Agilent / HP 54845a 1.5 GHz scope  Trigger self-test failures  - Page 1
Forum section: electronics / repair

author: rickells
author_rank: Regular Contributor
timestamp: April 16, 2019, 01:12:07 pm
content: hi,My Agilent 54845a has Trigger self-test "Failed" for all 3 of the detailed Trigger tests; on all 4 channels.The scope does power On & can measure the Sq. wave signal from the Aux Out, & other signals Ok, (with knobs twiddled manually).It passes all of the other self-tests, .... just Not any of the 3 Trigger tests.1) -- How is this Trigger problem fixed ??I have cleaned the ADC's, examined the Acq board for solder/IC placement issues, but see none.Over the years there have been a few individuals who had the same issue (JayW, JWalling, TRN) & perhaps others, but details seem not to be found...TRN seems to have started to examine a few IC voltages & signals ...-somewhat difficult with no schematics in the service manual.What is the problem area, or solution ??thank you,rPrevious references to Agilent / HP 54845a & 54831b or 54832b Trigger problem:https://www.eevblog.com/forum/repair/sometimes-knowing-what-something-means-is-half-the-battle-agilent-54831b-error/msg1008382/#msg1008382https://www.eevblog.com/forum/testgear/agilent-54845a-failing-all-trigger-self-tests/https://www.eevblog.com/forum/testgear/agilent-54835a-scope-(4-channel-1ghz-4gss)-repair-uphack/https://www.eevblog.com/forum/repair/agilenthp-54845a/msg1267378/#msg1267378https://www.eevblog.com/forum/testgear/agilent-54831d-modernising/https://community.keysight.com/thread/6575https://community.keysight.com/search.jspa?q=54845ahttps://community.keysight.com/message/15068http://www.dasarodesigns.com/projects/fixing-an-hp-agilent-54845a-infinium-oscilloscope/https://wonghoi.humgar.com/Hobby.htm

author: rickells
author_rank: Regular Contributor
timestamp: April 20, 2019, 05:52:57 am
content: ?? Does any one have a Spare ADC plastic socket for the 54845 with pogo pins ??I think I have located one problem:I have one damaged plastic ADC socket, with missing Gold coloured pogo pins (I have the 4+2 screws removed, & the 2 metal sandwich parts removed & the white ceramic part removed).So, I need to get a socket or try to repair the existing socket that has missing pins & springs.How does one R&R the Pogo pin socket ?It looks like there are some small steel guide pins holding the socket onto the ADC PCB?>>>>Example showing the ADC chip removed & the plastic pogo pin socket removed from the PCB.>> How does one remove the plastic socket at that level ??see the photos #9 & #10 in the EEVBlog July 8, 2017:https://www.eevblog.com/forum/testgear/agilent-54835a-scope-(4-channel-1ghz-4gss)-repair-uphack/Does any one have a spare 54845a ADC socket !thank you,

author: Tony_G
author_rank: Super Contributor
timestamp: April 20, 2019, 02:30:19 pm
content: Sorry I couldn't be of more help in your quest to fix this. Please followup on here with this fix (if there is one) to the working sockets w.r.t the trigger level as finding a root cause for this seems to be something that hasn't either been found or shared (my one just had vertical and FISO errors which socket cleaning fixed).Good luck and look forward to hearing more.TonyG