[Elecraft] FW: FW: [K2] K2 - CONTROL PANNEL FREEZE UP (K7CJA) U6 MEASUREMENTS
CJA
amyescj at earthlink.net
Sat Nov 7 13:24:49 EST 2009
Don:
Thought that I might be using the wrong address so I figured that I would
try this one. Please see blow for my last measurements. Thanks. Chris.
-----Original Message-----
From: Chris Amyes [mailto:amyescj at earthlink.net]
Sent: Thursday, November 05, 2009 7:45 PM
Subject: RE: FW: [Elecraft] [K2] K2 - CONTROL PANNEL FREEZE UP (K7CJA) U6
MEASUREMENTS
Don:
Before removing the CB I checked U6-30 and got 4.92V. I then removed the CB
and checked the following:
RP4 Pins 5&6: Soldering ok. Resistance 81.7K
U6-30 & RP-6/5: Resistance is 90.6k (NOT close to ZERO)
U5 TOP & RP4/6: 0.000
NOTE: R1 on RFB Lifted
BTU, 73
Chris
-----Original Message-----
From: Don Wilhelm [mailto:don at w3fpr.com]
Sent: Thursday, November 05, 2009 4:03 PM
To: Chris Amyes
Subject: Re: FW: [Elecraft] [K2] K2 - CONTROL PANNEL FREEZE UP (K7CJA) U6
MEASUREMENTS
Chris,
You are actually looking for U6-30 (the DOT-PTT signal line) to go to
about 5 volts. Do check Control Board RP4 pins 5 and 6 for good
soldering - while you are at it, check the resistance *between* pins 5
and 6 (should be 82k) . Then check the resistance between U6 pin 30 and
RP6 pin 5 (should be very close to zero) and between the topmost lead of
U5 and RP4 pin 6 - that too should be close to zero.
If those resistance readings are as they should be, put the control
board back in and check the voltage at U6 pin 30 again - it should be
close to 5 volts (pin 29 should also be close to 5 volts).
When you have that condition (U6-30 and U6-29 = 5 volts) correct, put
things back like they were and see what happens, it should be OK.
73,
Don W3FPR
Chris Amyes wrote:
> Don: Here is the result of the first part of your last email. Any
> suggestions? Thanks. Chris.
>
> -----Original Message-----
> From: Chris Amyes [mailto:amyescj at earthlink.net]
> Sent: Wednesday, November 04, 2009 5:41 PM
> To: 'don at w3fpr.com'
> Subject: RE: [Elecraft] [K2] K2 - CONTROL PANNEL FREEZE UP (K7CJA) U6
> MEASUREMENTS
>
> OK.....After removing KSB2, the voltage at U6/30 was .161. I lifted one
> side of R1. U6/30 measured 0, there was no tone and the VFO was unlocked
(I
> could change the frequency).
>
> Chris.
>
> -----Original Message-----
> From: Don Wilhelm [mailto:don at w3fpr.com]
> Sent: Wednesday, November 04, 2009 5:06 PM
> To: Chris Amyes
> Subject: Re: [Elecraft] [K2] K2 - CONTROL PANNEL FREEZE UP (K7CJA) U6
> MEASUREMENTS
>
> Chris,
>
> The voltage on U6-30 is suspicious. Remove the KSB2 first (no jumpers
> necessary for this test, but the K2 will noether receive or transmit)
> and see if it goes to about 5 volts.
> If that does not cure it, next lift one end of R1 on the RF Board
> (remove the left side panel to access it).
> If that still persists, take a careful look at the mic jack and the
> microphone configuration header (whichever mic jack pin the
> configuration header wires to the PTT line).
> Also check the connectors between the Front Panel board pin 4 and its
> mating header on the RF Board as well as RF Board J8 pin 18 and its
> connecting pin on the Control Board. Somewhere in that path, you should
> find the answer to why the DOT/PTT input to U6-30 is sitting at 1.244
> volts. Also be certain that Control Board RP4 pins 5 and 6 are well
> soldered.
>
> After all those checks 'pass muster' and the U6 pin 30 voltage is still
> low, then you may suspect that your firmware chip has a bad input at pin
30.
>
> BTW - ignore my private email suggestion for doing a Master Reset - it
> will not help if U6-30 is at 1.244 volts.
>
> 73,
> Don W3FPR
>
> Chris Amyes wrote:
>
>> Don:
>>
>> The U6 Measurements are as follows:
>>
>> U6-27: 4.65
>> U6-28: 0
>> U6-29: 4.92
>> U6-30: 1.244
>>
>> Chris
>>
>> -----Original Message-----
>> From: Don Wilhelm [mailto:w3fpr at embarqmail.com]
>> Sent: Wednesday, November 04, 2009 9:17 AM
>> To: CJA
>> Cc: elecraft at mailman.qth.net
>> Subject: Re: [Elecraft] [K2] K2 - CONTROL PANNEL FREEZE UP (K7CJA)
>>
>> Chris,
>>
>> The email may have arrived while I was on vacation a week ago - yes, I
>> missed it..
>>
>> Are you certain you measured the gate of Q3 and Q4? Those voltages are
>> normal at the drains of Q3 and Q4 for a K2 in transmit. You can check
>> U6 pin 27 (5 volts during transmit, 0 during receive) and pin 28 (5
>> volts during receive and 0 during transmit).
>>
>> If my guess is correct and you actually measured the drains of Q3 and
>> Q4, then you do have a problem with Q2 or its associated resistors in
>> RP1. You should not have 7 volts on *both* Q1 and Q2 collectors (if you
>> measured the emitters instead, you will find 7 to 8 volts on both.
>>
>> Put that aside for a moment (that information will not solve your
>> primary problem). Does the tone sound anything like sidetone? What I
>> am getting to is that - from all information I have right now, that K2
>> is going into transmit right after a power on. That will make the
>> buttons inactive, and you first need to find out what is causing it to
>> transmit after turning it on. Once that is solved, you can go on to
>> other things.
>>
>> Keep a dummy load connected and the power knob turned down to zero.
>>
>> Measure both U6 pins 29 and 30. Both should be at or near 5 volts - if
>> either of them are close to zero, something is keying your K2 and you
>> need to find the source.
>> OTOH, if both are at 5 volts, the K2 should not be going into transmit
>> (unless the TUNE button is stuck on). If all those things are good, I
>> will recommend (I don't do this often) that you do a Master Reset - hold
>> buttons 4, 5, and 6 in while turning the K2 power on. You will know the
>> reset has been successful if you see Info 201 in the display for a brief
>> time and after that ELECraFT is displayed.
>>
>> You on the complete check-out - look on my website www.w3fpr.com for the
>> K2 alignment document - that is the alignment instructions extracted
>> from the manual. After completing those alignments, then go to the K2
>> Dial Calibration article there and do all the steps including the filter
>> alignment - the Master Reset will have set all your filter and menu
>> setting back to factory default (that is why I do not often recommend a
>> Master Reset, and it rarely solves anything).
>>
>> Make certain your K60XV is properly plugged into its headers and check
>> the secondary menu to be certain the menu parameter for D19 is set to
"Y".
>>
>> 73,
>> Don W3FPR
>>
>>
>>
>> CJA wrote:
>>
>>
>>> Don:
>>> I sent the txt below a while back but it must have gotten lost in
>>> cyberspace. In addition to the measurements below, when I turn on the
K2
>>> now I get the full Elecraft in the LCD, a few clicks from relays and the
>>> speaker as well as a steady medium frequency tone. Nothing works on the
>>> pannel.
>>>
>>> BEGIN EMAIL
>>> I disconnected everything and put it aside for a while. Now I am back
to
>>> it. The measurements are as follows:
>>>
>>> Q1 Collector: 6.77 (Fluctuates, The first time I measured it was 7.6)
>>> Q2 Collector: 7.3 (Fluctuates)
>>> Q3 Gate: .003
>>> Q4 Gate: 7.25
>>>
>>> Shorted Q3? How would it have shorted. I do not see anything that
would
>>> have caused the short.
>>>
>>> In addition, once this issue is sorted out, I would like to go through a
>>> complete tune up procedure. I have the following upgrades in the K2
>>>
> along
>
>>> with the KAT/KPA 100 in a separate enclosure:
>>>
>>> K60XV (No longer shows up on the LCD), KIO2, K160RX, KNB2, KAT2, KSB2,
>>>
>>>
>> KBT2
>>
>>
>>> Is there a stem to stern check-up procedure that I can follow?
>>>
>>> As always, thanks for your assistance.
>>>
>>> Chris Amyes
>>> K7CJA
>>>
>>>
>>> Don Wilhelm-4 wrote:
>>>
>>>
>>>
>>>> Chris,
>>>>
>>>> Keep that dummy load attached, and set the power knob to zero. That K2
>>>> is going into transmit, so you want to protect the PA from harm while
>>>> figuring out what is going on.
>>>>
>>>> Remove anything that may be plugged into either the paddle jack or the
>>>> mic jack and try again.
>>>> If it still goes into transmit, remove the top cover and on the Control
>>>> Board, check the collector of Q1 - it will be between 7.5 and 8 volts
if
>>>>
>
>
>>>> the K2 is in transmit. Also, check the collector of Q2, which should
be
>>>>
>
>
>>>> at 7.5 to 8 volts during receive, If both Q1 and Q2 have voltage on the
>>>> collector, it is trying to transmit and receive at the same time, so
>>>> keep the power on intervals short if that condition is present.
>>>>
>>>> Assuming you have the 8 volts at the collector of Q1 but near zero at
>>>> the collector of Q2 (proper for transmit state), then check pins 29 and
>>>> 30 of Control Board U6 (the microprocessor) - both should be higher
than
>>>>
>
>
>>>> 4 volts (close to 5 volts). If one or both are at a low voltage, there
>>>> is something holding the dot or dash lines low, and you should be able
>>>> to locate it with an ohmmeter and visual inspection for solder bridges
>>>> or stray wire clippings.
>>>>
>>>> If you have both transmit and receive 8 volt lines (collectors of CB Q1
>>>> and Q2), then check the gates of CB Q3 and Q4. For receive, the gate
of
>>>>
>
>
>>>> Q4 should be high (4.5 to 5 volts), and the gate of Q3 should be near
>>>> zero. If these last conditions are true, the microprocessor outputs
for
>>>>
>
>
>>>> transmit and receive are correct and the most likely failure is a
>>>> shorted Q3.
>>>>
>>>> Let us know the results of those tests.
>>>>
>>>> 73,
>>>> Don W3FPR
>>>>
>>>> CJA wrote:
>>>>
>>>>
>>>>
>>>>> I have a K2 with a KPA100 and KAT100 in a separate enclosure. It had
>>>>> been
>>>>> working on my lossey loop but I decided to try a ground mounted Hi-Q
>>>>> 4/160.
>>>>> After connecting the antenna, I began trying to tune to the various
>>>>> bands.
>>>>> It seemed to be tuning to a low SWR when the control panel just froze
>>>>>
>>>>>
>> up.
>>
>>
>>>>> The VFO would not change the freq and none of the buttons functioned.
>>>>>
> I
>
>>>>> turned it off and on several times and came up with the full elecraft
>>>>>
> in
>
>>>>> the
>>>>> LCD and then the last freq I was on. The control panel was still
>>>>>
>>>>>
>> frozen.
>>
>>
>>>>> I
>>>>> then tried to reset. That did not work. Now it just goes through the
>>>>> POST
>>>>> (full elecraft in the LCD) and seems to go into transmit (dummy load
>>>>> connected) with a high pitched tone and hangs there. Any suggestions
>>>>> would
>>>>> be greatly appreciated. 73, Chris Amyes, K7CJA
>>>>>
>>>>>
>>>>>
> ------------------------------------------------------------------------
>
>>>>> No virus found in this incoming message.
>>>>> Checked by AVG - www.avg.com
>>>>> Version: 8.5.409 / Virus Database: 270.14.1/2407 - Release Date:
>>>>>
>>>>>
>> 10/01/09
>>
>>
>>>>> 06:34:00
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>> ______________________________________________________________
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>>>>
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>>>>
>>>>
>>>>
>>>>
>>>
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>>>
>>>
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> 11/04/09
>
>>>
>>>
>> 07:37:00
>>
>>
>>>
>>>
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>>>
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> 11/04/09 07:37:00
>
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