TV Forums

Free Games Games Forums Music Forums TV Forums

  Main Index FORUM
HOME
Search Posts SEARCH
POSTS
Who's Online WHO'S
ONLINE
Log in LOG
IN
Rules & FAQ RULES
F.A.Q.

Crumbtrail TV Forums: TV Equipment: TV Repair Forum:
Panasonic TH-42PZ85U 11 blinks

 

 


ROB56
New User


Sep 1, 2016, 4:08 AM

Post #1 of 8 (871 views)
Shortcut
Panasonic TH-42PZ85U 11 blinks Can't Post

I guess it was inevitable that this would happen. I bought this TV new in 2008, and for most of those eight years it has ran 24/7 and never given me a minutes trouble, until three days ago when I fell asleep on the sofa watching TV and when I woke up, the TV was off and the red power indicator LED was blinking.

I pushed the power button on the set, it came on for about 3 seconds, then shut off, the LED blinks 11 times, then pauses, then 11 more blinks, pause 11 more..etc.

I got on the Internet, discovered the "blink codes", and according to that info (SOS PB Board, Fan Control), so....being into hobby electronics, I took the back off the set and found the cooling fans to be absolutely caked in dust, but very little dust, if any at all, on the circuit boards. Using my little portable compressor, I blew all of the dust off the fans, and very gently and from a distance, off the circuit boards.

I thought that might have fixed it, but it's still doing the same thing. Push the button...comes on for 2 or 3 seconds....shuts off, then the 11 blinks.

I then removed the PB board, and visually inspected it, and from a visual standpoint, it appears to be perfect. The two 470uF electrolytic caps and the 100uH inductor all look fine. On the back of the board there are a bunch of surface mount resistors, capacitors and diodes, and a 4 pin + lead component. Everything looks good, no burnt traces or anything.

I haven't tested the fans yet. I have a benchtop power supply that I can use, but the TV is in the other room. I'll have to make some jumper leads that are long to reach in there. I have more than enough 26awg wire to do the job.

Now to my questions....
1.) Is this 11 blink code usually the PB board itself or just a faulty fan?
2.) If the PB Board DOES go bad, what is the culprit? Is it the little surface mount IC on the back of the board? The markings are 1CN38M, but it must be long obsolete, a google search turned up nothing. I couldn't find a datasheet. That device, whatever it is, is the only controller on the board, everything else is just passive.
3.) Maybe I'm over-thinking it. Do I just have a bad fan?

=========================================
FIX IT!!! Don't throw it out. We have enough junk as it is.



jts1957
Veteran


Sep 1, 2016, 10:48 AM

Post #2 of 8 (856 views)
Shortcut
Re: [ROB56] Panasonic TH-42PZ85U 11 blinks [In reply to] Can't Post

http://imgur.com/a/hx5bG
http://imgur.com/a/lbEzw


-------------------------
Location: Far, Far Away

(This post was edited by jts1957 on Sep 1, 2016, 10:50 AM)


ROB56
New User


Sep 2, 2016, 9:44 PM

Post #3 of 8 (837 views)
Shortcut
Re: [jts1957] Panasonic TH-42PZ85U 11 blinks [In reply to] Can't Post

thanks jts1957, that's exactly what i needed. you must have pulled those pics from a repair manual. Wink

=========================================
FIX IT!!! Don't throw it out. We have enough junk as it is.


jts1957
Veteran


Sep 2, 2016, 10:38 PM

Post #4 of 8 (835 views)
Shortcut
Re: [ROB56] Panasonic TH-42PZ85U 11 blinks [In reply to] Can't Post

Close: http://imgur.com/a/qT7vp


-------------------------
Location: Far, Far Away


ROB56
New User


Sep 2, 2016, 10:59 PM

Post #5 of 8 (834 views)
Shortcut
Re: [jts1957] Panasonic TH-42PZ85U 11 blinks [In reply to] Can't Post

Well the verdict is in. Apparently I have a bad fan. The set stayed on after I put the jumper in on the 2nd fan I was testing, then plugged the tv in and turned it on, and walla...it stayed on. The part# for those fans is L6FAYYYH0050. I've found some on ebay, unless someone knows a better place to buy the.

I was wondering if it would hurt anything to leave that jumper in (and the rear panel off ) and use the set until the fan gets here?

=========================================
FIX IT!!! Don't throw it out. We have enough junk as it is.


ROB56
New User


Sep 2, 2016, 11:05 PM

Post #6 of 8 (833 views)
Shortcut
Re: [jts1957] Panasonic TH-42PZ85U 11 blinks [In reply to] Can't Post


Quote
http://imgur.com/a/qT7vp


I knew it, you sly dog....Cool

=========================================
FIX IT!!! Don't throw it out. We have enough junk as it is.


ROB56
New User


Sep 3, 2016, 12:21 AM

Post #7 of 8 (831 views)
Shortcut
Re: [jts1957] Panasonic TH-42PZ85U 11 blinks [In reply to] Can't Post

I was just looking at that diagram in the first pic you posted. When I was checking my pb board for friedness, I figured that lone IC looked like a buck converter, as it had all the ingredients mixed in with it, the two 470uF caps, the 100uH inductor and the schottky diode, the perfect mix for a low power dc-dc voltage regulator.

=========================================
FIX IT!!! Don't throw it out. We have enough junk as it is.


T350T
New User

May 16, 2019, 6:24 AM

Post #8 of 8 (79 views)
Shortcut
Re: [jts1957] Panasonic TH-42PZ85U 11 blinks [In reply to] Can't Post

Many thanks for your post it helped me find the problem with my PB board and cost me 9.50 for a new replacement, so joined the forum just to thank you for the time you took to help others and therefore thought i would drop a note to thank you. All the best Tom

 
 
 


Search for (options) - Page loaded in: 0.25 s on (CGI/1.1)