My friend cannot watch tv and get online at the same time?

[X-Nemesis]

Here's how they have things set up atm:

There's a splitter (rca home theatre 5-1000mhz) between the tv and the Mac
Whenever both cables are hooked up, the internet always cuts out
The wireless on the ps3 disconnects when the internet upstairs is connected

What would any of you recommend for troubleshooting this issue?

 

[tha_vice]

Bad splitter. Call the cable company 🙁 or buy an new one, but you also need to ensure the signal strength is good enough to even be split.