Gues what... Leaking Caps...
All capacitors where leaking but I could clean the board using spiritus alcohol and now it boots up nicely - I even get the screen jumping away
But strange - the IIsi ROM did not boot the patched System 8.1 - there was NO Simasi effect as reported but after two seconds I got a blackMac with an Error Code (I did no remember the code...).
After re-adding the IIfx ROM SIMM I am back to Simasi for 3 seconds but after that MacOS 8.1 boots quite fast.
I will add the IIsi ROM back to see the Error Code again - maybe I get some more infos why the IIsi ROM did not work. Get back to you soon.
All capacitors where leaking but I could clean the board using spiritus alcohol and now it boots up nicely - I even get the screen jumping away
But strange - the IIsi ROM did not boot the patched System 8.1 - there was NO Simasi effect as reported but after two seconds I got a blackMac with an Error Code (I did no remember the code...).
After re-adding the IIfx ROM SIMM I am back to Simasi for 3 seconds but after that MacOS 8.1 boots quite fast.
I will add the IIsi ROM back to see the Error Code again - maybe I get some more infos why the IIsi ROM did not work. Get back to you soon.