- Flakey Molex(?) connectors - 5 Updates
- DeOxit as a corrosion inhibitor - 3 Updates
| legg <legg@nospam.magma.ca>: Jun 17 04:20PM -0400 On Sat, 15 Jun 2019 16:09:17 -0400, Bob Engelhardt >Bob >BTW - I fixed the tool by removing the contacts from the shell and >soldering them to the pins on the board. If they're tin plated, they are not good for small signals. The contact surfaces can usually be restored by simply pulling and reinserting the connector a few times. Square pins can be brushed clean. The problem will reoccur. It can be agravated by mixing tin with gold flash (pins vs receptacles. Sometimes the gold flash in the receplacles is local and hard to identify. Depending on humidity and temperature levels, the tin/tin contacts are good for between 6 and 10 years, between cleanings. RL |
| makolber@yahoo.com: Jun 18 07:34AM -0700 > Depending on humidity and temperature levels, the tin/tin contacts are > good for between 6 and 10 years, between cleanings. > RL google "fretting" corrosion. can be insidious to troubleshoot mark |
| John Robertson <spam@flippers.com>: Jun 18 07:51AM -0700 > google "fretting" corrosion. > can be insidious to troubleshoot > mark Thanks for that info - I went to one link: https://www.windpowerengineering.com/mechanical/bolts-and-bolting/how-to-recognize-fretting-corrosion-and-what-to-do-about-it/ where they talk about fretting corrosion in wind turbines. Even when there is lubrication fretting corrosion occurs, but it is more benign with lubrication as opposed to no lubrication. So I suggest folks look at something like Dow Corning #4 dielectric grease for connectors that experience any vibration to increase the MTBF of the connection(s). I know DC#4 helps my games run longer between service. Others swear by De-Oxit, but the resulting contact protection is probably similar. John :-#)# -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out." |
| legg <legg@nospam.magma.ca>: Jun 18 11:04AM -0400 On Tue, 18 Jun 2019 07:51:07 -0700, John Robertson <spam@flippers.com> wrote: >Others swear by De-Oxit, but the resulting contact protection is >probably similar. >John :-#)# That's a mechanical failure in iron-bearing materials. The small signal electrical contact failure is straight oxidation of tin. RL |
| John Robertson <spam@flippers.com>: Jun 18 08:38AM -0700 On 2019/06/18 8:04 a.m., legg wrote: > The small signal electrical contact failure is straight oxidation of > tin. > RL I dunno, I've seen a lot of contact failure over the years and fretting would explain some of what I am seeing. And a product like DC#4 (now called Molykote) helps prevent failure by providing both mechanical (friction reduction) and electrical protection: https://www.dupont.com/content/dam/Dupont2.0/Products/transportation/Literature/TDS/10-1187-01.pdf John :-#)# |
| Jeff Liebermann <jeffl@cruzio.com>: Jun 17 09:52PM -0700 "How corrosion inhibitors protect metal: synthesis in the lab and testing" <https://www.youtube.com/watch?v=VpRrP3sqQLw> (23:01) This video isn't really about DeOxit but does offer a good clue as to the formulation and how it works. The video does a better job of explaining what's happening than I could, so I won't repeat much of its contents. He mentions that his inspiration came from this patent: "Corrosion inhibited lubricant composition" <https://patents.google.com/patent/US4193882> Note that Camolin Red, the predecessor of DeOxit, shows 5% oleic acid and 95% "volatile hydrocarbons and propellant". I had been assuming that the hydrocarbons were just mineral oil or something similar. Apparently not. I'm also assuming that the steel corrosion protection that DeOxit shows in the video, also applies to copper wire and silver plated contacts. -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
| Jeff Urban <jurb6006@gmail.com>: Jun 17 11:26PM -0700 It's like 2:00 AM and I can't play videos right now because every time I do they come up with a big BOOM and I am waiting for it to happen and the others come and say "Did you blow off a gun in the house ?". One time I plugged in a preamp that had DC on the output and when I switched to it the thud was like, you would think like maybe a big bookshelf got tipped on the floor or some shit. Anyway, what makes Deoxit Deoxit is the reducer. It is a very small part of the contents but the part that really does the work. I do not know which component it is. It actually takes the oxygen out of the metal. Now if you can get that stuff to forever be on the metal I imagine it would be really protected. Some sort of non-volatile grease, but I don't know if it is oil soluble. If I were so inclined I would do a little research and find out exactly how a reducer works, what they are, their properties and all that but rally, I have enough going on. There has to be someone around here who knows more. If not maybe we have to go find somewhere else. Yeah I am interested but I am not willing to spend a week on it. |
| gregz <zekor@comcast.net>: Jun 18 08:05AM > rally, I have enough going on. There has to be someone around here who > knows more. If not maybe we have to go find somewhere else. > Yeah I am interested but I am not willing to spend a week on it. Cramolin Red did not first come in spray. Just like 100% Deoxit D100. I'll look at that video, but can't on this old tablet. Greg |
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