e74 means a problem with the av cable, try a friends and just try to see if it works with the standard rca cable - also try using a genuine M$ cable
gigabite
I tryed all of them before I post here my first message.Maybe something like a fuse blowned when I plugged AV cable.So I will try remove&change all transistors on the AV-Output.
I have pictures about it if you need I can post it in here.
Thank you.