Power Mac G3 B&W Rev.B - no chime, no video - Please help!

[xkola12345x]

I've recently acquired a B&W Rev.B Power Mac G3. I used to have one back in the day, and wanted to relive some memories. I know these machines can sometimes behave in wired ways, but after going through many troubleshooting procedures I'm honestly out of ideas.

I bought it, but due to covid restrictions seller shipped it to me. Before buying I got the video of the system running Mac OS X 10.4.11 Tiger, but as agreed with the seller, the system came without HDD for privacy reasons.
Tech Specs:
400Mhz CPU overclocked to 450Mhz
1GB RAM
ATI Radeon 7000
DVD-ROM Drive
USB 2.0 PCI Card (removed for troubleshooting)

When I got the computer I tried booting it of the original restore CD (it is Mac OS 8.6 restore CD for Power Mac G3) for the system that I had lying around, but without any luck. Holding C as written on the CD doesn't make a difference.

Troubleshooting already done:
I basically followed this thread, but without success.
From service manual, that I attach I did the following procedures:
1 Check video cable/card connections.
2 Check jumper block configuration at J25. (Tried underclocking to 400Mhz and 350Mhz with no luck, though old hard drive jumpers I had lying around seemed a bit too wide).
3 Reset Cuda chip.
4 Reset logic board. (I'm not 100% sure I performed it correctly)
5 Reseat the video card.
6 Reseat the SDRAM DIMMs.
7 Reseat processor module.
8 Remove all SDRAM DIMMs and try replacing them one at a time to test. (I unfortunately do not have any spare working PC100/PC133 DIMMs)
9 Replace monitor cable

I also removed the PRAM battery and tried repeating this procedure. I know that B&W should boot without it, and will try replacing it later.

From Logic Board LEDs it looks like DS7 & DS8 are in sync, and DS9 lights up during boot up.
I can start the computer using Apple USB Keyboard (M2452 - that one with power button), but there is no power coming to it and Command+Option+P+R yields nothing. DS4 & DS5 don't light up. From my tests, if I plug in keyboard into USB port of the PCI card, its caps lock light lights up for a split second, so it seems that the PCI bus is getting power. I unfortunately don't have an ADB keyboard.

As for DVD drive - I can only open it when its IDE cable is disconnected from the logic board.

Tomorrow I will try to repeat the whole procedure but, apart from it, I'm out of ideas and ask you for help.

Edit:
Link to the manual

 

[xkola12345x]

Ok, it's me again. During the weekend I was able to do some further testing and here is what I found.

I was able to test the RAM on my friend's iMac G3 and it looks like it is working. iMac was able to use it without any problems, but when I tried to boot the B&W with only one stick of RAM (I tired with each one), there was no effect, even after CUDA and Logic board resets, but I heard read somewhere, that G3 Power Macs sometimes need a couple of those to get going.

It also seems that the CPU is working, as the heatsink is getting hot when the machine is running.

After all troubleshooting I did, I'm out ideas. Is there anything else I can do to fix the machine, or is it some kind of logic board problem and there is no hope of getting the computer working?

 

[Dronecatcher]

I can't offer any help only sympathy - the one Powermac G3 I had was so delicate I feared breathing too hard near it...
It was fussy about everything - RAM, hard drives, optical drives, graphics cards, firewire....I was glad to see it go!