Author Topic: AGILENT 34401A  (Read 3503 times)

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Offline EE-digger

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Re: AGILENT 34401A
« Reply #25 on: March 06, 2019, 04:06:17 am »
I had a VERY similar problem on a 33120A function generator.  I have no idea if the two have any similarity but your symptoms give me deja-vu.

On the 33120A, a small reset chip was not coming up to full logic high output.  It was stuck midway up, hence resets were not clean for both the main and display processors.

I don't know if the 34401A actually has a separate display processor or not.
 

Offline wictor

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Re: AGILENT 34401A
« Reply #26 on: March 06, 2019, 11:15:29 am »
There is separate processor in front panel. It's getting all display data from main board cpu. If there is no data arriving to front panel, there is nothing displayed.
 

Offline coromonadalix

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Re: AGILENT 34401A
« Reply #27 on: March 06, 2019, 11:26:19 am »
the best course would be to have another display to do some tests,  or a logic sniffer  ...... to be sure

I wont argue with all voltages, but do a recheck, theres many of them

Its an old meter,  in mine i have done the recapping  to be sure, they where all working before, but the tantalums where ginving me frills, in one they where slightly brown"ish"
 

Offline SpencerTC

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Re: AGILENT 34401A
« Reply #28 on: March 06, 2019, 04:34:52 pm »
Have you tried to get any response through GPIB (or other external communications)?
 

Offline coromonadalix

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Re: AGILENT 34401A
« Reply #29 on: March 06, 2019, 05:53:45 pm »
With no screen   how can we know the gpib adress ?  unless you see it briefly ???
 

Offline HighVoltage

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Re: AGILENT 34401A
« Reply #30 on: March 06, 2019, 06:21:33 pm »
With no screen   how can we know the gpib adress ?  unless you see it briefly ???
You just try them all, there are not too many possibilities.
There are 3 kinds of people in this world, those who can count and those who can not.
 

Offline picburner

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Re: AGILENT 34401A
« Reply #31 on: March 06, 2019, 06:56:13 pm »
With NI MAX you can do an automatic scan and it tells you which instruments are connected and their address.
I think you can do the same with Agilent's software.
 

Offline HighVoltage

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Re: AGILENT 34401A
« Reply #32 on: March 06, 2019, 07:56:21 pm »
Yes, the Keysight software scans automatically for what is hooked up to any of the GPIB ports.
There are 3 kinds of people in this world, those who can count and those who can not.
 

Offline lionelkjh

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Re: AGILENT 34401A
« Reply #33 on: March 10, 2019, 05:31:47 pm »
Good evening; I made no attempt with the GPIB (because I do not have this big connector, nor software, nor interface!): in summary; I'm a little lost! I specify that this version and 2008 it is more recent than the first models released in the 90s. How to ??? :palm: :palm: :palm:
 

Offline SpencerTC

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Re: AGILENT 34401A
« Reply #34 on: March 11, 2019, 02:33:08 am »
Well, the first thing I generally check with nonfunctional equipment is the easiest things...external communication (GPIB, serial), ensuring voltages are correct (that 3.3VDC test point is close to 3.3V, same with any other voltages noted on silkscreen/in service manual), unseat and reseat any socketed IC's, see if there are any unpopulated {or populated} footprints that could be looked at (ex. JTAG, serial), sniff around with logic analyzer.

I own a 34401A, although I've never had an issue with it and have not had a reason to become familar with the troubleshooting process of it. If  you happen to have a second instrument that you can compare voltages, signals, and responses to, then it can make the whole process much easier/quicker.

Try what you can and let us know what you find and I'm sure some more people will try to help (either I or some of the much more knowledgeable people on this site)

Good luck!
 

Offline coromonadalix

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Re: AGILENT 34401A
« Reply #35 on: March 11, 2019, 02:47:14 am »
just had a small problem with my second  34401  the white display connector would not "get up"  or stuck at "pressed position" not closing on the flex cable center pins  when i pushed it to do a verification  ???

Worth to check



@Lionelkjh  you can surely build the project  ar488 usb to gpib adapter for almost nothing, you can communicate thru serial console,   or even try with the rs232 if there is somthing going out of the meter
https://www.eevblog.com/forum/projects/ar488-arduino-based-gpib-adapter/



But for the rs232 normally you set the communication type with the meter menu .....  the talkback (you only read / see the meter readings / no interaction is possible, is done at adress 37 if i recall
« Last Edit: March 12, 2019, 01:40:28 am by coromonadalix »
 


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