e-licktronic Forum

Hey,

my crash was working for a long time and at some point it died, ride is working fine. im not sure when it happened because i didn't use it much. the last 2 things i did was update the firmware and shortened all cables, today i saw on j13 that i mixed up the 2 middle cables, noticed this when i tested the single outs and the hihats came out the crash channel, but no crash out of the hihat channel or master, and with the cables fixed there is still no sound.
i checked the voltages at all marked points and everything looks ok. could putting in those cables wrong damage something?
wish i had sockets for them 5218's :\

that's where i would start, replacing IC64/65 and Q70

can i safely swap IC 54 with IC 62 to check if that's the problem?

i don't want to start desolder something blindly and hope any of you guys have some input

cheers

Data Jam wrote: can i safely swap IC 54 with IC 62 to check if that's the problem?

That's exactly what I would do first: check if your crash EPROM 27C256 is the culprit. I already experienced a dead one in one of my past builts, resulting in a non sounding ride. I found this out by swapping the EPROMs.

Mixing cables on J13 won't do your Nava any harm. It will just result in what you've already experienced: swapped instrument outputs.

the EPROM is working.

scope results (beware i's still electronics novice, just compared ride to crash at the points i think are "the same" !):
no signal at J3 crash out.

C133 signal from ride
C132 no signal from crash

both trigger points getting signal

C128 signal from ride
C127 signal from crash ( "steps" visible" )

Q69 ride "steps" visible on middle (C) pin, E and B also a "signal"
Q71 crash "steps" visible on middle (C) pin, looks to me that there's no signal on E and B

so since i have a signal on C127 similar to C128 and on Q71 only on collector, not similar to Q69, does that mean Q71 died ? i guess not since C127 goes to Q71 collector. and Q70 to Q71 base, where is no signal, so means Q70 died ?

more scope'ing:

R432 signal on the pin towards BassDrum (saw wave)
R430 some signal on both pins same as R436

R439 signal on pin towards sequencer (saw wave)
R436 "same" signal on both pins like R430

looks to me the problem is not the M5218L between those resistors


so with all that and my not existing knowledge of electronics, it looks like the signal before Q70 and to Q71 is ok.

R424 Ride Steps visible
R425 no visible steps

so by now i'm sure its either Q70 or Q71 ... so and now anyone who actually knows what they're talking about, whats your opinion? can you nail it down ? damn right now i don't even remember if i probed Q70 and and Q68 at all... owell next thing to do if by then no one have answered...

solved it was Q70