[Elecraft] KAT500 refuses to turn on

[Bob McGraw K4TAX]

I'd start by opening the box and check the input and output of the 
regulator, U4, being a LM7805.   Should have ~12V on the input and 5V on 
the output.  If there is not 12V on the input then check both sides of 
the diode, D8, which is in series with the 12V input.  Also there is an 
inductor/choke L9 in series with the 12 volt line to the LM7805.

If the LM7805 does not have 5V on the output, either it has failed or 
there is a short which is pulling the 5V line to zero. Schematics are 
available and the rest depends on your trouble shooting skills.

Otherwise, obtain an RA from Elecraft Tech Support.

73

Bob, K4TAX


On 2/14/2019 8:00 AM, Jim Douglas via Elecraft wrote:
> Hi All,I have the K line here. I was listening to a QSO and out of the blue my KAT500 lost power.I disconnected everything from the KAT500 and then reconnected. The power plug has 12 volts so that is not the problem.The KAT500 was set up to turn on automatically when I turned on the power supply and now that does not work anymore.When I press the mode button to turn on the tuner that does not work now either. Where do I start looking?Thanks, Jim Douglas  K2ZF
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