Chosen Solution
Panasonic TH-42PX75U does not see the horizontal top image. The bottom horizontal image is seen. It has sound. The SU-BOARD TXNSU1HNTU (TNPA4184) may be damaged. This has repair or it will be another area of the tv. With the TV on I loosen the tapes of the SU1; SU2; SU3; SU4 and horizontally in each of them when moving them out small lines of horizontal colors. Now clean all the connectors. Thank you and awaiting your response Actualización (20/03/18) I want to place an image that shows that half of the top horizontal screen of the TV screen is not displayed. That is the fault. Now check the continuity of the SHIPs of the SU-BOARD TXNSU1HNTU card (TNPA4184) from the SU1; SU2; SU3; SU4 and all are approx. in 8. It will be some component of the SC-BOARD stage.
@panasonic42 you are not telling us if you get any blink code from your power LED. Yes the SU would be the prime suspect since it is responsible for the scanning of the upper half. Post an image of what your board looks like and what your screen display. That way we can see what you see. Use this guide Adding images to an existing question for that.
