Analogue-sequencer

> Perhaps it worked the first time because I hadnt messed with it for a 
> few hours and some cap had discharged or something??  

It sounds like there is something causing it to only boot up successfully
for a short time.
At a guess, I'd check the polarity of the electrolytic cap on the CPU reset
pin - C3.
That might cause the CPU to go into reset if it is the wrong way round.
After that, check all component orientations and solder joints.

Cheers,
Colin f