Tag: Interference

Net Killing RPi – SOLVED!!

With my troubleshooting exhausted, I turned to the Raspberry Pi forums in hope of some new ideas on how to fix it.

I was not disappointed. I quickly got answers pointing towards RF issues around the HDMI cable or grounding of the Pi/TV.

Ferrite clips along the HDMI and power cables failed, and initially grounding failed due to the fact I was using the whole 10 metres of cable I purchased to ground the Pi. Thinking this may be causing a lot of resistance for the low current used, I shortened it to around 50cm and…

Hooorah!

 

DIY solution to ground the RPi.
DIY solution to ground the RPi.

The Raspberry Pi and my internet working in close proximity and perfect harmony. The solution is to attach one end of a short wire to the HDMI port of the Pi, and the other end is attached to the ground pin of a standard socket plug.

This has been an expensive problem for me, 2 HDMI cables, a shielded RJ11 cable for the ADSL connection and a bunch of ferrite clips/rings when all I needed was a £2.39 piece of wire from Maplin. At least one benefit of this expense is the increased broadband speed, provided by the shielded RJ11 cable, taking my connection from 2.5Mbps to 3.2Mbps.

Its all working now, taking its place tucked behind the TV and providing me with a great media player solution, the abilility to control XBMC with my Bravia TV remote is an excellent feature.

My forum thread on the RPi forums can be found here.

Net killing RPi – Getting Somewhere…

In my last post I was a confussled mess, failing to get my head around how a network device (The Raspberry Pi) could cripple an exclusive function of my router.

I decided to troubleshoot the issue further, I set up a basic ping to help me pinpoint when the internet was going down

Ping results before Pi was switched on.
Ping results before Pi was switched on.

After performing some basic troubleshooting, it transpired that the fault was happening whenever the HDMI cable was connected to the Pi and my Television (Sony Bravia EX4-32).

Ping results after HDMI cable connected.
Ping results after HDMI cable connected.

Thinking it was a bad HDMI cable, I bought another, but to no avail. My next brainwave was that the Pi was emitting EMI (or RFI) which drove me to buy a 10 metre HDMI cable to get the Pi as far away from my router and other networking equipment, alas this didn’t work either.

Troubleshooting further, it turned out that the HDMI cable didn’t need to be properly connected, mealy touching the Pi on any metallic part will cause the internet to cease.

All it takes to knock me offline.
All it takes to knock me offline.

So in essence I am still no closer to solving my Pi/Internet mystery, if you can help me please comment!

All other HDMI works fine as I am now using the 10m HDMI cable as a screen extender on my laptop.

Bootnote:

In my previous post I signed off by stating that that the Pi and my internet were working in harmony. However it turned out that my modem had dialled back my downstream internet speed to 1.5Mbps instead of the usual 3Mbps, normally a result of the modem trying to obtain a more stable internet connection due to, lets say, interference on the line!