Only Cowbell, Cymbal, and hihats working....

Hoped it would be the 4011 IC in the accent problem that a few other people were having, but I've just replaced that, so unless I'm very unlucky then I don't think it's that..

I've tried in expander mode, to eliminate whether the sequencer isn't triggering it properly but I have the same result.

What should I try next?

Not sure what you tried already but you can check to see if you are getting triggers sent to the instruments. For example, for BD check trigger signal at the base of Q40 and also Q39 using a scope or a soundcard scope.

If you are getting trigs, then the first step is check solder joints and component values.

Oh also, hihats only sound if accent is on, and the accent amount affects how loud they are...

Sooo... At the base of Q40 (The base is the pin on the left, as we are looking at the flat side, yes?) I get a pulse which corresponds to the accent, but at the base of Q39 I get nothing, although all steps are lit..

Soooo I'm, getting triggers from pin 1 of IC5 as expected for the kick drum, bit I'm testing continuity from there to R155 which there should be, I think, but there is none...

EDIT: I was thinking that 'TRIG' on the schematic was trigger in, where in fact it is BD which is the trigger in..

Soo... Base on Q39 shows a pulse on the scope as I would expect from the active steps, but I can't find anything similar on Q40, the base of that seems to be the accent trigger, which is consistent with the parts that are working..

What to try next?

It's weird that it is the part which are all controlled by IC5 that are not working, but I used a wire to send the BD trig to the cymbal and the cymbal triggered on the active BD steps, as expected, so it seems that IC5 is working as it should...

So I checked for triggers at U12, and there's nothing there.. I did however manage to steal a trigger from the hihat 4558 chip and heard the kick

So, I have no pulses on the collectors of any of the 2nd transistors in the trigger circuit (equivalent of Q40 in the bass drum part).>

Buuut, I've just had a bit of a break through - If I join the collector of Q40, to the collector of Q8, then everything is triggered as it should be... Weird...

Obviously I'd rather fix it properly than just connect a wire across there, but maybe just for tonight, and seeing as I've recently got a x0xb0x...

Ah, not quite - if I make that join then instruments are triggered as long as there is also a hihat trigger on that step...

(And the kick is triggered with every hi hat, too, as you would expect...)

Okay, so I got another 4011 (I soldered in a socket last time) and still have the same issue, so I think it's fair to say that it isn't that.

There must be some issue with the accent part somewhere, but I don't understand how feeding the trigger from the hihats to the bass drum also makes all of the other parts work. Or could it be either of the two transistors in the bass drum part?

Also, as I said previously, unless the accent is on a step, nothing is triggered, not sure if this is the same or a separate issue.

Any ideas? I'm keen to get it up and running 100% before the year is out