[Elecraft] FUSE BLOWN AND NOW WHAT?

Manuel Wilches manuelwilches at arnet.com.ar
Sat Apr 1 06:58:45 EST 2006


Good morning Don:
I forgot to tell you I have a RIGRUNNER 4012 with my small power supply for 
the K2. Well, it had blown a fuse and I did not realise it. When I checked 
everything this morning, after your email, the K2 is ON with no problems. 
Thank you for the fuses!
Many many thanks Don
73
Manuel
LU5OM
CT4IK

----- Original Message ----- 
From: "Don Wilhelm" <w3fpr at earthlink.net>
To: "Manuel Wilches" <manuelwilches at arnet.com.ar>
Sent: Saturday, April 01, 2006 2:15 AM
Subject: RE: [Elecraft] FUSE BLOWN AND NOW WHAT?


> Manuel,
>
> Given those readings, your diodes are OK.
>
> Check your Power Supply and its cable to the K2.  With the K2 powered ON,
> what is the voltage at your power supply terminals?  What is the voltage 
> at
> the anode of D10?  If the two are substantially different, then you should
> re-check your power cable for good solder connections at both ends.
>
> 73,
> Don W3FPR
>
>> -----Original Message-----
>> From: Manuel Wilches [mailto:manuelwilches at arnet.com.ar]
>> Sent: Friday, March 31, 2006 11:48 PM
>> To: w3fpr at arrl.net
>> Subject: Re: [Elecraft] FUSE BLOWN AND NOW WHAT?
>>
>>
>> Don:
>> Thank you very much
>> R seems to be higher than 500 ohms. I am not really sure...I get
>> all kinds
>> of readings...voltage readings seem to be more reliable with my DMM.
>> When I switch ON it is infinite (1)..I get a "1" in all ranges
>> I checked F1 and I get continuity when I switch it on
>> I checked voltages as follows:
>> Cathode of D10= 2.40
>> Anode of D10= 2.40
>> Cathode of D12= 2.31
>> Anothe of D12=0
>> However, the power supply is delivering 12.50 v but, when I switch ON my
>> reading is only 2.31/2.40 v at the input of the rig. This doesn't sound
>> right to me...it should be 12.5 v right?
>>
>> Is there a reliable way to test the diodes without desoldering them?
>> Thank you
>> 73
>> Manuel
>> LU5ON
>>
>> ----- Original Message -----
>> From: "Don Wilhelm" <w3fpr at earthlink.net>
>> To: "Manuel Wilches" <manuelwilches at arnet.com.ar>;
>> <elecraft at mailman.qth.net>
>> Sent: Friday, March 31, 2006 10:57 PM
>> Subject: RE: [Elecraft] FUSE BLOWN AND NOW WHAT?
>>
>>
>> > Manuel,
>> >
>> > It is only a guess, but I would expect that the auto-resetting
>> fuse in the
>> > K2 is open, and possibly Doide D12 is shorted, or both.
>> >
>> > With the K2 power switch in the ON position, check the resistance to
>> > ground
>> > from the cathode of D10, you should measure more than 500 ohms
>> - if it is
>> > less than 500, turn the power switch to OFF and check again,
>> this time the
>> > resistance should be infinite.  If you have a low resistance with the
>> > power
>> > switch in the OFF position, look for a short to ground (or a
>> shorted D12).
>> >
>> > If you do find a high resistance with the switch off, then connect your
>> > power supply and measre voltages - first at the anode of D10, then the
>> > cathode - next check at the center contacts of the power switch.  If 
>> > you
>> > have voltage at the cathode of D10 and none at the power switch, F1 is
>> > likely open.
>> >
>> > Good luck and let us know what you find.
>> >
>> > 73,
>> > Don W3FPR
>> >
>> >> -----Original Message-----
>> >>
>> >> Hello everyone:
>> >> this time I have to come forward and confess with full exposure
>> >> in broad day
>> >> light. I made a terrible mistake!
>> >>
>> >> My KPA100 tested beautifully untill I got to the 20A power supply
>> >> test (page
>> >> 45). As I turned on the K2 (#8 step) nothing happened. I checked
>> >> and I had
>> >> blown a fuse (the one that comes with the kit). I switched off
>> everything
>> >> and went back to figure 32 (page 38)...I had reversed the wires
>> >> on j4 when I
>> >> soldered them on the KPA100 board.
>> >>
>> >> As I was taking my time to unsolder the cables, clean the pads etc. I
>> >> thought I could  turn on the K2 on its own (as before) with my
>> low power
>> >> supply and nothing else attached to it. Well here comes the 
>> >> suprise...I
>> >> cannot turn on the K2 at all. I have the 13,0 volts allright,
>> >> coming out of
>> >> my small PS but nothing happens. What did I blow away?
>> >>
>> >> J4 was plugged in P3, of course, when I blew the fuse.
>> >>
>> >> Your comments and recommendations will be very much appreciated.
>> >>
>> >> Thank you
>> >> 73
>> >> Manuel Wilches
>> >> LU5OM
>> >> CT4IK
>> >>
>> >>
>> >
>>
>>
>>
>> --
>> No virus found in this incoming message.
>> Checked by AVG Free Edition.
>> Version: 7.1.385 / Virus Database: 268.3.3/298 - Release Date: 3/30/2006
>>
>>
> 



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