Panasonic Plasma TH-46PZ81B, 10 Blink SOS (Doesn't appear to be TEA1611T chips)

[tw2005]

Re: Panasonic Plasma TH-46PZ81B, 10 Blink SOS (Doesn't appear to be TEA1611T chips)

SO , did you change or remove the ceramic cap at all on either Module apart from replacing the TEA chip?

I'm thinking this may be short lived if you did not if it came back to life doing repetitive power cycles.

[ljnash]

Re: Panasonic Plasma TH-46PZ81B, 10 Blink SOS (Doesn't appear to be TEA1611T chips)

Hi tw2005,

Interesting question, I have an interesting answer (or possibly just a long answer)!

>> Short answer:

No I didn't replace the original ceramic bypass cap.

>> Long answer:

I did remove the ceramic cap from the MC301 board on the second P(MAIN) board to measure its capacitance and to check it wasn't shorted in some way. It measured just shy of 1uF (same value as people supply with repair kits) so I assumed it was ok and put it back.

As a last ditch attempt at using the original P(MAIN) board I did remove the bypass cap from MC301 (the one between TEA1611T pins 11 and 13), as I'd seen another blog where lots of people had been successful in repairing 10 blink faults by removing these caps (from both MC301 and MC201). My TV didn't get as far as starting MC201 so I decided just removing the cap from MC301 was sufficient as a test. As a result I could hear a distinct high pitch sound, indicating to me that the circuit had become unstable. As the TV still shutdown quickly I moved on to looking at the second P(MAIN) board I had.

>> Interesting bit:

Your question prompted me to google "Do MLCC degrade over time" and the top search result proved interesting. The site states that there is a "decrease in capacitance over time due to crystalline changes that occur" and that "The aging process is reversible. By heating...". Although it goes on to say that "Exposure to 150°C for 1.5 hours is sufficient" and whilst I clearly didn't cook it for that long, I did get the cap pretty hot with my hot air tool (could have been ~200-300°C).

You've left me with some doubt now as to whether I should be taking the TV apart again to swap the cap over or just leave well enough alone? It started up fine again this morning (first press of the power button) just like yesterday evening. I also wouldn't have though a reduction in capacitance would be an issue if others have had their TV's operating for 3+ years without one!? (http://blog.bronislavrobenek.com/pos...f-death-repair)

I'd be interested in hearing your thoughts, especially how you think repetitive power cycles are related to this cap. Thank you again.

[tw2005]

Re: Panasonic Plasma TH-46PZ81B, 10 Blink SOS (Doesn't appear to be TEA1611T chips)

Hi tw2005,

Interesting question, I have an interesting answer (or possibly just a long answer)!

>> Short answer:

No I didn't replace the original ceramic bypass cap.

>> Long answer:

I did remove the ceramic cap from the MC301 board on the second P(MAIN) board to measure its capacitance and to check it wasn't shorted in some way. It measured just shy of 1uF (same value as people supply with repair kits) so I assumed it was ok and put it back.

As a last ditch attempt at using the original P(MAIN) board I did remove the bypass cap from MC301 (the one between TEA1611T pins 11 and 13), as I'd seen another blog where lots of people had been successful in repairing 10 blink faults by removing these caps (from both MC301 and MC201). My TV didn't get as far as starting MC201 so I decided just removing the cap from MC301 was sufficient as a test. As a result I could hear a distinct high pitch sound, indicating to me that the circuit had become unstable. As the TV still shutdown quickly I moved on to looking at the second P(MAIN) board I had.

>> Interesting bit:

Your question prompted me to google "Do MLCC degrade over time" and the top search result proved interesting. The site states that there is a "decrease in capacitance over time due to crystalline changes that occur" and that "The aging process is reversible. By heating...". Although it goes on to say that "Exposure to 150°C for 1.5 hours is sufficient" and whilst I clearly didn't cook it for that long, I did get the cap pretty hot with my hot air tool (could have been ~200-300°C).

You've left me with some doubt now as to whether I should be taking the TV apart again to swap the cap over or just leave well enough alone? It started up fine again this morning (first press of the power button) just like yesterday evening. I also wouldn't have though a reduction in capacitance would be an issue if others have had their TV's operating for 3+ years without one!? (http://blog.bronislavrobenek.com/pos...f-death-repair)

I'd be interested in hearing your thoughts, especially how you think repetitive power cycles are related to this cap. Thank you again.

Well,my memory is a little vague but I think the very first one I played with has 2 blink error. repeated cycles it would turn on. Now I may be wrong but I mahy have soldered that cap and it worked, for a while. Maybe a couple of months then failed again and no longer could I fluke it to turn on with cycling.

Did what most were doing and got a kit with new TEA chips and caps. Decided to replace just the cap, Fixed. Also have reoved caps and also worked.

Just giving a heads up from experience but never gave it as much thought as you replied with. Bit of a no brainer if you're working on those modules, replace those caps

[ljnash]

Re: Panasonic Plasma TH-46PZ81B, 10 Blink SOS (Doesn't appear to be TEA1611T chips)

I'm going to take your advice

Far easier to change them now than when it's at my Sisters!

I've ordered some 0603 1uF X7R 50V capacitors. If I'm going to change them, might as well go for the best I can. I'll post to let you know how I get on.

Thanks again.

[ljnash]

Re: Panasonic Plasma TH-46PZ81B, 10 Blink SOS (Doesn't appear to be TEA1611T chips)

Just thought I'd share a final revelation. After 2 weeks of normal operation the TV failed again and just wouldn't start up. As I feared, working on the TV in my Sisters house wasn't exactly ideal!

Anyway, it looks like I finally managed to diagnose the root cause of the issue. I don't believe the TEA1611T chips and associated capacitors ever had anything to do with the issue. After taking the back off the TV and probing around I discovered a strange voltage present on pins 1-3 of connector P6. This had previously always been 0V when the TV had not been working but now measured 3-4V. As the F_STBY 15V supply was fine, and these should just be a switched version of this feed, it stood to reason that Q351 (the switching FET) must be at fault. It must have been failing to turn fully ON. I've not experienced this kind of intermittent failure before from a FET, in my experience they either work or they don't!

Like most parts inside this TV the original part was obsolete so I picked a suitable replacement (Texas Instruments CSD18533KCS, RS part number 827-4899) and replaced the part.

The TV turned ON first time and hasn't missed a beat since.

[sordids999]

Re: Panasonic Plasma TH-46PZ81B, 10 Blink SOS (Doesn't appear to be TEA1611T chips)

Hi guys
Just freezed mc201 with air and the tv turns on but can anyone point me to which capacitor is faulty and I believe it's a 1uf 50v cap ?

Thanks

[tvtimmy]

Re: Panasonic Plasma TH-46PZ81B, 10 Blink SOS (Doesn't appear to be TEA1611T chips)

Look on youtube for the norcal715 video of 2 or 10 blinks. I just remove the capacitors and leave them off.

[sordids999]

Re: Panasonic Plasma TH-46PZ81B, 10 Blink SOS (Doesn't appear to be TEA1611T chips)

Thanks I'll look

[vinceroger69]

Re: Panasonic Plasma TH-46PZ81B, 10 Blink SOS (Doesn't appear to be TEA1611T chips)

Hi guys
Just freezed mc201 with air and the tv turns on but can anyone point me to which capacitor is faulty and I believe it's a 1uf 50v cap ?

Thanks

you can just remove the cap i actually replaced both on both boards on my set and still using the tv as my main set
https://www.youtube.com/watch?v=LjpGKaBt8hg