iMac G3 DV 400 won't power on after taking out the metal shielding around the DVD-drive and HDD

Elate

6502
I have an iMac G3 DV 400 I got for fairly cheap that won't turn on.

Originally the issue was a loose RAM stick, removing it finally got video on an external VGA screen, specifically the screen for when it can't find a boot drive (the Mac didn't include a HDD, I was aware of this) so it did turn on at one point.

At one point I attempted a PRAM reset, which seems to have reset the resolution / refresh rate to one not supported by my external screen. The CRT seems to not turn on so can't use that, that's a whole seperate issue I'll handle once I get it booting properly again.

I then read somewhere that the MacOS installation screen apparently forces it to a more normal resolution / refresh rate, so I tried that, but my DVD-ROM drive wouldn't work properly. Just made a loud mechanical noise, and wouldn't pull the DVD in. Eventually I just had to open it up and take it out manually, but after that it just won't boot.

PRAM battery is just fine. Brand new, 3.65v according to my multimeter. Basically what happens is the green power LED appears, boot chime plays, then around 7-10 seconds after the power button is pressed, it turns off. If I press the power button again, the power LED turns green, but no chime appears, and it never turns off. It kept being like this after I reinserted the metal shield and DVD drive, after taking out the IDE cable from the motherboard, just disconnecting the DVD-ROM drive, etc.

I've tried doing a PRAM reset several times, both through the button and the key combination (doesn't work, chime still only appears once). However there is one green LED on the motherboard, "DS11" with "+3.3v" written next to it. Right above the "HD/CD" pads where there seems to be space for a LED, but there isn't one. I'm getting a SATA to IDE adapter soon, so I'll be able to connect a SSD if that's related to the issue. I have yet to try testing for trickle voltage, I'll do that in a few hours from when I've posted this. The capacitors on the down-converter board seem just fine. I'll also try attaching a video of it right after I've tested for the trickle voltage. I would also prefer solutions that don't include opening it up to the PAV board as I don't have the tools to discharge the CRT, and I don't wanna risk breaking the inner bezel.
 

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I have been working on the same model iMac this week with similar issues. First, definitely check the RAM each time you do something inside it because it comes out fairly easy. There is a CUDA button I pressed just once while it was unplugged and the battery was removed. After replacing the same battery and doing this the HDD and DVD drive came to life and the iMac booted into Mac OS 9.1 CD.
The clock was wrong. Then I was able to boot the iMac from the HDD, Mac OS X Server 10.2.8.
The only thing is the screen on this works. I’m not sure if that’s necessary or not. Only an Apple branded keyboard seems to be able to do the keyboard commands at restart. All other usb keyboards here do not do the commands on restart.
Also, I’m not sure but it seems as though it requires the HDD to be present for it to turn on but I’m not exactly sure if this is accurate.
 
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