I need help changed power supply board and ss board and still no picture it is a model TC-42PX14 panasonic the red light still blinks seven times. At wit s end isn't much, can you help me.t

Page 50 and 53 of the Service Manual

https://www.manualslib.com/manual/2311596/Panasonic-Tc-P55vt60.html?term=3+blinks&selected=3&page=50#manual

3 Blinks
Yes
A1 and disconnect the
Blinking
Is the power LED
3 times
off or is it blinking 3
times continuously
at a fast pace ?
Replace the
K board
Applies to Models
TC-P55VT60
TC-P60VT60
List of boards likely to cause this
symptom.
No specific order
P, SS SC, A, K, Bluetooth module,
Cs, Panel


..

These blinks [flashes] are fault indication (Error Codes). From the number of blinks occur at one time switch ON, you can get an idea about the faulty circuit section inside it. This will make repair easy. These are called blinking codes. Make sure about the exact number of blinking of the standby/power LED, by switching On & OFF the set, for at least two times. Count it carefully. If you wish to get some details, check the site linked here. It has details about blinking codes, and fault locating procedure, to many popular brand TVs and other devices. http://electronicshelponline.blogspot.com/

Panasonic 46 TC P46G10 TNPA4783AC Main Board Unit

With 10 blinks it could be any of the following boards, the blinks tell you that is is a power problem

A-Board TXN/A1LPUUS
SC-Board TXNSC1LPUU
SS-Board TXNSS1LPUU
P-Board ETX2MM806ASH

use this chart to help isolate the problem

check the connections. if the ribbon cables are seated correctly, this will cause picture issues.

You may want to shop for that board or at least consider removal of the HDMI socket in question---tested for shorts there I presume?

thought I would post this here for everyone.

1 blink STV 5v sense DG Board

2 blinks 15v SOS D Board

3 blinks 3.3v SOS D Board

4 blinks Power SOS P Board

5 blinks 5v SOS D Board

6 blinks Driver SOS 1 SU / SD / SC Boards
(SC energy recovery circuit)

7 blinks Driver SOS 2 SU / SD / SS Boards
(SC floating voltage area)

8 blinks Driver SOS 3 SS Board
(SS energy recovery circuit)

9 blinks Panel Config. SOS

10 blinks Sub 5v SOS / Main 3v SOS DG Board
DTV 9v SOS / Tuner Power SOS

11 blinks Fan SOS PB Board

12 blinks Sound SOS H Board

13 blinks Communication error DG Board
with IC8001 (Pesks Lite 2)