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Old 21st Nov 2017, 3:45 pm   #25
ITAM805
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Join Date: Jul 2010
Location: Folkestone, Kent, UK.
Posts: 2,172
Default Re: MIDI keyboard fault

Hi guys, well of course the k/b is behaving perfectly at present

Notwithstanding, I carried my spare scope onto the lounge floor where this heavyweight sits.The PSU (11.5V) input had lots of ripple on it although the 5V at the regulator was flat with no spikes noted. This could be cured easily with a better supply but as I say, it's working without issue at the moment

Then I tried the MIDI o/p, with the scope screen to -V but I can only get a very weak trace on what I believe is the data pin 4?

AG, there is no shielding or ground wires, the case is metal but isolated from the board.

Hi Kevin, where do I look on the microcontroller? I have the schematic but it comes in at 12mb
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