Agilent DSO9104A Scope stopped booting up. Advice On way forwards. - Page 1
Forum section: electronics / repair

author: magnetchief
author_rank: Contributor
timestamp: April 21, 2022, 07:46:56 pm
content: Hi, I have a nice 1GHz Infiniium Scope that's stopped working.It was fine earlier in the week, now its non functioning.Things I have tried.1. Powering on, the fans and control knobs spin and light up momentarily. Then nothing.2. Opened up the case to check the battery on the motherboard, a simple lithium cell. It read 3v, but replaced it anyway. No change.3. There is a series of fault finding leds inside of the case. When it fails to boot LEDs #1 & 2 remain illuminated in Sequence #2.From the attached guide 1 & 2 are fault type SEQ2: U497. I think this is an external fault as I read the troubleshooting guide inhttps://xdevs.com/doc/HP_Agilent_Keysight/54904-97014%20Infiniium%209000%20Series%20Oscilloscope%20Service%20Guide%20%5B128%5D.pdf4. I checked the various connectors and cables, they all look secure.Any thoughts before I ship this off ? Much appreciated.

author: magnetchief
author_rank: Contributor
timestamp: April 22, 2022, 03:05:10 pm
content: Photo showing led sequence.

author: free_electron
author_rank: Super Contributor
timestamp: April 22, 2022, 05:07:50 pm
content: check the power rails. 1.2 or 1.8 volt is missing. these are typically modules on the acquisition board. i doubt those die. most likely the input to those modules is missing. if i remember correctly there are surface mounted fuses on the board. check those.

author: magnetchief
author_rank: Contributor
timestamp: April 22, 2022, 05:18:39 pm
content: Many thanks, will investigate further.

author: magnetchief
author_rank: Contributor
timestamp: April 26, 2022, 01:43:05 pm
content: Checked what I could within my ability.The voltages from the accusation board looks fine, as far as I can tell.I could not find any onboard fuses except one deep in the main power supply.I'm thinking I'm going to have to bite the bullet and send it back to Keysight for a repair. $5300 qute.

author: salvagedcircuitry
author_rank: Regular Contributor
timestamp: May 15, 2022, 01:02:01 am
content: Did you have any luck troubleshooting and repairing your DSO9104 oscilloscope?It seems your 1.2v rail is problematic. Were you able to check the second sequencer? Maybe some type of failure between different stages of dc-dc conversion?Thanks

author: parawizard
author_rank: Regular Contributor
timestamp: January 07, 2025, 07:53:01 pm
content: Quote from: magnetchief on April 26, 2022, 01:43:05 pmDid they tell you what the issue is? I am considering buying one with a similar issue.

author: magnetchief
author_rank: Contributor
timestamp: January 07, 2025, 08:52:57 pm
content: I'm afraid not.It's just 'Repair by replacement'

author: parawizard
author_rank: Regular Contributor
timestamp: January 08, 2025, 08:39:37 am
content: Got it. Thanks for the reply. If I end up getting the unit and fixing it I will post here what I found.

author: parawizard
author_rank: Regular Contributor
timestamp: January 18, 2025, 12:28:23 am
content: Quote from: magnetchief on January 07, 2025, 08:52:57 pmDid you replace the whole unit or did you do a part replacement? If a part replacement what part?Thanks