I'd have a good read of GeoffT's thread, he had good go at getting his tuner going, plenty of things to check.

http://empeg.comms.net/php/showflat.php?Cat=&Board=empeg_general&Number=141468&page=2&view=collapsed&sb=5&o=0&fpart=

But first,

chip orientation
signal/AGC wires
ariel grounding