOW what you are doing...It is NOT "Hot" from the CRT...
Discharging:  Be VERY , VERY careful with this step !!....With the set UNPLUGGED ONLY....There is a RED wire going from the top of the flyback to the side or top of the CRT....Connect a jumper from chassis ground (First) (NOT "HOT" ground ) , then attach something like a metalic probe to the other end (DO NOT grasp this end as you WILL get bit) & CAREFULLY slide it under the rubber disc to the center...Keep your fingers as far as possible from the rubber as you do this...This voltage IS VERY HIGH , about 30KV..(That's 30,000 volts) You will hear a pop or crack...Do this a couple of times to make sure that it's fully discharged...CRT's have been known to hold their charge for YEARS...

Power supply:
Look for large lytic caps , usually in the 100-330mfd range...Connect your jumper first to ground (-) then to the +...Do this a couple times to each cap you find to make sure they're fully discharged...
Now it should be safe to look for other cracks...

I seriously do NOT think that the lightning strike is the cause of your problem...Usually when that happens you have blown fuses and / or serious power supply dammage..The chances that the flyback is dammaged are slim to none..& slim left town...

The reason the menu comes back is due to the fact that the micro is reseting itself...This is why I think you have another crack somewhere...Check the top for cracks as sometimes they are elusive & difficult to see on the bottom...Especially the areas I mentioned earlier...

  Let us know how you make out....Later....

Ron.M
venom96737;  "Houston , we

venom96737;  "Houston , we have a problem"...Actually a few probs...
1st..in reply:
The Daemon file did not work...It is for ISO files & the like...I can NOT email you the files because I can't get them off the CD to desktop...And they are hidden with that G.D.   Roxio icon crap...(UDF)..Can not penetrate it...
I checked your link to Retrevo & there are no manuals saved...

Now about your TV...
Your limited repair abilities are going to be a problem...But we'll try to help...

Where it's printed on the board "Hot" , that means that area is connected DIRECTLY to your AC line voltage...ie; 110 volts AC....DO NOT TOUCH THAT area when the set IS PLUGGED IN...Unless you KNOW what you are doing...It is NOT "Hot" from the CRT...
Discharging:  Be VERY , VERY careful with this step !!....With the set UNPLUGGED ONLY....There is a RED wire going from the top of the flyback to the side or top of the CRT....Connect an insulated  jumper from chassis ground (First) (NOT "HOT" ground ) , then attach something like a metalic probe to the other end (DO NOT grasp the metal on this end as you WILL get bit) & CAREFULLY slide it under the rubber disc to the center...Keep your fingers as far as possible from the rubber as you do this...This voltage IS VERY HIGH , about 30KV..(That's 30,000 volts) You will hear a pop or crack...Do this a couple of times to make sure that it's fully discharged...CRT's have been known to hold their charge for YEARS...

Power supply:
Look for large lytic caps , usually in the 100-330mfd range...Connect your jumper first to ground (-) then to the +...Do this a couple times to each cap you find to make sure they're fully discharged...
Now it should be safe to look for other cracks...

I seriously do NOT think that the lightning strike is the cause of your problem...Usually when that happens you have blown fuses and / or serious power supply dammage..The chances that the flyback is dammaged are slim to none..& slim left town...

The reason the menu comes back is due to the fact that the micro is reseting itself...This is why I think you have another crack somewhere...Check the top for cracks as sometimes they are elusive & difficult to see on the bottom...Especially the areas I mentioned earlier...

  Let us know how you make out....Later....

venom96737
cant get them off the cd??

cant get them off the cd?? That makes no sense at all there is no reason it shouldn't allow you to take them and move them to the desktop. The reason you are seeing that icon is because someone at one point or another told your computer that roxio will open a file with w/e extension it has on the end of it. If you could right click one of the files goto properties and tell me what it says for file type i might be able to narrow down the extension for the files then you just have to open it with the correct program. Now back to the tv I will try to check all that tonight thanx for the help in pointing me in a few directions I will post an update as soon as I can.

Ron.M
venom96737:   Here's the deal

venom96737:   Here's the deal....

Roxio gives my computer problems...I can NOT find the updates reccomended at their website to fix the program...They want me to buy their program instead....

When I try to open the files there's an icon for "udfrinst.exe" with a large "UDF"....That appeared after I let Roxio install...Was NOT there before...When I right click that icon , I get the option to delete it...I would like to delete it to see if my manual folders re-appear , BUT , I'm afraid to in fear of also losing those folders...

When I right click on it , there's an option to send to desktop...All I get is that G.D. Roxio program..& no files !!! So I can't give you the file extension data...

I think that Roxio is part of Win XP Pro...I have deleted it many times & it keeps coming baaack...

Too bad there's not a way for me to upload an image to show you what I'm getting...

Talk later....

venom96737
There we go thats what I

There we go thats what I needed the UDF part sorry missed it in the first part that is the format that the files are in DONT DELETE THEM here you go this should do the trick http://ftp.ucr.ac.cr/Windows/adaptec/directCD/udfreaders.html#win

venom96737
Well now I have to see if

Well now I have to see if your drive is supported though what is the make and model of your cd rom drive?

venom96737
here this will fix it ignore

here this will fix it ignore the first one its for win 98 computers this one is the one roxio uses. What happens is roxio burns it in udf format just another reason not to use roxio.

http://www.driverguide.com/boards/cdrom7/2303.html

Ron.M
  venom96737:  I went here:..

  venom96737:  I went here:... http://www.driverguide.com/boards/cdrom7/2303.html & don't know which link to download from....Undecided.....

FYI: I tried to delete UDF & it can't be done...I have 3 CD's of files , so if I screwed up 1 , no great loss...But , luckily that didn't happen....

My CD-ROM drive is ==>  LITE-ON   LTR-12101B....I got this from properties of CD thru "My Computer"...I know there is more specific info in the "Hardware Manager" but I can't find it...Forgot where it's at...Surprised

I'LL be offline til tomorrow afternoon...Have to get up at 5:00 AM for a half days work...Hope to see ya sometime then...Smile.....

venom96737
here you go I didnt realize

here you go I didnt realize that post didnt have a direct link to it lol http://www.roxio.com/enu/support/udf/software_updates.html

Ron.M
venom96737: 

venom96737: 

Bad news...I downloaded the update...
Then I put in the CD , clicked on the "UDF" icon to install the Roxio deal, then I ran the update program , & re-booted...
When I tried to open the files , I got Zilch , Nada, etc...All I got was a graphic saying the my Roxio was fully updated...No files....

Methinks that the ONLY thing on those CD's is that Roxio program...
I'm giving it up as a lost cause....
If those files are still there , so be it...I give up....

Many Thanks for your help....

Let me know how you make out with your TV...Even tho it's 13 years old , if the CRT shows a good pix , it's probably worth fixing...Your call....

Later.....Cool....

venom96737
Well sorry to hear that BUT

Well sorry to hear that BUT you could linux to see if the files are there :D bootable copy here http://www.knoppix.com/ just click the download button and find click ftp on one of them and it will start then burn the image to a cd. If its burned correctly it will boot right up to linux and you will be able to see whats on the cd just another option for ya. I took another look at the tv and the aforementioned crack is right above the flyback and the rest of the board looks solid so I would bet this is cause of the error so I'm going to discharge the crt so the flyback doesnt give me a charge and then either solder in a jumper to complete the circuit or repair the baseboard and the trace havn't decided yet, but the only problem with that would be trace on the broken piece is very small and i dont think I will be able to scrape it enough to get a good repair. Also when it broke off it took some of the trace off the board with it so there is a bit of hangning trace so im thinking jumper wire would be the best way to go what do u think?

Ron.M
venom96737:   1st;...I've

venom96737:   1st;...I've given up on those files...Thanks anyway...

Now to your TV:..Before you start:...I really would like to see an image of the cracked area so I can give you detailed info as to go about making accurate & durable repairs...Some of those trace lines could be quite skinny & there is a "trick" to making permanent repairs...This website doesn't have an upload feature to upload anything...Do you have ANY way to photo the crack(s) & perhaps send me an email with an attachment ??  If so , I will PM you with my direct email address...

Also, I'm a little confused about  when exactly that "little" piece broke off...& with it broken off are you getting the same symptoms & /or did the symptoms change in any way ???....What I'm trying to find out here is , is there any trace on the piece that broke off & did it sever any lines on the main board  ??

You said:... "I don't think I will be able to scrape it enough to get a good repair."...There IS a way to do that WITHOUT scraping the foil...I will be glad to enlighten you...

  You said:..."I took another look at the tv and the aforementioned crack is right above the flyback. "...Is this another crack ??  I somehow , for some reason , thought that the piece that broke off was a corner of the main board & not inside the perimiter of it...BTW , SAVE the piece !!

Please reply to ALL of this post so we can procede in the right direction....THANKS...Later...Cool

venom96737
I can take picture just pm me

I can take picture just pm me the email address thats not a problem. I am getting the same symptoms just now that it broke off completly its faster the tv doesnt stay on as long. See before it completly ripped off the trace was still holding it onto the board like a flap it will become clear once I send you a pic. Yes it was the corner of the board but the flyback is directly below the corner of the board and the traces lead past the flyback once again it will become clear once I can send some pics and yes there is a small bit of trace on the piece I have and also trace hanging out on the main board where the piece used to be. Yes I would love to hear a different way to solder it back without scraping the foil. Finally yes I had to search high and low to find the piece but I am saving it :D

Ron.M
venom98737:...See PM...Ron.M

venom98737:...See PM...Ron.M

robf
Hi...

Hi...

 I have a 27" panasonic with very similar symptoms and could use some help too..

 I can start a new thread if that would be easier... 

 It's a CT 27 D10B model, made in 2000.

Symptoms:

Will randomly power down for 5 to 20 minutes then come back up for 1 min to a couple of hours. Does't seem to matter if it's just turned on or been running for hours...

There is usually an audible "click" when it goes on  or goes off.

I removed the back cover and inspected the PCB. I don't see anything unusual such as burnt areas or parts. THe small fuse is OK. The TV has not been dropped or jarred while I've owned it (since new) and worked fine for the first 7 years or so. It's gradually getting worse now. Used to only happen once or twice a day, now can't go an hour or 2  with out it happening at least once.

If I can't track down the problem is it worth trying to replace the circuit board assy?

 Thanks!

Rob

Ron.M
robf:...venom96737 should be

robf:...venom96737 should be online later...He will probably let you know whether or not to start a new thread....Wink

About your TV: I personally can not be of much help to you as it would require a "hands on"  from me...There are several causes to your problem...Could be bad PC connections , Regulator IC , etc....Other tech's visiting this thread may be able to help you...

You said:==>"If I can't track down the problem is it worth trying to replace the circuit board assy?"
The price of the board versus replaceing the set is going to be your call...
A way to find out the cost of the board is to "Google" the board # (or chassis#)  using quotes...You will get a list of sources for the board...Shop VERY carefully as there are scam artists out there...You can also try "ebay"...Just enter your board # in the search box...You may or may not get a listing for your board...
Another company is "PTS"...They ARE reputable , but a bit pricey..
I hope this helps....Sorry I can't help you further...
Best of luck...Smile

robf
OK, Thanks for your response

OK, Thanks for your response Ron!

robf
OK, I do see some signs of

OK, I do see some signs of overheading on the board, in two places... One appears to be in the "theral protector" area, and there is a large white 150 ohm resistor there so I suspect it's what's casing the problem.

The other area is nearby where there is a large part labled K3L5N at the "T801" site on the board, which has 2 rows of pins. On row is on the cold side and one on the hot. There are around 17 pins total. The offending part in that area, based on the area of worst heat damage appears to be a large white 47 ohm resistor.

My first thought is to try to add a fan to cool the area. Any thoughts as to why it's overheating?

Thanks,
Rob

venom96737
Ron you got mail and dont

Ron you got mail and dont worry your secret email is safe with me lol. If the pictures arnt what you need or you need more just let me know.

venom96737
Oh and about the thread I

Oh and about the thread I dont care if you can find help in here more power to you no need to make a new one.

Ron.M
venom96737 & robf:   1st...

venom96737 & robf:   1st... venom96737:

I got the pix...FYI:  I'm on dialup with an older Dell comp...It took 30 min's to open the file (approx 11 Mb)...NOT a complaint , just an observation...Thanks VERY much for sending them..

From the looks of image "0869" you did NOT sever any traces...So I wouldn't worry about jumpering anything..The broken piece is only a part of what remains on the board...Image "0869" shows the rest of it...It is part of a large pattern of which only a small piece is missing...Long story short , it's NOT your problem...

I'm going to send you an email with an attachment..In it you will see a board highlited by an arrow..This is your AV input board...What I'd like you to do is take a VERY close look at the connections on the main board foil side for bad solder joints...( NO offense , but do you know what a bad joint looks like ??...If not I'LL try to help..) If you can , I'd also like you to take a CLOSE look  at the connector (the one that plugs into the main board) connections ON the AV board.....You MAY have to remove it from the chassis..If you are uncomfortable in ANY way , do NOT remove the AV board...Since the micro "Talks" to this board , it "could" be at fault...Let me know what you find...

robf: The discolorations you appear to be talking about could just be from normally hot parts over 8 / 9 years of use..The 150 ohm resistor sounds like it's a B+ regulator resistor...They normally do run hot...& discolor the board over time....
Since I'm not very good at memorizing schematics , I'll google "K3L5N" to ID it..
A fan is NOT , repeat NOT, the solution...NOT even a workaround !!!
I'm concerned about that "Audible Click" you hear....
You possibly could have bad PC connections as well...

The 47 ohm resistor is a mystery without seeing it &/or a schematic...Could also be bad connections there too..

Before we go any further...I need to know a bit about any TV repair experience you have...
PM me with all the info you are comfortable giving me about your technical abilities....& be honest....
And I will try to help you as best as I can...Later folks...Cool

EDIT: OK I'm back...I Googled "K3L5N" & it's a smps (Switch Mode Power Supply) transformer....Of no concern right now as they seldom go bad...Later

Ron.M
TO all:  robf has given me

TO all:  robf has given me permission to post a private email conversation regarding his  TV & repair abilities...Here it is UNALTERED:

 
 

robf:   Thanks for your honest reply...
You said:..==>..""I've been running the TV all day with a fan behind it, with no problems. Not a good idea? Why not? It's masking some serious problem? ""
YES , You definitely ARE masking a problem that can & WILL get worse & could cause MAJOR dammage...Very similar to placibo meds..You may feel better , but the illness WILL worsen...

You said:==>..""I don't have any experience with TVs. I know they have some very high voltages and I assume they are potentially enough to kill...""
The high voltages HAVE killed people... Do NOT assume that just because the TV is off & unplugged that you are safe...You ARE NOT...I've seen cases where some TV's have held their voltages ( especially the high voltage to the CRT ) for over a YEAR !!!

Based on your info , (using a fan to cool it down)..it IS a thermal problem that requires some expertise to locate the problem part(s) causing it to shut off..(Involving the use of freeze spray , etc)....My experience is suggesting that you may have a bad lytic cap(s) in the power supply , could also possibly be bad connections...

You said:==>..""What I was hoping was that I could save some money in troubleshooting costs and could hopefully ID the problem and have a shop make the necessary fix.
I see new boards at PTS for around $180 which could beat buying a new TV depending on how much it would cost me to have it installed.""
If you get the board from PTS , do NOT expect to just put it in & everything is going to be hunky dory (OK)...Many times you (or a tech ) WILL have to make "Factory Menu" adjustments to match the board to your TV...

My sugesstion would be to take the set in to a good , honest & reputable TV shop for a repair estimate...Due to the nature of this problem , a home call , in this case would be a waste of money..They'd have to take it in anyway..Be wary of those "Free estimate guys..(<== another long story)...Unless you can trust them...In my experience , the repair for this set WOULD be far LESS than $180.00...(in my area)...Your call...
With your inexperience , I would NOT reccomend you do it yourself....
Good luck & best regards...

Rob:...I would like to post most of this reply to the thread....Including from your PM...May I have  your permission to do so..PM me either way....
 
Here is part of the email he sent me:

Hi Ron,
Yes, I know there are high voltages which are present when the set is unplugged. That's why I don't want to try to repair it myself...

Sounds like I may be able to get away with a fix at a reasonable price at a good shop. I'll do some calling around. 

Sure, you have my permission to post this PM...
Thanks very much for your advice. It's very helpful!

Best regards,

robf: Please let us know what happens...Thank you very much...Ron.M....Laughing

 
Ron.M
TO all :This is an OOOPS!!..

TO all :This is an OOOPS!!...Somehow I got a double post...SORRY about that....

venom96737
Hey sorry for the LONNNNNG

Hey sorry for the LONNNNNG delay on response had some issues pop up had to take care of. First sorry for the pics didnt even think about the size just uploaded them my fault. Next I actually had time to take the board out and look at it and found where the problem is. Its a dry socket on the board were the yellow cable plugs in coming from the tube. I already have unpluged everything to the board and will be fixing it this weekend. Thanx for taking the time to look over this Ron M.

Ron.M
venom96737:...

venom96737:...

You said:...""Thanx for taking the time to look over this Ron M.""
You are MOST WELCOME....Smile
I'm not sure what you mean by "dry socket"....I'm guessing it's what I know as "Cold solder connections"...Either way , I hope that solves the problem...
I'm also a little mystified as to "why" that would turn the set off & then back on with the "menu" displayed....Surprised
Anyhoo , please let me / us know how it comes out , by a post in this thread &/or a PM to me...

Later......Ron.M.....Cool..........

venom96737
Well it mystified me also and

Well it mystified me also and as it turns out this didnt fix that at all. It did slow down the condition IE it taks longer before it turns off also you can just tap lightly on the back of the set now and it will turn back on as opposed to before where it was getting harder and harder to turn back on. If you allow the tv to turn itself back on like dont tap on it thats the only time the menu will display if you tap it back on the tv will just start playing with no menu pulled up. So i guess im going to continue looking see what i can find I notice that you have to tap next to where the power cord goes into the set for it to come back on.

Ron.M
venom96737:

venom96737:
Suggestion:....Get a GOOD strong magnifying glass & search the ENTIRE main board for bad connections & CAREFULLY re-solder ANY suspicious ones....Especially the power supply area...Make sure you discharge ALL power supply caps...(Leave the set unplugged for an hour or so..This will help bleed off some voltages)
Tapping the board can mislead you...Especially if you are inexperienced...
Let me know what you find...

venom96737
Well i looked it over and

Well i looked it over and found that d810 and R812 had some connections that didnt look 2 good so imma try to fix those this weekend the washing machine broke when i was looking at it this time so we will see what happens with this.

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