I've got an Amiga 1000 (rev 6) that my family has had since we purchased it new. During that time it's always been kept indoors and been well cared for (especially not stored in a garage or anything like that).

However, upon powering it on recently (for the first time in who knows how long) I noticed it no longer works properly. It starts to do the normal bootup sequence, plays the usual startup tones, and then stops at the blank white screen you get right before it would normally show the kickstart insertion prompt/screen. Neither the internal nor any external floppy drives work (although the external floppy drives I've tried I know work as I've tested them on a second Amiga 1000 I have) -- the familiar drive clicking is not there for it to detect disks being inserted/removed). Also the internal floppy drive's LED stays solid on from the time I turn the Amiga on.

The Amiga itself is completely vanilla. The only expansion we ever used with it was a 1MB fast RAM board that was connected to the expansion slot on the side (which I removed before powering it on for the first time).

Things I've tried thus far:

• Reseated all of the socketed chips. None of them have any kind of corrosion or physical problems.
• Swapped the two CIAs around.
• Using a Classic 520 on the expansion slot to replace CPU and kickstart.
  • Enabling only the kickstart ROM functionality of the 520 results in the Amiga showing the appropriate kickstart screen (kickstart 3.1.4 in this case). I then tried holding the left+right mouse button to get to the Amiga boot config menu to have it boot off of DF1. If I then click "boot without startup sequence" sometimes the LED on the external drive will light up and I hear the motor spinning for several seconds, but then the LED goes off and the motor stops and it goes to the kickstart screen.
• Enabling all features of the Classic 520, everything besides floppy drive access seems to work. I can boot into Workbench 3.1.4 and use it just fine.
• Running the memory, CIA timer, and audio tests from Amiga Test Kit (1.2.0). All of them pass. Trying the floppy drive tests for either internal or external floppy drives results in "no track 0" errors. At least with a known working external floppy drive, when I tell it to turn the motor on, I see the external LED come on and hear the motor spinning, but that's about all it does.

Based on my research, it seems only 3 chips are involved with floppy drive handling on the 1000: Paula and the two CIAs. Since audio is working, I'm inclined to believe that Paula is probably working fine, unless it's partially bad (is that even a possible/common failure mode on Amigas?).

Is there any way to narrow down further where the problem lies exactly? Perhaps some additional software I'm unaware of? I know the DiagROM project seems to also have IRQ/DMA tests and has a (minimal) version for the 1000, but unfortunately I don't have an EPROM programmer nor any EPROMs.