Analogue-sequencer

--- In analogue-sequencer@yahoogroups.com, "Colin f" <colin@c...> 
wrote:

morning guys,

> In normal operation the CE line should be 0v, so jumper pin 5 of the
> DS1210 socket to pin 6, then try again.
> Since it's potentially possible the track from pin 6 of the DS1210 
to
> pin 4 of the 74HC138 (U5) could be the problem, check the continuity
> between U5 pin 4 and ground once you've put this jumper in.

i've tried this, as well as a continuity check on all IC's concerned; 
i did find a broken track between pins 7 & 2 of the ds1210, and a few 
other dodgy points i wasn't too sure about which i fixed.
i feel i may be getting somewhere now; jumpered as described (U6 pin8 
> U3 pin1/ U6 pin5 > U6 pin6), i'm still getting the '??/??' above 
bank on the first row in the LCD, but above FTS it displays 'G# !' 
which looks like it refers to a scale to me. 
also, last night when i had the p3 jumpered the same way, i got an 
interesting response; when powering up, i first got a bad chksum 
message and the boot/flash screen. when i then hit boot(f1) i got 
what i believe to be the startup-LED sequence (also the 1st time i 
saw the tricolour leds go red!), the RAM test fail messages followed 
by the (by now) usual '??/?? ?? play' display. when i then re-
uploaded the latest firmware version the LED sequence didn't show 
again and the display went straight to the RAM test fail messages.
also, occasionally, generally when i've just re-jumpered the ds1210, 
i get a part of the Memory Layout screen. last night, with the LED-
sequence thing, i even got a complete memory layout screen for a 
second, including the 3 XxX choices for a short second. it didn't 
last though, and continued to the 'RAM test fail!' display.
i'll wait and see what the new ds1210 is going to do tomorrow.

i also have a few questions;
- what is the usual display after a firmware upload? should it be 
the 'checksum' and 'boot/flash' screen? because i'm just getting a 
blacked out top line..it does respond to the F1 'boot'-key though.
- is there an easy scope-less way to check if the CPU is functioning 
properly? i ask because i'm not getting continually consistent 
responses to stuff im trying; a few times the display'll show me one 
thing, and the next it's something completely different..i'm getting 
kinda concerned that the CPU might be busted.

grtz Chiel