Gunk buildup on old CRO? - Page 1
Forum section: electronics / beginners

author: Gabriel
author_rank: Regular Contributor
timestamp: October 27, 2017, 09:18:56 am
content: Hi All,I have this strange build up of gunk on a old CRO that I am currently repairing. I was wandering if anyone knew what it is, how to get rid of it (if I should even get rid of it)Anyone had such a problem before?Thanks in Advance,Gabriel

author: Coceth
author_rank: Contributor
timestamp: October 27, 2017, 10:21:48 am
content: Is it inhibiting the performance of the scope? If yes, then you should get rid of it.What kind of gunk are you dealing with? Can it be resolved with some isopropyl alcohol and a toothbrush? Maybe a spray of DeoxIT?

author: danadak
author_rank: Super Contributor
timestamp: October 27, 2017, 10:49:23 am
content: Tek method, attached.Regards, Dana.

author: tggzzz
author_rank: Super Contributor
timestamp: October 27, 2017, 11:04:23 am
content: Do you think it might be useful if the OP gave us a clue about what the scope is, where the gunk is, some description of colour, texture, thickness, and even a photo or two?

author: james_s
author_rank: Super Contributor
timestamp: October 27, 2017, 08:44:48 pm
content: The only thing I routinely see in old equipment that I would describe as "gunk" is nicotine sludge from equipment being used around smokers. Gross sticky stuff, stinks too.

author: Gabriel
author_rank: Regular Contributor
timestamp: October 28, 2017, 12:41:14 am
content: Quote from: tggzzz on October 27, 2017, 11:04:23 amYes I should of posted a photo or two, so here is 6 of themIt is yellow ish and has a rough texture it feels like they are small crystals.I know it is not nicotine as it is odourless and I don't now of it being around any smokers (but who knows). BTW it is a BWD 521Quote from: danadak on October 27, 2017, 10:49:23 amThank you for that Dana! What a gem! I don't know if I am brave enough to to just spray the whole thing with water but if worst comes to worst I might be doing that!Also any ideas on the best way to get rid of corrosion of BNC connectors? See photo attached, just some fine sandpaper?Thank you all for the help!

author: Gyro
author_rank: Super Contributor
timestamp: October 28, 2017, 08:55:30 am
content: That's corrosion from damp storage - the rusted screws are another big clue.You may be able to dust some of it off with a dry cloth [EDIT:Be careful in case the metalwork is Cadmium plated rather than just passivated]. I suggest putting it in a dry place for a reasonable period of time before trying to power it up.More water is definitely not what it needs.EDIT: Don't use sandpaper on the BNC connectors, you'll take off the silver plating. Try metal polish or a Silver cleaning cloth. Worst case, replace them.

author: SeanB
author_rank: Super Contributor
timestamp: October 28, 2017, 09:26:52 am
content: Robrenz on the forum had some really good guides on cleaning those BNC connectors on the forum.https://www.eevblog.com/forum/testgear/tek-7603-scope-w-7a18-amp-7b53a-timebase-restoration/msg172523/#msg172523https://www.eevblog.com/forum/testgear/hp-3410a-ac-microvoltmeter-restoration/msg433974/#msg433974Worth a look.