I own a Panasonic plasma TH-50PX80U and it is 1 year and 4 months old. I have basic cable and when I turn the tv on the picture goes black a second later and the chanel that it is stuck on blinks on and off. I am able to play dvds and the cable line is good?

Everything is fixable, but it is a 17 year old set, with old technology. In these days of Internet connectible, Smart televisions with 4K picture quality, you would notice a big difference. I would say you have had your moneys worth out of it. Its up to you, service centre, or a new one.

Panasonic TH-PX77U review - CNET.com

www.cnet.com > reviews > panasonic-viera-th-50px77u...

Apr 12, 2007 - Panasonic's internal menu system is intuitive enough, although we disliked the ease with which you can inadvertently erase your picture settings. With a native resolution of 1,366x768, the Panasonic TH-50PX77U matches the resolution of just about every available 50-inch plasma today.

https://www.fixya.com/support/r29790007-repairing_own_television

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Are the speakers' cables connected correctly? (p. 37) Is "Sound Mute" active? (p. 13) Is the volume set to the minimum? Is "Speaker output" set to "Off"? (p. 22) Change "SAP" settings. (p. 16) Check "HDMI 1 in", "HDMI 2 in" or "HDMI 3 in" settings. (p. 22)
Hope this helps, page# refer to your manual.

it could be either the SD or SU boards going. check the cable connections and make sure the ribbon cables are seated properly.

I have the same problem. Factory reset did not help (hold Vol-minus on set and menu on remote five seconds, then unplug). Can there be something in service mode that would help?

i think there is a moisture on your internel LVDS cables

Suplly capacitors faulty need to be replaced

Same issue with - Panasonic TH-50PX70A , power UP with red standby, then power ON by remote - only Gives GREEN led blinking 35-40 times, followed by solid green led with no no picture no sound.
>> Solution; unplug Plasma from AC 10-15min, then plug in & power on to Red standby led,, At this point - Power ON tv while holding down both -Volume Down and F (function Select) buttons (front panel door) at the same time turns picture ON,all ok.

From your description it sounds like your power supply if faulty. You can get parts for this TV at www.interliquidparts.com

What surround sound system can I buy to go with my panasonic viera th-50px80u plasma tv. One where I can here sound from cable and bluray

check and reseat all the connections on your T-con board which is located in the midle top of your unit there will be a cable from the mainboard and 1 or 2 from the top to the panel carful those connectors are cheap clean with rubbing alcohol