Welcome to the Army.
Grey is the normal shade of the raster screen when video first starts, or when the desktop is present, although you can change the pattern of the desktop. A black screen indicates no video activity, or that the brightness control is at minimum, or that Sad Mac is hanging about (and you should see him at centre-screen).
Happy Mac is an indicator that the system has found valid boot blocks pointing to the System Folder. That this is where the startup process stalls indicates that the System Folder is not valid. It could be corrupt, or not blest (blessed), or even not there at all, despite what Happy Mac has been told. How did you come by the startup disk? You may need a new one, or a rewrite of the present one.
Sitting in a garage for GKHL may or may not have done mischief. How wet, cold, dusty or long was the storage is the touchstone. Most probably the PRAM battery may have run down, but that is not a critical disability in a floppy-driven Plus unless the dead battery spilt its intestines into the Mac. If you have doubts about the Mac's internals, opening, inspecting, cleaning and tarting-up may be the way to go. There is ample info. in this Forum about the process, and also debunking the death-and-damnation hysteria associated (largely because of Apple's lawyers) with opening a Compact AIO. If you don't need to work on the CRT, don't touch it and it will not bite you in return. Remember the thistle, and Nemo me impune lacessit.
The screen garbage may very well be a function of the Vampire Video that the monochrome 1-bit Macs use. They use system RAM as VRAM, and DRAM at that, so whatever was last in RAM and is still passing from RAM may be visible on-screen between its normal active states. Screen patterns can also be diagnostic of system faults, if they persist while the Mac is active.
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Grey is the normal shade of the raster screen when video first starts, or when the desktop is present, although you can change the pattern of the desktop. A black screen indicates no video activity, or that the brightness control is at minimum, or that Sad Mac is hanging about (and you should see him at centre-screen).
Happy Mac is an indicator that the system has found valid boot blocks pointing to the System Folder. That this is where the startup process stalls indicates that the System Folder is not valid. It could be corrupt, or not blest (blessed), or even not there at all, despite what Happy Mac has been told. How did you come by the startup disk? You may need a new one, or a rewrite of the present one.
Sitting in a garage for GKHL may or may not have done mischief. How wet, cold, dusty or long was the storage is the touchstone. Most probably the PRAM battery may have run down, but that is not a critical disability in a floppy-driven Plus unless the dead battery spilt its intestines into the Mac. If you have doubts about the Mac's internals, opening, inspecting, cleaning and tarting-up may be the way to go. There is ample info. in this Forum about the process, and also debunking the death-and-damnation hysteria associated (largely because of Apple's lawyers) with opening a Compact AIO. If you don't need to work on the CRT, don't touch it and it will not bite you in return. Remember the thistle, and Nemo me impune lacessit.
The screen garbage may very well be a function of the Vampire Video that the monochrome 1-bit Macs use. They use system RAM as VRAM, and DRAM at that, so whatever was last in RAM and is still passing from RAM may be visible on-screen between its normal active states. Screen patterns can also be diagnostic of system faults, if they persist while the Mac is active.
de