Agilent 34970A DAQ Self-Test Error 606 (Rundown gain out of range) - Page 1
Forum section: electronics / repair

author: mbendzick
author_rank: Newbie
timestamp: October 28, 2014, 10:24:33 pm
content: My office has a 34970A that fails self-test with error 606, Rundown gain out of range:"This test checks the nominal gain between the integrating ADC and the A1U205 on-chip ADC. The nominal gain is check to ±10% tolerance."The same 606 could be reported on a 34401A (the guts of which make up the core of the 34970A as I understand it):"This test checks the nominal gain between the integrating ADC and the U500 onchip ADC. The nominal gain is checked to ±10% tolerance."Anyone have ideas on how fixable this might be? What would this kind of failure show up as in measurements?

author: PTR_1275
author_rank: Frequent Contributor
timestamp: May 01, 2015, 10:24:32 am
content: Did you have any luck with this one?? I have been seeing a few 34970 coming up for sale with the same error. Not sure if it is worth buying them or not.

author: free_electron
author_rank: Super Contributor
timestamp: May 05, 2015, 11:10:05 pm
content: Rundown gain is typically a prblem in the current switching hybrid. 150$ a pop ...

author: mbendzick
author_rank: Newbie
timestamp: May 21, 2015, 03:59:26 pm
content: free_electron - please help me avoid the curse of the Wisdom of the Ancients (https://xkcd.com/979/) by offering me a little more information...Could you clarify which component on which board is the "current switching hybrid" ? The service guide for the 34970A has schematics and is athttps://www.keysight.com/main/gated.jspx?lb=1&gatedId=258467&cc=US&lc=eng&parentContId=1000001313:epsg:pro&parentContType=pt&parentNid=-33261.536881544&fileType=VIEWABLE.Based on your replies athttps://www.eevblog.com/forum/testgear/got-myself-an-agilent-34401a-with-a-label-%27not-working%27-on-it/, is it the "1NB4-5035" "CUST R NET PKG" loaded at U102?

author: mbendzick
author_rank: Newbie
timestamp: June 10, 2015, 05:01:18 pm
content: Are there places to order the hybrid at places besides Keysight's' find-a-part atwww.keysight.com/my/faces/fapHomePage.jspx?

author: ItIsJustMe
author_rank: Newbie
timestamp: October 03, 2019, 01:12:27 pm
content: Just fixed one 34970A with 606 self-test error by replacing P100 ribbon cable.Google service note 34970A-14C for more information.

author: shaohu.tang
author_rank: Contributor
timestamp: October 12, 2021, 11:22:23 am
content: I have repaired a 606 error failure of an Agilent 34401 multimeter. After replacing u420 and u402, it is ok.

author: shaohu.tang
author_rank: Contributor
timestamp: October 13, 2021, 09:46:47 am
content: Picture before repair。

author: shaohu.tang
author_rank: Contributor
timestamp: October 13, 2021, 09:56:32 am
content: Picture after repair 。

author: HighVoltage
author_rank: Super Contributor
timestamp: October 13, 2021, 10:52:13 am
content: What you repaired seems to be a 34401A and not a 34970A

author: shaohu.tang
author_rank: Contributor
timestamp: October 13, 2021, 11:03:59 am
content: Yes, it is 34401A. Others say it has many parts the same as 34970A.

author: voltsandjolts
author_rank: Unknown
timestamp: October 13, 2021, 11:22:36 am
content: Quote from: shaohu.tang on October 13, 2021, 09:56:32 amCan you confirm you replaced two ICs, AD711 and OP27 ?As seen here in the 34970A:

author: shaohu.tang
author_rank: Contributor
timestamp: October 13, 2021, 11:52:00 am
content: Quote from: voltsandjolts on October 13, 2021, 11:22:36 amyes .