rbv2 Posted February 5, 2014 Report Share Posted February 5, 2014 hi all, build my sammichSID 3 years ago with no problems. now i got it back from a friend and the backlight of the display was not working anymore. i tried to find out whats wrong and found the display backlight is working when powered from a battery. during testing with an led on pins B-/B+ i somehow shorted the little sammichSID. when i turn on the unit all i can see now is the row of black boxes on the screen like without firmware. it is still doing the start sound and the flashing led sequence in the beginning. I tried to re-upload the firmware but nothing changed. what else can i try? please help. thanks Quote Link to comment Share on other sites More sharing options...
TK. Posted February 7, 2014 Report Share Posted February 7, 2014 For me it looks like a connection problem between PIC and LCD, because the PIC and the MIDIbox SID application is still running. Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
rbv2 Posted February 8, 2014 Author Report Share Posted February 8, 2014 thank you Thorsten. i soldered all the joints again on the lcd connector of the cs-pcb and base-pcb, the pic socket and the trimpots.. but with no success, still black boxes.. anything else i can do? Quote Link to comment Share on other sites More sharing options...
latigid on Posted February 9, 2014 Report Share Posted February 9, 2014 You might've fried your LCD, that's easy to do. You describe shorting the backlight, well if you've applied a high current across any of the data lines that could knock out some of the circuitry. Do you have the option of using a second backlight for a test? If so, be sure you don't have any shorts that might repeat the process and outcome. Quote Link to comment Share on other sites More sharing options...
rbv2 Posted February 9, 2014 Author Report Share Posted February 9, 2014 thanks for your reply. unfortunately its the only lcd i have. the lcd is working i guess because it looks like before i uploaded the sid application. black squares in the upper row. is there another way to test the lcd? how do i check the connections between lcd and pic? thanks Quote Link to comment Share on other sites More sharing options...
sneakthief Posted February 10, 2014 Report Share Posted February 10, 2014 Try the MIOS8 LCD test application: http://www.ucapps.de/mios/lcd_interconnection_test_v2.zip If that doesn't work, try uploading MIOS 1.9g again: http://www.ucapps.de/mios/mios_v1_9g.zip Please read the instructions carefully before uploading and make sure to choose the right version. Quote Link to comment Share on other sites More sharing options...
rbv2 Posted February 11, 2014 Author Report Share Posted February 11, 2014 i did the lcd test. all pins show the correct voltage but the lcd doesnt change.. so is it broken like latigid on said? after that i uploaded the mios 1.9g and sammich.hex again, application is up and running but .. still black squares :( is it time to buy new lcd? thanks sneakthief regards from leipzig :) Quote Link to comment Share on other sites More sharing options...
Hawkeye Posted February 12, 2014 Report Share Posted February 12, 2014 It is probably fried - but before you replace it, give the contrast pot a try... Solid black boxes sometimes are caused by wrong LCD contrast. But I fear the short sent it to LCD nirvana :-) Many greets, Peter Quote Link to comment Share on other sites More sharing options...
rbv2 Posted February 12, 2014 Author Report Share Posted February 12, 2014 (edited) thank you hawkeye! but i still have no clue why the backlight was not working (before shorted).. because all the voltage seems to be correct and the backlight lights up when powered from external battery.. found this on ebay: http://www.ebay.de/itm/DISPLAYTECH-202A-BA-BC-LCD-532-6571-/321314061515?pt=UK_BOI_Industrial_Automation_Control_ET&hash=item4acfcf7ccb does it work as replacement or is there any difference regarding the pins? Edited February 12, 2014 by rbv2 Quote Link to comment Share on other sites More sharing options...
ilmenator Posted February 12, 2014 Report Share Posted February 12, 2014 Hope you used a current limiting resistor when connecting the backlight to the battery?! Quote Link to comment Share on other sites More sharing options...
rbv2 Posted February 12, 2014 Author Report Share Posted February 12, 2014 yes i did :) thank you Quote Link to comment Share on other sites More sharing options...
rbv2 Posted February 12, 2014 Author Report Share Posted February 12, 2014 It is probably fried - but before you replace it, give the contrast pot a try... Solid black boxes sometimes are caused by wrong LCD contrast. But I fear the short sent it to LCD nirvana :-) Many greets, Peter unfortunately its not the contrast.. Quote Link to comment Share on other sites More sharing options...
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