LCD display not working...

angusmack wrote:I have exactly the same issue:

Any ideas on this please? Everything else works as far as I can tell, without a display i.e. I can 'tap' all instruments using the buttons but no display.

I’ve just finished a 1.02 build (yet to receive/populate the polystyrene caps in the cymbals) but I’m getting this exact same problem. Top row all blocks and nothing to display. Continuity is all there on the display to Atmega as per Klangs diagram. Any suggestions as to what else to check?

Have you checked continuity for the tracks between the LCD and Atmega on both sides of the board? I had this weird issue where one side would register fine and the other didn't. That and doing the init EPROM step seemed to fix it eventually.

angusmack wrote:Have you checked continuity for the tracks between the LCD and Atmega on both sides of the board? I had this weird issue where one side would register fine and the other didn't. That and doing the init EPROM step seemed to fix it eventually.

Thanks for the reply angusmack. Yes, I've checked both sides and continuity is there. I get some odd behaviour when trying to power on the unit, sometimes all LEDs will be lit, sometimes only partial, etc. If I hold down Enter and power on, usually all LEDs will be lit but I cannot get any voltage measurement at TP1 with any range on TM2.

I've also tried to hold Start and Stop at boot to try and init the EEPROM but again, I don't seem to get any functionality. How long should I be waiting? Any other indication of the issue from the symptoms I've mentioned?

I've ordered a new EEPROM just in case it's that. The build was clean and I've reflowed a few suspect points on the sequencer board to no avail. I've yet to try any sounds.

I should also mention all voltages in the sequencer section are all OK.

With all ICs removed from the sequencer section except Atmega and eeprom, should I see a valid display on the LCD? I’m still seeing top row blocks.

Bump!