Guest jason Posted May 17, 2003 Report Share Posted May 17, 2003 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 Quote Link to comment Share on other sites More sharing options...
Guest jason Posted May 17, 2003 Report Share Posted May 17, 2003 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 Quote Link to comment Share on other sites More sharing options...
d2k Posted May 17, 2003 Report Share Posted May 17, 2003 have u adjusted the contrast pot for the LCD?HTH...Dan Quote Link to comment Share on other sites More sharing options...
d2k Posted May 17, 2003 Report Share Posted May 17, 2003 have u adjusted the contrast pot for the LCD?HTH...Dan Quote Link to comment Share on other sites More sharing options...
Guest jason Posted May 17, 2003 Report Share Posted May 17, 2003 Yup. Tried the contrast pot but to no avail - no characters. Quote Link to comment Share on other sites More sharing options...
Guest jason Posted May 17, 2003 Report Share Posted May 17, 2003 Yup. Tried the contrast pot but to no avail - no characters. Quote Link to comment Share on other sites More sharing options...
Captain_Hastings Posted May 18, 2003 Report Share Posted May 18, 2003 But you get midi out? Or nothing at all? Quote Link to comment Share on other sites More sharing options...
Captain_Hastings Posted May 18, 2003 Report Share Posted May 18, 2003 But you get midi out? Or nothing at all? Quote Link to comment Share on other sites More sharing options...
Guest jason Posted May 18, 2003 Report Share Posted May 18, 2003 No I get nothing at all except the backlight of the lcdI 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. Quote Link to comment Share on other sites More sharing options...
Guest jason Posted May 18, 2003 Report Share Posted May 18, 2003 No I get nothing at all except the backlight of the lcdI 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. Quote Link to comment Share on other sites More sharing options...
pay_c Posted May 19, 2003 Report Share Posted May 19, 2003 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? Quote Link to comment Share on other sites More sharing options...
pay_c Posted May 19, 2003 Report Share Posted May 19, 2003 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? Quote Link to comment Share on other sites More sharing options...
TK. Posted May 19, 2003 Report Share Posted May 19, 2003 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. Quote Link to comment Share on other sites More sharing options...
TK. Posted May 19, 2003 Report Share Posted May 19, 2003 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. Quote Link to comment Share on other sites More sharing options...
Guest jason Posted May 19, 2003 Report Share Posted May 19, 2003 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 onJason Quote Link to comment Share on other sites More sharing options...
Guest jason Posted May 19, 2003 Report Share Posted May 19, 2003 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 onJason Quote Link to comment Share on other sites More sharing options...
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