So after 100+ posts I finally have my 1st mbhp box made - a lil MBSID before i start on the bigger pies (2xMB64 and a LC)…
Voltages all good throughout, and LCD (backlight aint workin tho - do i need to connect the A and K pins on it to nefin?) reads correct - boots with SID v1.4 then goes to:
P: 1 C: 1 D:1
Internal Patch
However, i cant yet hear the beast in action as i dunno how to connect the audio out to a 3 -pole jack socket i have, i’ve tried various ways but have had no luck… am i right in thiniking 2 of the poles have to be bridged? which ones?
Also, can i just connect up the MIDI in/out from the core and tinker about straight away - i.e i dont have to load any sysex files etc…?
Check that your wires running to the backlight pins are round the right way because the backlighting is normally by LED so the current will only flow one way.
The A & K pins are normally connected to the respective pins from the main connector via conductive tracks on the LCD board; Check them with a meter to confirm this, if they are you do not need to hook them up.
You should have a data sheet with your LCD to confirm this?
yeah, lcd2core connection looks okay (displaytech 162). a & k pins have some current going through them…so i guess summin else is a miss…
i am measuring 5v on pins 15/16 ( led + & -) of the lcd, so it should work right? mebbe it’s just gone? i dunno, i did mess about with the lcd prior to putting it into this box…
o well, i whiped in an ltc module with sum ultrbright blue leds that make up for it neway ;), still a mystery tho ???
Still getting a blank screen when i power up (think thats because i may of killed the LCD even tho the backlight lights up). Tried testing with the SID test f/w, and didnt get the choard sound like before…
Checked for track breaks and shorts - all looked okay, even tried swapping the SID, also burnt a new PIC - still no worky tho :(…
Any ideas pls…?
I’m gonna make some new modules, but i’m feelin pretty gutted round about now … :-/
right, stuffed 2 new sid and core modules with new components, checked voltages - all good, burnt sid test f/w and powered up - choard sound played, great ;). But then after powering down and turning back on - silent once again
the failures are very strange, it seems that there is a very dangerous “bug” in your circuit. I hope that you"ve isolated the crystal at the bottom side with a sticky tape? Is there any physical connection between the voltage domain before and after the 7805? Are the jumpers connected properly?
Maybe you should also test some other firmwares in order to ensure that the PIC is still working.
I hope that you"ve isolated the crystal at the bottom side with a sticky tape?
Not with tape, but it’s def not touching any other tracks…
Is there any physical connection between the voltage domain before and after the 7805?
I’m goin from the dc jack to a switch, then to a fuse (1.0A), then to a LED/1k resitor (power LED) as described in the MB64 walkthrough…before feediing both the SID and Core modules…voltages all good on both circuits…
Maybe you should also test some other firmwares in order to ensure that the PIC is still working.
Yeah, ok i’ll do that - but it seems like the same prob Ian was having - I tried using the same pic/sid from the first ones in the new modules, and it worked first time (sid test f/w), then nothing - like in the 1st box, so it seems somthing on the circuit is blowing - mebbe the transistor like u said Ian…
Are you still using the “mirrored” PCB?
Nope, these where on brand new brds i etched n stuffed…
Ian/Dan: is your SID clocked with an additional 1 MHz oscillator or with the PIC?
1mhz osc…
I do not have the same problems with voltage as Dan
Thats the thing, voltages are good now…so it seems we have a same or similar prob…then again, this is electronics - what do i know :P :-X :-/ :-*
Another check to determine if the SID can be accessed by the PIC: at power-on, the reset signal of the SID (Pin #5 of the SID chip) is going low for about three seconds, thereafter it goes to +5V. This can be measured
as i dunno how to connect the audio out to a 3 -pole jack socket i have, i’ve tried various ways but have had no luck… am i right in thiniking 2 of the poles have to be bridged? which ones?
IC1 is fine, IC2 and 3 are also not gettin the +5…
:-/ ???