K3 assembly voltage regulator failure

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K3 assembly voltage regulator failure

KJ7SOY
Hi everyone! I’m new to the list and to Elecraft radios and HAM in general. Thanks for bearing with me while I learn!

I picked up an unassembled K3 at an auction three weeks ago. It’s been sitting in a box with most of the boards sealed in their anti-static bags since 2009. I’ve hit a snag and I’m hoping someone here can help.

I have the rev B RF board and I’m doing the manual’s resistance tests. Voltage regulators U12 and U13 are both supposed to test at > 150 ohms. U12 passes but U13 tests at 87 ohms. This unit has never been powered up so I suspect it has to be a bad regulator. I can solder a board just fine and assemble PCB’s but I’m not overly comfortable with hardware debugging. Anyone have any ideas how I should proceed? Do I just replace the regulator? Do some other debugging?

Thanks!
73
-Adrian
KJ7SOY

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Re: K3 assembly voltage regulator failure

Don Wilhelm
Adrian,

If you can find no solder bridges, then
Yes, replace the regulator.

73,
Don W3FPR

On 2/13/2021 9:15 PM, KJ7SOY wrote:
> Hi everyone! I’m new to the list and to Elecraft radios and HAM in general. Thanks for bearing with me while I learn!
>
> I picked up an unassembled K3 at an auction three weeks ago. It’s been sitting in a box with most of the boards sealed in their anti-static bags since 2009. I’ve hit a snag and I’m hoping someone here can help.
>
> I have the rev B RF board and I’m doing the manual’s resistance tests. Voltage regulators U12 and U13 are both supposed to test at > 150 ohms. U12 passes but U13 tests at 87 ohms. This unit has never been powered up so I suspect it has to be a bad regulator. I can solder a board just fine and assemble PCB’s but I’m not overly comfortable with hardware debugging. Anyone have any ideas how I should proceed? Do I just replace the regulator? Do some other debugging?
______________________________________________________________
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