Panasonic tx55cr730b no picture

[Rob0904]

Hi. I have a Panasonic tx55cr730b which doesn't display a picture (no start up logo, no menus). It does show a green power light, goes into and out of standby fine. When the green light is on I can hear clicking from the av board. Would thus suggest that the av boards is faulty or a power board issue.

Any help would he great.

Rob

[Andrew F. Ali]

Re: Panasonic tx55cr730b no picture

Do you have all the signals/voltages required by the PSU from the Main Bd.? You seem to have the signal/voltage required by the Main Bd. from the PSU.

[Rob0904]

Re: Panasonic tx55cr730b no picture

To be honest I've just had a quick mess about in the back, no major investigation. If I pull any of the cables out of the av board the tv wont turn on at all. So that's as far as ive gotten.

Clicky av board and normal reactions from the remote.

I will have to get the multimeter out. So hoping someone may of had the same symptoms as mine and kind of say yeah 99% this board.

Rob

[budm]

Re: Panasonic tx55cr730b no picture

We need more details such as if you getting backlights or not, or if the backlights only come on for seconds only, without light source then you will not be able to easily see anything on the screen.

[Rob0904]

Re: Panasonic tx55cr730b no picture

Yeah sorry forgot to say back lights come on and stay on. It looks like the back lights change if I press source or tv buttons on remote. It's only slight but something is happening.

Rob

[Rob0904]

Re: Panasonic tx55cr730b no picture

Hi all, changed the av/main board but still getting a no picture and a clicking sound from the new board.

Still turns on as it should no flashing red light.

There is two power boards in this tv, if I pull any cable out of the av board the tv doesn't power on.

Any help would be great.

[nomoresonys]

Re: Panasonic tx55cr730b no picture

Start with the basics: Test connector from mainboard to powerboard on powerboard side with all boards hooked up, test with tv plugged in but off then hit power, report both conditions here, give pin number, pin description/name and condition both off and when you hit power on.

[budm]

Re: Panasonic tx55cr730b no picture

Lets see the pictures of the whole backside of the TV showing all the boards so we can see what we are dealing with.

[Rob0904]

Re: Panasonic tx55cr730b no picture

Thanks for the replies. I'm at work at the minute but I've had a mess earlier.

I can get sound but no picture even doing the the flash light trick. I pulled each ribbon from the tcon board and made no difference.

Does this point to the tcon board?

I will get pictures up tomorrow.

Rob

[budm]

Re: Panasonic tx55cr730b no picture

Need to at least find out if the T-CON is getting 12VDC for it to run or not.

[nomoresonys]

Re: Panasonic tx55cr730b no picture

Do a quick check of the fuse on tcon board should be labeled Fxx, see if you have about 12 volts on each side of fuse, red probe on one side then the other, black probe on chassis ground.

[Rob0904]

Re: Panasonic tx55cr730b no picture

Thank you, I will get on it as soon as I can might be the weekend now tho....

Rob

[Rob0904]

Re: Panasonic tx55cr730b no picture

Hi, my brother managed to get a new tcon board before I have got chance to have a look at the tv. It now has the colour test screen cycling red, green, blue ect...

Any idea how to get out of it?

Thanks

[budm]

Re: Panasonic tx55cr730b no picture

Did he match the P/N for the PCB assembly as printed on the sticker NOT the PCB P/N as printed on the board?

[nomoresonys]

Re: Panasonic tx55cr730b no picture

May have gotten a mismatch as suggested, did you try unplug tv for a few minutes? If same when you plug it back in, try turning off and on with the buttons on the tv.

[nomoresonys]

Re: Panasonic tx55cr730b no picture

Press and hold the TV's power on button for 30 seconds and then release the button. Plug in the TV power cord back into the wall outlet, then try it.

[nomoresonys]

Re: Panasonic tx55cr730b no picture

Hold down the power button on the tv not the remote, while the tv is still unplugged for 60 seconds after 60 seconds continue to hold down the power button and plug it in.

[Rob0904]

Re: Panasonic tx55cr730b no picture

Hi all, just an update none of the above things worked. As we had changed the av board, I got my brother to put the original one back in and hey presto the tv is alive!!

I can send the replacement av board back so not a bad result.

Thank you for all your help and time.

Rob

[nomoresonys]

Re: Panasonic tx55cr730b no picture

Good to hear, must have been a dirty/loose connection or ground or maybe the tv somehow got a proper reset with the replacement board.

[Rob0904]

Re: Panasonic tx55cr730b no picture

Original av board and new tcon sorted it out.... time to send the spare av board back for a refund 👍👍

Thank you again for the help.

Until next time 🤣🤣