Need help troubleshooting one of my lights

[Punjab]

Yesterday one of my 250w double-ended lights went out. I have icecap electronic ballasts and icecap 250w-400w pendants.
I immediately assumed the bulb simply burnt out and bought a pair of new bulbs today. Put them in and still nothing from the same fixture. I switched the ballasts and the ballast on the non-working light fired the other pendant so both ballasts seem to be working fine.
I also switched out the bulbs thinking maybe I just received a bad bulb and installed it on that side but I can't get any bulb to work in that pendant.
Is there anything in the pendant itself that could have somehow malfunctioned and is preventing the bulb from firing? I looked around the pendant a little but couldn't see anything obvious.

If you have any suggestions please help and thanks!

 

[Craigar]

Check the wires to see if one came off or melted. Also check your contacts for corosion and build up.

 

[Cake_Boss]

^ Yup.

Check your bases, they might be bad

 

[Punjab]

Okay, I took the fixture apart and sure enough there is a point of contact burnt out. I don't really know what this piece is though.
Does anyone know where I can find a new one of these little white squares?

Thanks in advance!

 

[Punjab]

I fixed if after all. I just replaced that ceramic square with some wire connectors and it's back up and running.

Thanks for the help!

 

[Boogie]

Just make sure that plastic block is just a junction and not some sort of resistor (I know nothing about electricity, just want you to make sure)