Hi,

I have a old Panasonic 42PHD-8 (768 resolution) plasma display, which always struggled with locking onto my HD621. When initially turned on, it would flash blue or blank screens. IIRC, after a good number of tries (off/on switching) it used to lock eventually and would be stable for a while. Having replaced it with a newer VT65 series Panasonic Plasma (sticking with plasma for now) I haven't had any issues.

One option for issue 1 might be to try a cheapo HDMI matrix switcher with two HDMI outputs (e.g. Portta HDMI 4x2 Matrix switch splitter from Amazon for £60) between the sources and the HD621. Obviously, if you're going to get a new TV soon, then I wouldn't spend a lot on a switcher/splitter but that might allow you to get things going again.

Just a thought,

Brian

Main: G65, MD600 Sooloos, MC200 Roon Core, MS600, 210, 218, UHD722, DSP5200SE, DSP5200HCSE, M6 & DSW.2
System 2: AC200 MS200, WiiM Pro+, M6.
Other: DSP5000 (96/24v1), DSP3300.