G3 and G4 logic board differences?


Anyone know of any differences b/w the Blue & White G3 logic board and the PCI G4 logic board?

I recently had to purchase a refurbished logic board for my Blue & White Power Mac G3. I contacted Allmac (http://www.allmac.com/) and requested an identical logic board be sent. I received instead a Power Mac PCI G4 logic board. Obvious differences: NO ADB port though the electrical contacts are there, and the sound quality in the music just doesn't seem to be there. The sound quality issue is the one I'm very disappointed about. Is this G4 logic board "cheapened" in any way from the G3 logic board regarding sound quality that anyone knows about?

This unexpected purchase is not related to my recent attempt to overclock my 400MHz G3 processor. The 400 MHz G3 processor still worked even though it was replaced with an IBM 500MHz G3. The university I attend has a PC repair depertment that diagnoses for free PC's and Mac's. They determined that all my cards and memory were fine but could not determine if teh processor was dead without another Mac present. It's up to the user to replace any components and they do provide really good parts warehouses.

G4 logic board: $400.00 with trade-in.
IBM 500MHz G3 (Copper): $300.00.

The reason I had to purchase a refurbished logic board was because I took my Mac to a friends house, installed some new memory and returned home. I connected the keyboard to the USB ports without the computer being plugged in (AND MORE IMPORTANTLY, GROUNDED) fried the USB portion of the logic board from static discharge. Always have your computer grounded when connecting perpherals to any ports.


My new FrankenMac:
Blue & White G3 (case) with G4 logic board, 500MHz G3, 768MB RAM, 12GB UltraATA, 18GB Ultra SCSI
I know that the early low end G4s used the same technology for their logic boards as the original Blue & White G3s, so I can see there not being a problem substituting one version for the other, but they all have different part numbers from Apple.

B&W G3 Rev 1 Logic Board: 661-2104
B&W G3 Rev 2 Logic Board: 661-2194
G4 (PCI) Logic Board: 661-2253

The most notable difference being the loss of the ADB port in the G4 version. Of course this should make upgrading to a G4 easier (not that it wasn't before).
You are correct. They are those logic boards. The Power Mac G4 codenamed Yikes running at 350MHz and 400Mhz were just the next revision casings with a B/W logic board hosting a ZIF PowerPC 7400 (G4) chip. No difference what so ever.
Just wanted to add the next after that were the codename Sawtooth (AGP), after that Digital Audio (133MHz bus), and now Quicksilver (Quicksilver).