|
I'm having some trouble with a battery change in a 3468 DMM. You would think I could handle that without incident! I kept 3 volts on the terminals while soldering in the new battery but one of the leads slipped off and there went the calibration. No problem - I can calibrate it again or so I thought. The display flashed "error 1" (ram error)and then went blank. It's been blank ever since despite all the resetting procedures I've tried. Could corrupt ram cause this? Or is could I have somehow damaged the controller? Any thoughts would be appreciated.
|
I tried to remove and read the contents of the ROM on my 3478A. In the
process, I apparently shorted the 5 V line to ground, which somehow killed
the contents of the CALRAM. In any event, there was a message about
Calibration. I then replaced the battery and went through the recalibration
steps and all was well.
According to the manual for the 3468A, Error 1 is 'Calibration RAM Error'.
Error 2 is 'RAM Error'.
I suspect that the issue is that you lost the RAM contents for the
Calibration RAM. Have you tried to calibrate the unit? Have you checked
the power supplies?
The alternative is once the lead slipped off, it 'connected' to something
else and took out something. Was it the + or - lead?
Sounds like you need to go the service manual and start with the trouble
shooting section, probably Service Group E, and go from there.
Good luck.
Joe
From: hp_agilent_equipment@...
[mailto:hp_agilent_equipment@...] On Behalf Of xyloeye
Sent: Thursday, January 17, 2013 2:06 PM
To: hp_agilent_equipment@...
Subject: [hp_agilent_equipment] HP 3468 DMM battery change
I'm having some trouble with a battery change in a 3468 DMM. You would think
I could handle that without incident! I kept 3 volts on the terminals while
soldering in the new battery but one of the leads slipped off and there went
the calibration. No problem - I can calibrate it again or so I thought. The
display flashed "error 1" (ram error)and then went blank. It's been blank
ever since despite all the resetting procedures I've tried. Could corrupt
ram cause this? Or is could I have somehow damaged the controller? Any
thoughts would be appreciated.
|
Thanks for your reply. You're right, error 1 is calibration RAM. I tried to calibrate it but since the display is dead, it's hard to do. When the lead fell off I'm positive it didn't touch anything else. I just can't figure out how disconnecting the battery would cause a dead display.
Ken
toggle quoted message
Show quoted text
--- In hp_agilent_equipment@..., "J. L. Trantham" wrote:
I tried to remove and read the contents of the ROM on my 3478A. In the
process, I apparently shorted the 5 V line to ground, which somehow killed
the contents of the CALRAM. In any event, there was a message about
Calibration. I then replaced the battery and went through the recalibration
steps and all was well.
According to the manual for the 3468A, Error 1 is 'Calibration RAM Error'.
Error 2 is 'RAM Error'.
I suspect that the issue is that you lost the RAM contents for the
Calibration RAM. Have you tried to calibrate the unit? Have you checked
the power supplies?
The alternative is once the lead slipped off, it 'connected' to something
else and took out something. Was it the + or - lead?
Sounds like you need to go the service manual and start with the trouble
shooting section, probably Service Group E, and go from there.
Good luck.
Joe
From: hp_agilent_equipment@...
[mailto:hp_agilent_equipment@...] On Behalf Of xyloeye
Sent: Thursday, January 17, 2013 2:06 PM
To: hp_agilent_equipment@...
Subject: [hp_agilent_equipment] HP 3468 DMM battery change
I'm having some trouble with a battery change in a 3468 DMM. You would think
I could handle that without incident! I kept 3 volts on the terminals while
soldering in the new battery but one of the leads slipped off and there went
the calibration. No problem - I can calibrate it again or so I thought. The
display flashed "error 1" (ram error)and then went blank. It's been blank
ever since despite all the resetting procedures I've tried. Could corrupt
ram cause this? Or is could I have somehow damaged the controller? Any
thoughts would be appreciated.
|
You may need to disconnect the battery again to allow the RAM to "zero" out. Well at least not be in it's present state.
Just a thought,
Jeff
toggle quoted message
Show quoted text
On 1/17/2013 5:16 PM, xyloeye wrote:
Thanks for your reply. You're right, error 1 is calibration RAM. I tried to calibrate it but since the display is dead, it's hard to do. When the lead fell off I'm positive it didn't touch anything else. I just can't figure out how disconnecting the battery would cause a dead display.
Ken
--- In hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com>, "J. L. Trantham" wrote:
I tried to remove and read the contents of the ROM on my 3478A. In the
process, I apparently shorted the 5 V line to ground, which somehow
killed
the contents of the CALRAM. In any event, there was a message about
Calibration. I then replaced the battery and went through the recalibration
steps and all was well.
According to the manual for the 3468A, Error 1 is 'Calibration RAM Error'.
Error 2 is 'RAM Error'.
I suspect that the issue is that you lost the RAM contents for the
Calibration RAM. Have you tried to calibrate the unit? Have you checked
the power supplies?
The alternative is once the lead slipped off, it 'connected' to something
else and took out something. Was it the + or - lead?
Sounds like you need to go the service manual and start with the trouble
shooting section, probably Service Group E, and go from there.
Good luck.
Joe
From: hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com>
[mailto:hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com>] On Behalf Of xyloeye
Sent: Thursday, January 17, 2013 2:06 PM
To: hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com>
Subject: [hp_agilent_equipment] HP 3468 DMM battery change
I'm having some trouble with a battery change in a 3468 DMM. You would think
I could handle that without incident! I kept 3 volts on the terminals while
soldering in the new battery but one of the leads slipped off and there went
the calibration. No problem - I can calibrate it again or so I thought. The
display flashed "error 1" (ram error)and then went blank. It's been blank
ever since despite all the resetting procedures I've tried. Could corrupt
ram cause this? Or is could I have somehow damaged the controller? Any
thoughts would be appreciated.
|
Yeah, I disconnected the battery overnight and shorted the RAM chip Vcc to gnd to clear any leftover capcitance, etc. That had no effect. I'm kind of thinking maybe something was on the verge of failure and I pushed it over the edge. Problem is, even if I narrow it down to a component, all of the chips are unobtainable now.
Thanks again for your help Jeff.
Ken
toggle quoted message
Show quoted text
--- In hp_agilent_equipment@..., Jeff Machesky wrote:
You may need to disconnect the battery again to allow the RAM to "zero"
out. Well at least not be in it's present state.
Just a thought,
Jeff
On 1/17/2013 5:16 PM, xyloeye wrote:
Thanks for your reply. You're right, error 1 is calibration RAM. I
tried to calibrate it but since the display is dead, it's hard to do.
When the lead fell off I'm positive it didn't touch anything else. I
just can't figure out how disconnecting the battery would cause a dead
display.
Ken
--- In hp_agilent_equipment@...
, "J. L. Trantham" wrote:
I tried to remove and read the contents of the ROM on my 3478A. In the
process, I apparently shorted the 5 V line to ground, which somehow
killed
the contents of the CALRAM. In any event, there was a message about
Calibration. I then replaced the battery and went through the recalibration
steps and all was well.
According to the manual for the 3468A, Error 1 is 'Calibration RAM Error'.
Error 2 is 'RAM Error'.
I suspect that the issue is that you lost the RAM contents for the
Calibration RAM. Have you tried to calibrate the unit? Have you checked
the power supplies?
The alternative is once the lead slipped off, it 'connected' to something
else and took out something. Was it the + or - lead?
Sounds like you need to go the service manual and start with the trouble
shooting section, probably Service Group E, and go from there.
Good luck.
Joe
From: hp_agilent_equipment@... [mailto:hp_agilent_equipment@... ] On Behalf Of xyloeye
Sent: Thursday, January 17, 2013 2:06 PM
To: hp_agilent_equipment@... Subject: [hp_agilent_equipment] HP 3468 DMM battery change
I'm having some trouble with a battery change in a 3468 DMM. You would think
I could handle that without incident! I kept 3 volts on the terminals while
soldering in the new battery but one of the leads slipped off and there went
the calibration. No problem - I can calibrate it again or so I thought. The
display flashed "error 1" (ram error)and then went blank. It's been blank
ever since despite all the resetting procedures I've tried. Could corrupt
ram cause this? Or is could I have somehow damaged the controller? Any
thoughts would be appreciated.
[Non-text portions of this message have been removed]
|
Did you check the power supply voltages?
Joe
toggle quoted message
Show quoted text
-----Original Message----- From: hp_agilent_equipment@... [mailto:hp_agilent_equipment@...] On Behalf Of xyloeye Sent: Friday, January 18, 2013 1:52 PM To: hp_agilent_equipment@... Subject: [hp_agilent_equipment] Re: HP 3468 DMM battery change Yeah, I disconnected the battery overnight and shorted the RAM chip Vcc to gnd to clear any leftover capcitance, etc. That had no effect. I'm kind of thinking maybe something was on the verge of failure and I pushed it over the edge. Problem is, even if I narrow it down to a component, all of the chips are unobtainable now. Thanks again for your help Jeff. Ken --- In hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com> , Jeff Machesky wrote:
You may need to disconnect the battery again to allow the RAM to "zero"
out. Well at least not be in it's present state.
Just a thought,
Jeff
On 1/17/2013 5:16 PM, xyloeye wrote:
Thanks for your reply. You're right, error 1 is calibration RAM. I
tried to calibrate it but since the display is dead, it's hard to do.
When the lead fell off I'm positive it didn't touch anything else. I
just can't figure out how disconnecting the battery would cause a dead
display.
Ken
--- In hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com> , "J. L. Trantham" wrote:
I tried to remove and read the contents of the ROM on my 3478A. In the
process, I apparently shorted the 5 V line to ground, which somehow
killed
the contents of the CALRAM. In any event, there was a message about
Calibration. I then replaced the battery and went through the recalibration
steps and all was well.
According to the manual for the 3468A, Error 1 is 'Calibration RAM Error'.
Error 2 is 'RAM Error'.
I suspect that the issue is that you lost the RAM contents for the
Calibration RAM. Have you tried to calibrate the unit? Have you
checked the power supplies?
The alternative is once the lead slipped off, it 'connected' to something
else and took out something. Was it the + or - lead?
Sounds like you need to go the service manual and start with the
trouble shooting section, probably Service Group E, and go from there.
Good luck.
Joe
From: hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
[mailto:hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com> ] On Behalf Of xyloeye
Sent: Thursday, January 17, 2013 2:06 PM
To: hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
Subject: [hp_agilent_equipment] HP 3468 DMM battery change
I'm having some trouble with a battery change in a 3468 DMM. You would think
I could handle that without incident! I kept 3 volts on the terminals while
soldering in the new battery but one of the leads slipped off and there went
the calibration. No problem - I can calibrate it again or so I thought. The
display flashed "error 1" (ram error)and then went blank. It's been blank
ever since despite all the resetting procedures I've tried. Could corrupt
ram cause this? Or is could I have somehow damaged the controller? Any
thoughts would be appreciated.
|
I finally had time to get back to it tonight. Joe mentioned power supply voltages. I had checked random points to make sure the power supply was running but I failed to check all the voltages at the service jumpers. When I did, all but the -15V rails were very low. I disconnected the jumpers one by one but nothing past them was dragging the voltages down. I thought I had it narrowed down to one of the temperature sense resistors. I was looking over the board with magnifiers when I spotted a small piece of solder shorting two pins of the main regulator (U701). I didn't see it before because it was hidden under the heat sink. Must have happened when I did the battery change.
So I'm up and running. All I have to do is calibrate it and I think it'll be good to go. So thanks, all of you who made suggestions. I broke the cardinal rule of checking all voltages first. I really appreciate your help.
Ken
toggle quoted message
Show quoted text
--- In hp_agilent_equipment@..., "J. L. Trantham" wrote:
Did you check the power supply voltages?
Joe
-----Original Message-----
From: hp_agilent_equipment@...
[mailto:hp_agilent_equipment@...] On Behalf Of xyloeye
Sent: Friday, January 18, 2013 1:52 PM
To: hp_agilent_equipment@...
Subject: [hp_agilent_equipment] Re: HP 3468 DMM battery change
Yeah, I disconnected the battery overnight and shorted the RAM chip Vcc to
gnd to clear any leftover capcitance, etc. That had no effect. I'm kind of
thinking maybe something was on the verge of failure and I pushed it over
the edge. Problem is, even if I narrow it down to a component, all of the
chips are unobtainable now.
Thanks again for your help Jeff.
Ken
--- In hp_agilent_equipment@...
, Jeff Machesky wrote:
You may need to disconnect the battery again to allow the RAM to "zero"
out. Well at least not be in it's present state.
Just a thought,
Jeff
On 1/17/2013 5:16 PM, xyloeye wrote:
Thanks for your reply. You're right, error 1 is calibration RAM. I
tried to calibrate it but since the display is dead, it's hard to do.
When the lead fell off I'm positive it didn't touch anything else. I
just can't figure out how disconnecting the battery would cause a dead
display.
Ken
--- In hp_agilent_equipment@...
, "J. L. Trantham" wrote:
I tried to remove and read the contents of the ROM on my 3478A. In the
process, I apparently shorted the 5 V line to ground, which somehow
killed
the contents of the CALRAM. In any event, there was a message about
Calibration. I then replaced the battery and went through the recalibration
steps and all was well.
According to the manual for the 3468A, Error 1 is 'Calibration RAM Error'.
Error 2 is 'RAM Error'.
I suspect that the issue is that you lost the RAM contents for the
Calibration RAM. Have you tried to calibrate the unit? Have you
checked
the power supplies?
The alternative is once the lead slipped off, it 'connected' to something
else and took out something. Was it the + or - lead?
Sounds like you need to go the service manual and start with the
trouble
shooting section, probably Service Group E, and go from there.
Good luck.
Joe
From: hp_agilent_equipment@...
[mailto:hp_agilent_equipment@...
] On Behalf Of xyloeye
Sent: Thursday, January 17, 2013 2:06 PM
To: hp_agilent_equipment@...
Subject: [hp_agilent_equipment] HP 3468 DMM battery change
I'm having some trouble with a battery change in a 3468 DMM. You would think
I could handle that without incident! I kept 3 volts on the terminals while
soldering in the new battery but one of the leads slipped off and there went
the calibration. No problem - I can calibrate it again or so I thought. The
display flashed "error 1" (ram error)and then went blank. It's been blank
ever since despite all the resetting procedures I've tried. Could corrupt
ram cause this? Or is could I have somehow damaged the controller? Any
thoughts would be appreciated.
[Non-text portions of this message have been removed]
|
Great to hear for both you and the meter. It's so easy to have that solder drop from time to time. Good thing is nothing serious happen with the meter.
Jeff
toggle quoted message
Show quoted text
On 1/19/2013 9:07 PM, xyloeye wrote:
I finally had time to get back to it tonight. Joe mentioned power supply voltages. I had checked random points to make sure the power supply was running but I failed to check all the voltages at the service jumpers. When I did, all but the -15V rails were very low. I disconnected the jumpers one by one but nothing past them was dragging the voltages down. I thought I had it narrowed down to one of the temperature sense resistors. I was looking over the board with magnifiers when I spotted a small piece of solder shorting two pins of the main regulator (U701). I didn't see it before because it was hidden under the heat sink. Must have happened when I did the battery change.
So I'm up and running. All I have to do is calibrate it and I think it'll be good to go. So thanks, all of you who made suggestions. I broke the cardinal rule of checking all voltages first. I really appreciate your help.
Ken
--- In hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com>, "J. L. Trantham" wrote:
Did you check the power supply voltages?
Joe
-----Original Message-----
From: hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
[mailto:hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com>] On Behalf Of xyloeye
Sent: Friday, January 18, 2013 1:52 PM
To: hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com>
Subject: [hp_agilent_equipment] Re: HP 3468 DMM battery change
Yeah, I disconnected the battery overnight and shorted the RAM chip Vcc to
gnd to clear any leftover capcitance, etc. That had no effect. I'm kind of
thinking maybe something was on the verge of failure and I pushed it over
the edge. Problem is, even if I narrow it down to a component, all of the
chips are unobtainable now.
Thanks again for your help Jeff.
Ken
--- In hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com>
, Jeff Machesky wrote:
You may need to disconnect the battery again to allow the RAM to
"zero"
out. Well at least not be in it's present state.
Just a thought,
Jeff
On 1/17/2013 5:16 PM, xyloeye wrote:
Thanks for your reply. You're right, error 1 is calibration RAM. I
tried to calibrate it but since the display is dead, it's hard
to do.
When the lead fell off I'm positive it didn't touch anything
else. I
just can't figure out how disconnecting the battery would cause
a dead
display.
Ken
--- In hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
, "J. L. Trantham" wrote:
I tried to remove and read the contents of the ROM on my
3478A. In the
process, I apparently shorted the 5 V line to ground, which
somehow
killed
the contents of the CALRAM. In any event, there was a message
about
Calibration. I then replaced the battery and went through the recalibration
steps and all was well.
According to the manual for the 3468A, Error 1 is 'Calibration
RAM
Error'.
Error 2 is 'RAM Error'.
I suspect that the issue is that you lost the RAM contents for the
Calibration RAM. Have you tried to calibrate the unit? Have you
checked
the power supplies?
The alternative is once the lead slipped off, it 'connected' to something
else and took out something. Was it the + or - lead?
Sounds like you need to go the service manual and start with the
trouble
shooting section, probably Service Group E, and go from there.
Good luck.
Joe
From: hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
[mailto:hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
] On Behalf Of xyloeye
Sent: Thursday, January 17, 2013 2:06 PM
To: hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
Subject: [hp_agilent_equipment] HP 3468 DMM battery change
I'm having some trouble with a battery change in a 3468 DMM. You would think
I could handle that without incident! I kept 3 volts on the terminals while
soldering in the new battery but one of the leads slipped off and there went
the calibration. No problem - I can calibrate it again or so I thought. The
display flashed "error 1" (ram error)and then went blank. It's
been
blank
ever since despite all the resetting procedures I've tried. Could corrupt
ram cause this? Or is could I have somehow damaged the
controller? Any
thoughts would be appreciated.
|
I love it when it's the simple things.
Joe
toggle quoted message
Show quoted text
-----Original Message----- From: hp_agilent_equipment@... [mailto:hp_agilent_equipment@...] On Behalf Of xyloeye Sent: Saturday, January 19, 2013 10:07 PM To: hp_agilent_equipment@... Subject: [hp_agilent_equipment] Re: HP 3468 DMM battery change I finally had time to get back to it tonight. Joe mentioned power supply voltages. I had checked random points to make sure the power supply was running but I failed to check all the voltages at the service jumpers. When I did, all but the -15V rails were very low. I disconnected the jumpers one by one but nothing past them was dragging the voltages down. I thought I had it narrowed down to one of the temperature sense resistors. I was looking over the board with magnifiers when I spotted a small piece of solder shorting two pins of the main regulator (U701). I didn't see it before because it was hidden under the heat sink. Must have happened when I did the battery change. So I'm up and running. All I have to do is calibrate it and I think it'll be good to go. So thanks, all of you who made suggestions. I broke the cardinal rule of checking all voltages first. I really appreciate your help. Ken --- In hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com> , "J. L. Trantham" wrote:
Did you check the power supply voltages?
Joe
-----Original Message-----
From: hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com> [mailto:hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com> ] On Behalf Of xyloeye Sent: Friday, January 18, 2013 1:52 PM
To: hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com> Subject: [hp_agilent_equipment] Re: HP 3468 DMM battery change
Yeah, I disconnected the battery overnight and shorted the RAM chip Vcc to
gnd to clear any leftover capcitance, etc. That had no effect. I'm kind of
thinking maybe something was on the verge of failure and I pushed it over
the edge. Problem is, even if I narrow it down to a component, all of the
chips are unobtainable now.
Thanks again for your help Jeff.
Ken
--- In hp_agilent_equipment@... <mailto:hp_agilent_equipment%40yahoogroups.com> , Jeff Machesky wrote:
You may need to disconnect the battery again to allow the RAM to "zero"
out. Well at least not be in it's present state.
Just a thought,
Jeff
On 1/17/2013 5:16 PM, xyloeye wrote:
Thanks for your reply. You're right, error 1 is calibration RAM. I
tried to calibrate it but since the display is dead, it's hard to do.
When the lead fell off I'm positive it didn't touch anything else. I
just can't figure out how disconnecting the battery would cause a dead
display.
Ken
--- In hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
, "J. L. Trantham" wrote:
I tried to remove and read the contents of the ROM on my 3478A. In
the process, I apparently shorted the 5 V line to ground, which somehow killed
the contents of the CALRAM. In any event, there was a message about
Calibration. I then replaced the battery and went through the recalibration
steps and all was well.
According to the manual for the 3468A, Error 1 is 'Calibration RAM Error'.
Error 2 is 'RAM Error'.
I suspect that the issue is that you lost the RAM contents for the
Calibration RAM. Have you tried to calibrate the unit? Have you
checked
the power supplies?
The alternative is once the lead slipped off, it 'connected' to something
else and took out something. Was it the + or - lead?
Sounds like you need to go the service manual and start with the
trouble
shooting section, probably Service Group E, and go from there.
Good luck.
Joe
From: hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
[mailto:hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
] On Behalf Of xyloeye
Sent: Thursday, January 17, 2013 2:06 PM
To: hp_agilent_equipment@...
<mailto:hp_agilent_equipment%40yahoogroups.com>
Subject: [hp_agilent_equipment] HP 3468 DMM battery change
I'm having some trouble with a battery change in a 3468 DMM. You would think
I could handle that without incident! I kept 3 volts on the terminals while
soldering in the new battery but one of the leads slipped off and there went
the calibration. No problem - I can calibrate it again or so I thought. The
display flashed "error 1" (ram error)and then went blank. It's been blank
ever since despite all the resetting procedures I've tried. Could corrupt
ram cause this? Or is could I have somehow damaged the controller?
Any thoughts would be appreciated.
|
Hi Ken,
I received your email about whether you had to calibrate every function in every range before the cal error would go away. I tried to respond, but got this error:
======================================================================
Sorry, we were unable to deliver your message to the following address.
<xyloeye@...>:
Remote host said: 554 delivery error: dd Sorry your message to xyloeye@... cannot be delivered. This account has been disabled or discontinued [#102]. - mta1006.mail.gq1.yahoo.com [BODY]
======================================================================
In any case, If it's like the 3478A and 3457A, I believe you must successfully go through the entire calibration before the error will be cleared.
Jay
toggle quoted message
Show quoted text
--- In hp_agilent_equipment@..., "xyloeye" wrote:
I finally had time to get back to it tonight. Joe mentioned power supply voltages. I had checked random points to make sure the power supply was running but I failed to check all the voltages at the service jumpers. When I did, all but the -15V rails were very low. I disconnected the jumpers one by one but nothing past them was dragging the voltages down. I thought I had it narrowed down to one of the temperature sense resistors. I was looking over the board with magnifiers when I spotted a small piece of solder shorting two pins of the main regulator (U701). I didn't see it before because it was hidden under the heat sink. Must have happened when I did the battery change.
So I'm up and running. All I have to do is calibrate it and I think it'll be good to go. So thanks, all of you who made suggestions. I broke the cardinal rule of checking all voltages first. I really appreciate your help.
Ken
|
