Hi and welcome to JustAnswer,
Thank you for the question and your patience. Should you still need assistance for information purposes only...Initially, bear with us; re-confirm and post back with the complete model number of the Panasonic TV.
Appreciate the additional information.
Have you checked / replaced the HDMI cable?
...and re-checked / a review:
Have you tried another HDMI capable device to this TV? ...or the new DMR-BWT450 by HDMI to another TV?
Can you please try doing a RESET of the DMR-BWT450? ...pp. 70-71 of the Owner's Manual
Sorry to hear the lack of development.
Can we try a RESET of the even just the resolution/video format? Please p.88 of the Owner's Manual
Yes, a single HDMI cable from the DMR-BWT450's HDMI AV OUT to any of the TH-L32S10A HDMI port should allow video display from the Blu-ray to TV even if it were just the MENU.
Which then eliminated all other suspects except the DMR-BWT450.
Might a replacement DMR-BWT450 be more to your advantage ?
I realize that the above information may perhaps be not what was expected. Unfortunately, there is no quick-n-easy fix and neither is there a workaround thus the suggestion of a replacement; sorry for having to be the bearer of bad news.
And it would be beneficial to test run the replacement in the shop premises.