Insulation of motherboard screws?

[ExplodingBoy]

I have a question. I recently rebuilt a system and neglected to use the little cardboard washer things on the motherboard mounts. This particular system has a ground-loop hum problem when hooked up to my TV. Could the hum be caused in part by all the ground points on the mobo?

Any chance of a better PS preventing the hum?

 

[amdskip]

I never use these washers. A power supply should not have much hum, which one is it?

 

[lenjack]

There is no need to insulate the mb mounting screws. If you're using a new mb or case, be sure the are no standoffs anywhere but at the mounting holes

 

[ExplodingBoy]

Ok so it's not the insulators; no standoffs on this mobo/case ... just bolted directly to the case.

The PS is a no name 300W that was advertised as being Athlon ready. Bought from PC Alliance. Prolly its a Linkworld although I'm not sure. Wouldn't be surprised if it's a bad PS.

 

[jaeger66]

Ground loops are almost always due to cable TV lines that are not grounded or grounded poorly outside the house. Get 2 300-75 Ohm matching transformers(Radioshack part numbers 15-1140 and 15-1253), hook them together, and insert them into the cable TV line before any components. If the hum stops, call the cable company. If it doesn't, instert them between components and if it stops after your VCR, cable box, or soemthing else then that component should be replaced. If none of that works or if you don't even have cable, it's likely the PSU.