HP 8563A from eBay and ERR 334 "LO AMPL" : need urgent advice pls.. - Page 1
Forum section: electronics / repair

author: ytterligare
author_rank: Regular Contributor
timestamp: June 17, 2021, 03:29:20 am
content: Hello, I just pulled the trigger few minutes ago on a 8563A on eBay, which was sold as in "working condition", which conforted me in shelling out a quite big amount of money for my pocket.After a few moments I noticed that the pics in the AD was showing an error which I thoughts was something trivial, but according to the service manual it seems not like it :ERR 334 "LO AMPL"I then made a search on this board and noticed that another user ( "1Ghz" ) had the same error and fixed the problem by....replacing the YTO (YIG oscillator) !!Now, 1Ghz was reporting the SA as "not working, while the seller for my unit was reporting it as in "working condition"....I'm confused...and since I payed ( with overseas shipping and custom fees ) almost 3000 USD, I'm rather scared, since I'm really not skilled enough to troubleshoot or repair it.Can someone ( urgently ) advice please..?Thank you !!AndyP.S.: the comforting case described by the service manual "Error 334 may also be displayed if the front-panel LO OUTPUT is not terminated into 50 ohms" seems not to be the case as in the picture the LO output seems correctly terminated..

author: bob91343
author_rank: Super Contributor
timestamp: June 17, 2021, 06:07:01 am
content: It does appear that your next move would be to contact the seller and see what he is willing to do. If that doesn't satisfy you then the next step is to ask ebay for help in resolving the situation.Don't try to repair it until your complaint is resolved to your satisfaction.

author: ytterligare
author_rank: Regular Contributor
timestamp: June 17, 2021, 11:32:48 pm
content: Quote from: bob91343 on June 17, 2021, 06:07:01 amTnx Buddy, I already did contact the seller but he hasnt' responded yet after 21 hours.BTW the SA is still by the seller and I explicitly asked him not to ship it overseas ( USA -> IT ) until I get a satisfactory clarification from him.BTW, does anyone knows whether ERR 334 is thrown on saltuary and negligible occasions ( such as the non terminated LO OUTPUT ), or it is serious such as needing to force a replacement of the YIG oscillator ?TnxA.

author: Tony_G
author_rank: Super Contributor
timestamp: June 18, 2021, 12:09:35 am
content: Hey ytterligare,There are a couple of dozen posts on ERR 334 over onhttps://groups.io/g/HP-Agilent-Keysight-equipment/might be worth reading them.From my quick look, it seems like the consensus is that it is a YIG issue mostly, with only the 1st LO terminator as the other option. Also, that error seems to only appear if the sweep range covers the YIG issue frequency so you should make sure that the vendor shows you it doing a full sweep.I need to go turn on my 3563E and to calm my nerves nowTonyG

author: ytterligare
author_rank: Regular Contributor
timestamp: June 18, 2021, 01:39:25 pm
content: Quote from: Tony_G on June 18, 2021, 12:09:35 amHello Tony, tnx for the reply and tnx for the link...I immediately subscribed ;-)Well, after few hours the seller contacted me : he's just in charge of selling older hardware which is supposed to be functional, for a third party company, but he's not really familiar with this family of SA...he told me it was supplied as "fully functional", so I guess a traceback to the original supplier's going to star now ...He was a gentleman tho, and after apologizing he cancelled the order and refound me full, end of case.Now back in the market for a ( truly ) fully functional 26.5 Ghz 8563A, which, I get from you, is also good for soothing on the nerves..CiaoAndrea

author: Zenwizard
author_rank: Regular Contributor
timestamp: June 30, 2021, 09:03:38 pm
content: I would also check out the signal path on you tube. Shahriar mentions this quite a bit. It seems to be a YIG ageing issue. As the YIG's age the output falls off till the LO wont lock any more. From what I have seen repairing a YIG is not for the faint of heart and is a stopgap measure. I suspect the hour counter is high on the unit in question.