Originally posted by: mindless1
Originally posted by: MrDudeManThere may be multiple paths in a case, but I think he meant simply connecting a single, alternate ground to the motherboard in some way. If that were the case, then it could be a significant issue. I'm not familiar with the grouding inside of a computer case, but I was under the impression that most of the grounding was done through the ATX connector, making a "single" ground connection.
Alternate paths to the motherboard in a case include the standoffs the board is mounted on, card brackets that are ground and touching or screwed to the case (ground), drive/other peripherals with grounded metal cases screwed to the system case.
Alternate paths regardless of case, may include video card with power connector, drives, sound cards with cables connected, video or capture/tuner cards with cables connected, other cards.
It would be a very unusual system to not have several ground loops. Sometimes the loops DO cause issues, like when it's not a digital signal but rather analog on integrated sound you may get noise on the output depending on system load. Sensitive amps->speakers are more likely to reveal that noise.
Yes the only "required" ground is through the board (or other parts' connector) pins/leads, but if there were a single alternate ground to the board, it should still work fine.
What types of problems could a grounded loop cause in a PC? If possible non shorted results could happen say a cheep Board and say a combination of plastic and metal standoffs or some such thing? Could there be a noticeable affect on system stability?