[Elecraft] KRC2 Troubleshooting

[Cady, Fred]

Hi Brian,
I've done a couple of KRC2s and from memory it seems like I never notices the short delay on the LED. It must be pretty short. Also, try holding F1 a couple of times to see if that make it output the 12v starting on 60M. I think that's the way mine is working. I'm not at a computer where the schematic is so I can address the other voltage questions you have.
Good luck. I really like my KRC2.
73,
Fred KE7X
"The Elecraft K3: Design, Configuration, and Operation 2nd Edition"
"The Elecraft KX3 -- Going for the summit"
www.ke7x.com
(Current lulu.com 20% discount code: JUNEBOOKS13)


-----Original Message-----
From: elecraft-bounces at mailman.qth.net [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Brian F. Wruble
Sent: Saturday, June 22, 2013 9:30 PM
To: Elecraft Reflector
Subject: [Elecraft] KRC2 Troubleshooting

I have completed my KRC2 to the point of the smoke test.  No smoke ... I guess that is good.

When I power up, the LED lights (low), but no "short delay while the KRC2 performs diagnostics."

The first test step, "Holding F1" , fails to produce 12 volts at the 60M source, or at any of ther terminals.

I have done about 2 hours of visual inspection.  Every diode is correctly oriented, as are all the ICs and the electrolytics.

I am beginning to wonder if I have the voltage regulator in backward, though it looks exactly right.

TGhe schematic says I should have +5 volts at C14 and +12 V at C13.  I have the reverse.  Before I try to unsolder U3, can someone confirm that those 2 caps are correctly labeled on the schematic?

Also can someone describe the pin numbering for U3.  It really looks like it is in there correctly.

Also, the +5V end of D8 reads +5V (which should be right), but the -12V end of R12 is only -10.4V.

Do these clues suggest anything?

Tnx.  73 de Brian W3BW


*Brian F. Wruble, C.F.A.

*70 is the new 40.*
*
Mail: 1107 Key Plaza, PMB 447 Key West, FL 33040-4077
Summers: P.O.Box 57, 7400 Augustine Herman Highway, Georgetown, MD 21930 eFax  305.768.0278 ______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html