finally got it. it was Q14

Still not getting anywhere with this thing

sorry, across the led it's only 1.9v to ground i was reading 9v . rotating the knob only changes the voltage by about a half a volt

strange thing i noticed, trim pot 1 changes the speed

the ribbon cable checks out ok, and i'm getting 9v at nsl32

OK so I'm back to working on this beast. seem to have the voltage prob worked out, replaced all ic's .still a few problems i need to track down ,the output is very low and distorted

any ideas on why the speed wont work? replaced the pot,checked connections, no change

ok.... finally! u3 wast the problem butttttt. i have no speed controll

scratch that ---- something on CH1 just went bad and blew C8

OK im finally getting somewhere with this thing! found a bad transistor on the -18v side so now my voltages seem ok. replaced all IC's . so far so good. nice dim light on my current limiter . buttt still no sound. signal stops at SW2 pin 1. dont tell me thats bad now

properly isolated -yes
R85 - good R84 - need to check

in other words U10 keeps going out. oh and i changed R84-85 as recommended to drop to 15v.

ok never mind ,i cant seem to get the -18 working right it keeps coming out -46v. this is getting frustrating.

ok...i got the reg in 18v is good "actually 15.5v" 50v is good . no op amps in and reading 46v across pins 4+8 and Q10 is burning up now WTF!

i posted on ampage...no luck yet. so far i got the 18v and 50v straightened out,but when i pit in fuse 2 on channel 1 the limiter lights up like.....well..a light bulb very bright! so somethings going on after the fuse but not on channel 2 light is barely lit but still no signal passes through.

I'll try to post on ampage later today, but for now i went through and replaced all blown/burned parts except the power transistors since i dont have them yet.and so far so good "no smoke" butttt Q22 is getting really hot within about 5-10seconds of flipping the switch

thanks for all the help so far, it is looking like the ic's are fried so im gonna take a break until the parts come in.

oh boy--- its all kinda screwed up . power transistors are looking bad 18v is bad, time to start replacing parts i guess. ill re post when i get everything replaced and can start testing again.

just to make sure on the power transistors you test base to collector and base to emitter and if thats the case they all look bad "reading about 5 ohms either way ,also with leads reversed"

so i built a light bulb current limiter with a 60w bulb (all i have on hand at the moment)...and when i turn on the velocity to test it im still burning up R28-29 does this mean i need a larger or smaller bulb?