TL;DR version of my problem - A500 with Indivision ECS v3 (no joystick attached in CN2) constantly moves up. Works with standard Denise.
Any idea what could be so close to failure that an original Denise ignores it, but the ECS triggers?
At first I didn't even think about swapping back to the original Denise, since everything on the forums pointed me towards the multiplexer at U15.
Multimeter and logic probe (I'm no expert) indicated that it was working, but I socketed U15 anyway. It tested OK with a TL866-II programmer, but I ordered
replacements from China anyway. They also tested OK, and work with the standard Denise. The ECS v3 is flashed with the latest firmware (20201120) and I have the latest tools (v2.7).
The A500 is usually maxed out (Gotek, ACA500+, ACA1232, XSURF500) with a CA-PSU and everything is stable. Now I'm testing with only Gotek and Indivision ECS v3, not even extra RAM.
I should test the Indivision in one of my spare A500s, but this one's my favorite and I would like it to keep working.