[time-nuts] OT: Question on dead HP34401

paul swed paulswedb at gmail.com
Tue Dec 11 20:40:39 UTC 2012


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.griffiths at 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 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 trapping the problem difficult. One strange thing that I
>> see
>> is that there is a 7 kHz repeating reset signal on the reset line that
>> does
>> NOT come from the voltage regulator's reset output but must be generated
>> by
>> the processor or an ASIC. Anyone having an idea to that?
>>
>> Best regards and TIA for your answers
>>
>> Ulrich Bangert
>> www.ulrich-bangert.de
>> Ortholzer Weg 1
>> 27243 Gross Ippener
>>
>>
>> ______________________________**_________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/**
>> mailman/listinfo/time-nuts<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts>
>> and follow the instructions there.
>>
>>
>>
> Which reset?
> Assuming the circuit is the same as mine (Setember 1991 -October 1991)
> The Floating logic reset, the Earth referenced resets: 8051 reset
> (generated by absence of crossguard comms) or the 9914 reset?
> The only ASICS are U101(analog switch array), U102(resistor array) and
> U501 (gate array), none of which generate a reset.
>
> Bruce
>
> Bruce
>
> ______________________________**_________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/**
> mailman/listinfo/time-nuts<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts>
> and follow the instructions there.
>


More information about the time-nuts mailing list