Midibox64 (2 Ain 2 Din and bankstick all disconnected). LCD, Midi in out connected to core.
PIC Burned correctly.
When I switch on the LCD backlight comes on but I get no character display or midi messages.
I have noted the voltage between pin 1 - pin 12 of the pic is 4.5v but I don’t know how to increase this.
The LCD is wired correctly and all other voltages check out.
Any ideas?
Do I need to do anything with the connections that are not used eg. J8 and J11
Midibox64 (2 Ain 2 Din and bankstick all disconnected). LCD, Midi in out connected to core.
PIC Burned correctly.
When I switch on the LCD backlight comes on but I get no character display or midi messages.
I have noted the voltage between pin 1 - pin 12 of the pic is 4.5v but I don’t know how to increase this.
The LCD is wired correctly and all other voltages check out.
Any ideas?
Do I need to do anything with the connections that are not used eg. J8 and J11
have u adjusted the contrast pot for the LCD?
HTH…
Dan
have u adjusted the contrast pot for the LCD?
HTH…
Dan
Yup. Tried the contrast pot but to no avail - no characters.
Yup. Tried the contrast pot but to no avail - no characters.
But you get midi out? Or nothing at all?
But you get midi out? Or nothing at all?
No I get nothing at all except the backlight of the lcd
I have been testing the board and think the problem may be with 4.5v between pin 1 - pin 12 of the pic causing the pic not to boot but I cannot find the solution.
No I get nothing at all except the backlight of the lcd
I have been testing the board and think the problem may be with 4.5v between pin 1 - pin 12 of the pic causing the pic not to boot but I cannot find the solution.
The 7805 is supplying the 4,5 V. So this means the 7805 isnt getting enough voltage. Put in about 9V. Normally regulated power supplies are loosing a little voltage if running at higher currents (mine is set to 9 V and delievers only about 7,8 V at 250 mA).
Then there should be about 4,8V-5V at those two pins and the rest of the MB.
Another question (if it still doesnt work). The leds of the DOUTX4 should play some “pattern” (theyre lighting up from the middle to the outer ranges and back four times). Do they do that?
The 7805 is supplying the 4,5 V. So this means the 7805 isnt getting enough voltage. Put in about 9V. Normally regulated power supplies are loosing a little voltage if running at higher currents (mine is set to 9 V and delievers only about 7,8 V at 250 mA).
Then there should be about 4,8V-5V at those two pins and the rest of the MB.
Another question (if it still doesnt work). The leds of the DOUTX4 should play some “pattern” (theyre lighting up from the middle to the outer ranges and back four times). Do they do that?
Hi Jason,
the PIC should already run with 4.5V. Maybe it’s better to check the crystal first, it has to be isolated from the copper tracks with a tape in order to avoid shorts. This picture shows, how it has to be done for MIDIbox Plus, but for the MBHP core module it’s the same:
Best Regards, Thorsten.
Hi Jason,
the PIC should already run with 4.5V. Maybe it’s better to check the crystal first, it has to be isolated from the copper tracks with a tape in order to avoid shorts. This picture shows, how it has to be done for MIDIbox Plus, but for the MBHP core module it’s the same:
Best Regards, Thorsten.
Hi,
I will try the increased voltage - but had already isolated the crystal from the board. Though if thats the general area I should be looking in I may change the crystal but firstly I will change the two 33pf caps as I think I cooked them with the soldering iron when I was putting them in and this may be causing the problem.
Thanks for your tips I’ll let you know how I get on
Jason
Hi,
I will try the increased voltage - but had already isolated the crystal from the board. Though if thats the general area I should be looking in I may change the crystal but firstly I will change the two 33pf caps as I think I cooked them with the soldering iron when I was putting them in and this may be causing the problem.
Thanks for your tips I’ll let you know how I get on
Jason
