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SiriusHardware · 28th Nov 2017, 9:35 pm

Yes, I think so.

A brand new device will be either blank or randomised, and a 'pull' (second hand, taken from some other equipment) will contain nonsense information as far as the keyboard is concerned, therefore the first thing you would need to do after installation is default the unit again, in order to load the new EEPROM with 'sane' values.

There are quite a few package variations, so obviously you'll need to be careful to order the DIP version. I saw one of those for about £1 from a UK supplier. It's not much to gamble on a possible fix.

It's possible that the unit maintains both an EEPROM copy and a RAM copy of the parameters, writing to both whenever you load defaults or make changes, but only reading from the EEPROM (to copy it into the RAM) as the unit initialises after power-up.

Under those circumstances it would be possible for a faulty write to the EEPROM to have no effect for as long as the unit remained powered up following a default, but then if the unit was powered off and then on again, the data, including the 'bad' data stored in the EEPROM, would be loaded into the RAM.

28th Nov 2017, 9:35 pm	#46
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,556	Re: MIDI keyboard fault Yes, I think so. A brand new device will be either blank or randomised, and a 'pull' (second hand, taken from some other equipment) will contain nonsense information as far as the keyboard is concerned, therefore the first thing you would need to do after installation is default the unit again, in order to load the new EEPROM with 'sane' values. There are quite a few package variations, so obviously you'll need to be careful to order the DIP version. I saw one of those for about £1 from a UK supplier. It's not much to gamble on a possible fix. It's possible that the unit maintains both an EEPROM copy and a RAM copy of the parameters, writing to both whenever you load defaults or make changes, but only reading from the EEPROM (to copy it into the RAM) as the unit initialises after power-up. Under those circumstances it would be possible for a faulty write to the EEPROM to have no effect for as long as the unit remained powered up following a default, but then if the unit was powered off and then on again, the data, including the 'bad' data stored in the EEPROM, would be loaded into the RAM.