[Elecraft] P3 troubleshooting. Does not power on

[Dave New, N8SBE]

Tom,

Likely the power supply has gone out.  I had a failure like that in my 
early serial number P3, and it took out the front panel board and one of 
my external directional couplers for the TX Mon.  In my case, the 12V to 
one of the low voltages supplies shorted out to 12V.  I got the P3 
repaired at Elecraft, but it cost about half the price of a new P3, due 
to all the damage.  And I didn't know my TX Mon coupler was out until I 
got the unit back, as well, so there's another $200.

I was told that the new power supply board is more robust than the 
original, so this issue shouldn't happen again (fingers crossed).

73,

-- Dave, N8SBE, Hamshack Hotline 590-0971, HamsOverIP 101018, 
AmateurWire 1348

On 2024-08-05 09:42, Tom wrote:
> Hi
> My P3 has all of a sudden stopped powering on.  I am not sure what the 
> issue
> is and I am asking here to see if I can determine where the issue is.
> I have done the usual steps of verifying the power supply, holding down 
> the
> power button for more than 10 seconds with no resolution.
> 
> Using my bench power supply, I see that there is 0 ma current draw at 
> the
> start.  Pressing the power switch will increase the current draw to 
> around
> 260ma as long as the switch is held down.
> 
> The test points on the I/O board (and power supply) show 12V, 5.0 V and
> instead of 3.3V shows 2.6V.
> 
> 
> That is about the extent of my capabilities to trouble shoot from the
> schematic.
> 
> I am wondering if this is just the power supply / IO board?  It would 
> seem
> that Elecraft still has these in stock.
> 
> Thanks, Tom
> Va2fsq.com