[Elecraft] KPA500 270V Failure

[Bruce Forsberg]

Thanks for the reply but in my case the problem is the voltage multiplier
circuit on the power supply PCB. I just disconnected the HV (~70V) and 270V
lines so they did not go anywhere and the 270V line still only measures 85V.

Thanks
Bruce, WB6IZG

On Sat, Jul 24, 2021 at 8:36 PM Dr. William J. Schmidt <bill at wjschmidt.com>
wrote:

> Here it is.  From Elecraft technical support:
>
> Nominally:
>
> TP2= RX 13.1 TX 0.8
> TP4= RX 3.9 TX 13
>
> From Rene Morris at Elecraft (great guy!).
>
>
>
> Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ
>
> Moderator – North American QRO Group at Groups.IO.
>
> email:  bill at wjschmidt.com
>
>
> -----Original Message-----
> From: Dr. William J. Schmidt <bill at wjschmidt.com>
> Sent: Saturday, July 24, 2021 10:35 PM
> To: 'Bruce Forsberg' <bruce.forsberg at gmail.com>; 'elecraft at mailman.qth.net
> '
> <elecraft at mailman.qth.net>
> Subject: RE: [Elecraft] KPA500 270V Failure
>
> This happens a lot... search the forum for past msgs.  It's not the HV
> power
> supply that is the problem.  That power supply powers the PIN diodes for TR
> and RX... and it is more likely that the PIN diodes shot craps and shorted
> the power supply.  There are two voltage Test Points "TP" on the board
> under
> with the diodes and  you need to check the voltages on those test points.
> That will tell you everything you need to know.  Will post the voltages
> when
> I find them.
>
>
> Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ
>
> Moderator – North American QRO Group at Groups.IO.
>
> email:  bill at wjschmidt.com
>
>
>
>