Warning about cheap leads

[IriDium]

The other day I used my USB lead from my Rpi to charge my phone at work. Unfortunately I left it at work.

I knew I had a spare lead, routed in my lead drawer and found a cheap (Ebay job) USB to micro USB lead. That will do I thought. I checked the voltage 5.15v - Ok and plugged in the Rpi.

The PSU is 5v 3.8amp and powers the RPi and the hub. The RPi connection has seen 756ma so will draw what it needs.

It worked....... almost. The ethernet sometimes worked, and then the screen started going black and then back to XBMC. The KB and mouse failed to function.

Puzzled, I plugged in a spare 1amp PSU and all worked fine.

I stripped the lead, and at 10cm it was only supplying 465ma, at it's full length - 1m - it was only drawing 265ma.

No wonder I was having problems, I'm surprised the RPi even booted.

Morel of story: Don't buy cheap, and check more than just the PSU if your RPi displays strange behaviour.