Hi all!
I’m Ale from Italy. 
I’ve started the MBHP project my goal is a MB64 seq. I’ve made all the PCBs but I’ve populated only the Core and JDM modules.
Also I’ve got the LCD.
I’ve programmed the pic with the LCD test file.
The actual configuration is Core -----> LCD.
The Core has not the 6N148 ic because I havent found it, I’ve to wait after holydays, but the core would work well…if I understood well.
This is what I see When I turn it on:
first line: (all dots on) x 16 characters
second line: blank
Double checked all the parts and the PCBs
All the tensions on the Core are ok.
The cable between core and LCD is ok (I’ve founded the datasheet of the LCD and checked the pinning)
The program is verified and I’ve ereased and reprogrammed the pic 5 times
I’ve tried with 2 different LCDs
The contrast trimmer works from short circuit for 5-10° where the contrast is at the minimum
Light trimmer is Ok.
Jumpers are all on.
I’ve tried to check the xtal oscillation I see a dirty sine of 5 vpp and 20 ms period
Is there a list of check points with the relatives wave shapes and frequencies?
Is there a prg to check the good work of core?
Do I need to populate other PCBs to test the Core with?
I’ve got an oscilloscope and a tester to check the board.
Could someone help me…plllleeeease!!!