measurement
Betreff: Re: [time-nuts] OT: Question on dead HP34401
So we are on the same page
You tie the reset through a 1 K r to vcc and you still see
the reset signal? And you do not see the 7 Khz coming from
the switching regulator?? Thanks
On Mon, Dec 17, 2012 at 2:57 AM, Ulrich Bangert
df
: Re: [time-nuts] OT: Question on dead HP34401
It only resets the earth referenced micro (8051) on power up and
when pulses on the optocoupler output arent present. There is no
other connection to the reset pin of this micro.
The floating logic is reset by the LM2925 5V
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Von: time-nuts-boun...@febo.com
[mailto:time-nuts-boun...@febo.com] Im Auftrag von Bruce Griffiths
Gesendet: Dienstag, 11. Dezember 2012 22:46
An: Discussion of precise time and frequency measurement
Betreff: Re: [time-nuts] OT: Question on dead HP34401
It only
-
Von: time-nuts-boun...@febo.com
[mailto:time-nuts-boun...@febo.com] Im Auftrag von Bruce Griffiths
Gesendet: Dienstag, 11. Dezember 2012 22:46
An: Discussion of precise time and frequency measurement
Betreff: Re: [time-nuts] OT: Question on dead HP34401
It only resets the earth
Gentlemen,
I own a dead HP34401. On switching it on the display stays dark. It will
however react on pressing the SHIFT key.
By changing pcbs against a working one the display board has shown to be ok.
There must be a problem with the main board. Without knowing whats inside
the ASICs make
Ulrich,
Yes indeed modern stuff is tough. I believe what you are seeing is a dead
man timer. The system is not booting correctly, times out and resets and
the process keeps going.
Typically a good place to look is at the interrupt lines to see what is
triggering the behavior.
If neither of these
Ulrich Bangert wrote:
Gentlemen,
I own a dead HP34401. On switching it on the display stays dark. It will
however react on pressing the SHIFT key.
By changing pcbs against a working one the display board has shown to be ok.
There must be a problem with the main board. Without knowing whats
Two comments the manuals available on agilent
What on earth is a crossguard?
On Tue, Dec 11, 2012 at 3:16 PM, Bruce Griffiths bruce.griffi...@xtra.co.nz
wrote:
Ulrich Bangert wrote:
Gentlemen,
I own a dead HP34401. On switching it on the display stays dark. It will
however react on
paul swed wrote:
Two comments the manuals available on agilent
What on earth is a crossguard?
Crossguard comms (Agilents term) refers to the optoisolators used for
serial communication between the floating and earth referenced logic
sections.
Bruce
At 21:40 11/12/2012, you wrote:
Two comments the manuals available on agilent
What on earth is a crossguard?
Data exchange between a floating, guarded circuit and a ground referenced one?
Marco IK1ODO
___
time-nuts mailing list --
OK but why would it tie to the reset line?
On Tue, Dec 11, 2012 at 3:48 PM, Marco IK1ODO -2 ik1...@spin-it.com wrote:
At 21:40 11/12/2012, you wrote:
Two comments the manuals available on agilent
What on earth is a crossguard?
Data exchange between a floating, guarded circuit and a
Long shot remedy : There is a front pannel push button sequence to turn off/on
the display.
--- On Tue, 12/11/12, Ulrich Bangert df...@ulrich-bangert.de wrote:
From: Ulrich Bangert df...@ulrich-bangert.de
Subject: [time-nuts] OT: Question on dead HP34401
To: Time nuts time-nuts@febo.com
Date
It only resets the earth referenced micro (8051) on power up and when
pulses on the optocoupler output arent present.
There is no other connection to the reset pin of this micro.
The floating logic is reset by the LM2925 5V regulator reset output.
There is no connection to this reset line aprt
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