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KX1 appears dead after KXB3080 PCB installed... ...Help please!

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ShawnMorrow

KX1 appears dead after KXB3080 PCB installed... ...Help please!

I have been using my KX1 for the past year or so. This past weekend I
decided to install the KXB3080 option. Performing the checkout step after
the KXB3080 PCB install failed normal operation! Nothing works. My KX1 now
appears to be mostly dead. :-0

I am hoping the collective wisdom of the list can confirm or suggest other
possibilities I should check out to try to revive my KX1. The other thing I
fear is multiple component failures. Please help! I am anxious to return
to the air! (Believe it or not my KX is my station!)

Here is the run down:

The mods to the KX1 PCB (Part 1) went well and passed all the re-alignment
checks.

I installed the KXB3080 PCB fairly easily. (I did have some problems
removing solder from the plated through hole for L7 near R2. Ultimately I
also got solder in the adjacent G through hole as well. I eventually got
these cleared.)

Upon performing the check out step towards the end of the this section (Part
II in the KXB3080 manual) I experienced the following:

Current drain 36mA @ 13V - OK.
LED lit up momentarily, 1 or 2 segments missing, then went dark. (!!)

Subsequent attempts to power up go like this:
NO LED
NO Relay Clicks at power up
Current: 36mA @ 13V
Buttons - unresponsive
White Noise from earphones, volume works
RF Gain and Filter have no affect on the audio
(I did not check RF out.)

I double re-checked the install. No anomalies were noted.

I opened up the trouble shooting section of the KX1 Manual:

Section 00 - all ok

Section 20 - all regulators are right on: 6V, 5V, 2.7V

Section 26 - U1 Voltage Levels (w/i 10%) Measured @ 13V

Pin Spec Meas Pin Spec Meas
1 5.0 5.0 15 0 0
2 5.0 5.0 16 0 0
3 4.6 5.0 17 0 0
4 4.9 5.0 18 0 0
5 4.9 5.0 19 0 0
6 3.4 4.3 << 20 5.0 5.0
7 1.4 0 << 21 5.0 0 <<
8 0 0 22 5.0 4.7
9 .8 .8 23 4.9 4.7
10 .9 .9 24 5.0 4.8
11 0 0 25 5.0 4.8
12 0 0 26 4.7 4.8
13 5.0 5.0 27 5.0 4.8
14 0 5.0 << 28 5.0 4.8

Measurements marked with "<<" are outside the 10% tolerance limit!! Is it
fair to conclude U1 is toast!?!?

At this point I think I probably "fried" U1 during the install. Since its
winter and pretty dry in doors I am guessing ESD got it. This despite using
an anti-static mat, ...and wrist strap -- *most* of the time. :(

I am hoping the collective wisdom of the list can confirm or suggest other
possibilities I should check out before replacing U1. The other thing I
fear is that perhaps other components were damaged in the process.

What say you??

Regards, Shawn Morrow
W4SDM

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Shawn Morrow
W4SDM

Don Wilhelm-4

Re: KX1 appears dead after KXB3080 PCB installed... ...Help please!

Shawn,

KX1 display problems are usually caused by U1, so your suspicions are on
target.
Before doing anything else, be certain U1 is properly seated in its
socket. You should have almost all of the narrow part of the pins
inserted in the socket. If that is not the case, press it in - it does
take a bit of pressure to seat U1.

OTOH, if U1 is already fully seated, you should request a replacement
for [hidden email].

On the voltages you find out of bounds, pins 6 and 7 are inputs to U1 -
and that means something other than U1 is the cause for the voltage
being abnormal. In particular, the pin 6 voltage is sourced at U5 pin
2. Check that pin - if the voltage there is 1.4 volts, but is zero at
U1 pin 6, check your soldering.

The soldering on the KX1 is more critical than most of the other
Elecraft kits due to the high density of parts. Your solder connections
should look like the figures in the Soldering Tutorial at the Elecraft
Builder's Resource page.

If soldering is the problem, it would be wise to wick away any excess
solder and re-solder with a 750 deg F iron making certain the solder
flows on each and every solder pad.

73,
Don W3FPR

73,
Don W3FPR

Shawn Morrow wrote:

> I have been using my KX1 for the past year or so. This past weekend I
> decided to install the KXB3080 option. Performing the checkout step after
> the KXB3080 PCB install failed normal operation! Nothing works. My KX1 now
> appears to be mostly dead. :-0
>
> I am hoping the collective wisdom of the list can confirm or suggest other
> possibilities I should check out to try to revive my KX1. The other thing I
> fear is multiple component failures. Please help! I am anxious to return
> to the air! (Believe it or not my KX is my station!)
>
> Here is the run down:
>
> The mods to the KX1 PCB (Part 1) went well and passed all the re-alignment
> checks.
>
> I installed the KXB3080 PCB fairly easily. (I did have some problems
> removing solder from the plated through hole for L7 near R2. Ultimately I
> also got solder in the adjacent G through hole as well. I eventually got
> these cleared.)
>
> Upon performing the check out step towards the end of the this section (Part
> II in the KXB3080 manual) I experienced the following:
>
> Current drain 36mA @ 13V - OK.
> LED lit up momentarily, 1 or 2 segments missing, then went dark. (!!)
>
> Subsequent attempts to power up go like this:
> NO LED
> NO Relay Clicks at power up
> Current: 36mA @ 13V
> Buttons - unresponsive
> White Noise from earphones, volume works
> RF Gain and Filter have no affect on the audio
> (I did not check RF out.)
>
> I double re-checked the install. No anomalies were noted.
>
> I opened up the trouble shooting section of the KX1 Manual:
>
> Section 00 - all ok
>
> Section 20 - all regulators are right on: 6V, 5V, 2.7V
>
> Section 26 - U1 Voltage Levels (w/i 10%) Measured @ 13V
>
> Pin Spec Meas Pin Spec Meas
> 1 5.0 5.0 15 0 0
> 2 5.0 5.0 16 0 0
> 3 4.6 5.0 17 0 0
> 4 4.9 5.0 18 0 0
> 5 4.9 5.0 19 0 0
> 6 3.4 4.3 << 20 5.0 5.0
> 7 1.4 0 << 21 5.0 0 <<
> 8 0 0 22 5.0 4.7
> 9 .8 .8 23 4.9 4.7
> 10 .9 .9 24 5.0 4.8
> 11 0 0 25 5.0 4.8
> 12 0 0 26 4.7 4.8
> 13 5.0 5.0 27 5.0 4.8
> 14 0 5.0 << 28 5.0 4.8
>
> Measurements marked with "<<" are outside the 10% tolerance limit!! Is it
> fair to conclude U1 is toast!?!?
>
> At this point I think I probably "fried" U1 during the install. Since its
> winter and pretty dry in doors I am guessing ESD got it. This despite using
> an anti-static mat, ...and wrist strap -- *most* of the time. :(
>
> I am hoping the collective wisdom of the list can confirm or suggest other
> possibilities I should check out before replacing U1. The other thing I
> fear is that perhaps other components were damaged in the process.
>
> What say you??
>
> Regards, Shawn Morrow
> W4SDM
>
>

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ShawnMorrow

Re: KX1 appears dead after KXB3080 PCB installed... ...Help please!

Thanks Don.

At one point I actually reseated U1 just to be sure so I think I'm good
there.

Checked out U5 as you suggested. Here is what I found:

Pin Spec Meas Pin Spec Meas
1 1.39 0 << 5 4.44 5.8 <<
2 1.39 0 << 6 5.57 5.7
3 0 0 7 4.96 5.2
4 4.44 5.8 << 8 5.62 5.8

So this sort of implies that U5 is shot as well, no?? Do these readings
suggest any thing else I should check into?? (These results also got me
looking downstream from pins 14 and 22 on U1 that also read abnormal.)

I am guessing I should request a new U5 too?

Any other insights??

Thanks for all the help. It is appreciated.

Regards,
Shawn Morrow
W4SDM

______________________________________________________________
Elecraft mailing list
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Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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Shawn Morrow
W4SDM

Don Wilhelm-4

Re: KX1 appears dead after KXB3080 PCB installed... ...Help please!

Shawn,

Yes - the NE612 is quite a hardy device. Try removing Q9 from the board
and see if the voltage at U5 pins 1 and 2 go up to the vicinity of 1.4
volts. If, no, then remove C8 and measure again - if still not 1.4
volts, replace U5 - or look for the solder bidge that is shorting the
product detector input.

73,
Don W3FPR

Shawn Morrow wrote:

> Thanks Don.
>
> At one point I actually reseated U1 just to be sure so I think I'm good
> there.
>
> Checked out U5 as you suggested. Here is what I found:
>
> Pin Spec Meas Pin Spec Meas
> 1 1.39 0 << 5 4.44 5.8 <<
> 2 1.39 0 << 6 5.57 5.7
> 3 0 0 7 4.96 5.2
> 4 4.44 5.8 << 8 5.62 5.8
>
> So this sort of implies that U5 is shot as well, no?? Do these readings
> suggest any thing else I should check into?? (These results also got me
> looking downstream from pins 14 and 22 on U1 that also read abnormal.)
>
> I am guessing I should request a new U5 too?
>
> Any other insights??
>
> Thanks for all the help. It is appreciated.
>
> Regards,
> Shawn Morrow
> W4SDM
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
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> Please help support this email list: http://www.qsl.net/donate.html
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>

ShawnMorrow

Re: KX1 appears dead after KXB3080 PCB installed... ...Help please!

I want to close out this thread now that my KX1 is back on the air on 80, 40, 30, and 20 meters.

I was doing another close visual before following up on Don's advice to remove Q9. During that process I must of dislodged something that was causing a short in the vicinity of T2. There were a couple of through holes I had difficulty clearing to mount T2 and I think perhaps there was solder ball or something that was hidden by T2. Once dislodged everything came "back to life". Needless to say I was quite relieved!!

So, this re-enforces Don's advice to check the soldering closely and perhaps to pay attention to any solder debris that might be left "laying around."

Don - thanks for the tips and assistance to help me through this.

73, W4SDM

Shawn Morrow
Fairfax, VA

Shawn Morrow
W4SDM

Bill Johnson-9

Re: KX1 appears dead after KXB3080 PCB installed... ...Help please!

Been there done that as a test builder. This is one complex update that
needs extreme care, even for those of us who might proclaim we know what we
are doing.

73,

Bill
K9YEQ
K2 #35; KX1 #35; K3 #1744; mini mods

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of ShawnMorrow
Sent: Tuesday, February 17, 2009 6:41 PM
To: [hidden email]
Subject: Re: [Elecraft] KX1 appears dead after KXB3080 PCB installed...
...Help please!

I want to close out this thread now that my KX1 is back on the air on 80,
40,
30, and 20 meters.

I was doing another close visual before following up on Don's advice to
remove Q9. During that process I must of dislodged something that was
causing a short in the vicinity of T2. There were a couple of through holes
I had difficulty clearing to mount T2 and I think perhaps there was solder
ball or something that was hidden by T2. Once dislodged everything came
"back to life". Needless to say I was quite relieved!!

So, this re-enforces Don's advice to check the soldering closely and perhaps
to pay attention to any solder debris that might be left "laying around."

Don - thanks for the tips and assistance to help me through this.

73, W4SDM

Shawn Morrow
Fairfax, VA

-----

Shawn Morrow
W4SDM
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______________________________________________________________
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Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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