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M Philbrook M Philbrook is offline
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Default Yamaha dsp-z7 doa

In article ,

The ac line relay cycles for 500mS, without display indications.
This with or without main TX connected.
Housekeeper is live and rises to 13V during the start-up
attempt. Power detect line ok.

Anyone familiar with start-up sequence of this thing?

Looks like you've got to disassemble the whole thing to get
at the processor/control area.

Is it safe to bypass relay, to run up the power gradually?


I have no idea basically what you are talking about except maybe a power
management circuit that isn't getting a watch dog trigger from the CPU ?

Normally those kinds of circuits requie some sort of feed back
information to keep it alive...

I Suppose the proper thing to do is watch that feed back information to
see if this is the case.

In some cases it could be a rather high speed pulse coming from a
Digital timer or CPU. when that stops the circuit will time out and shut

I assume this is what you are referring to ?