- Removing Large Electrolytics - 9 Updates
| Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net>: Aug 24 01:18PM -0400 >> Some styles of electrolytics may be particularly difficult to remove gracefully. The ground tabs of the FP style were often twisted for mechanical stability before soldering. And sometimes, the pins were folded over before soldering. > If enough solder is removed, twisted tabs can then be twisted back. A bit of remaining solder can be ignored, it lacks enough strength to get in the way. Folded over legs can be pushed up with a soldering iron before attempting removal. > NT This might be a good use for Chip Quik--it's a bismuth-based solder that drops the liquidus point of a joint low enough that gentle use of a heat gun will melt it. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com |
| Cursitor Doom <curd@notformail.com>: Aug 24 11:33PM On Fri, 24 Aug 2018 13:18:02 -0400, Phil Hobbs wrote: > This might be a good use for Chip Quik--it's a bismuth-based solder that > drops the liquidus point of a joint low enough that gentle use of a heat > gun will melt it. I had to use one of these so-called multi-tools to slice through the pins. There was about 2mm of clearance between the bottom of the caps and the PCB. This is one of those cutters that vibrates from side to side at high speed and the blade had *just* enough reach to cut through the most inaccessible pins. Double checking after removal confirmed they had all definitely failed (3 out of 6 altogether). -- This message may be freely reproduced without limit or charge only via the Usenet protocol. Reproduction in whole or part through other protocols, whether for profit or not, is conditional upon a charge of GBP10.00 per reproduction. Publication in this manner via non-Usenet protocols constitutes acceptance of this condition. |
| Cursitor Doom <curd@notformail.com>: Aug 24 11:42PM I had 3 faulty electrolytics; all 30V/5500uF. In my spares bin I found 6 NOS (new old stock) electros of values 35V/3300uF which when stacked 2 high and wired in parallel occupy - fortunately - the same footprint as the ones that failed. These spares, though unused, are probably 40 years old. Will they need re- forming gradually over 24hrs before installing? -- This message may be freely reproduced without limit or charge only via the Usenet protocol. Reproduction in whole or part through other protocols, whether for profit or not, is conditional upon a charge of GBP10.00 per reproduction. Publication in this manner via non-Usenet protocols constitutes acceptance of this condition. |
| tabbypurr@gmail.com: Aug 24 07:06PM -0700 On Saturday, 25 August 2018 00:42:23 UTC+1, Cursitor Doom wrote: > the ones that failed. > These spares, though unused, are probably 40 years old. Will they need re- > forming gradually over 24hrs before installing? I'd get newer ones if possible. At that age they'll be dead or near to it. In apps where high ESR is acceptable they last better, but still 40 is 80 human years for lytics. NT |
| Ralph Mowery <rmowery28146@earthlink.net>: Aug 24 10:45PM -0400 In article <plpekd$ka7$1@dont-email.me>, pcdhSpamMeSenseless@electrooptical.net says... > This might be a good use for Chip Quik--it's a bismuth-based solder that > drops the liquidus point of a joint low enough that gentle use of a heat > gun will melt it. Just make sure you get the type that is made to help remove solder. They make all kinds of solder type products. Some are just tin/lead and will not help in removal. From what little I have looked at it, the removal type is very expensive . |
| John Robertson <spam@flippers.com>: Aug 24 10:04PM -0700 On 2018/08/22 2:36 PM, Ron D. wrote: > You can also add a solder removal alloy form Chip-Quik. > You can break off the tabs sometimes. You can cut the can sometimes. I'd use these methods at last resort. > Solder with a low temperature allow after removing most of the solder and suck out is my best suggestion. I too like the idea of using a small amount of Chip-Qick after first removing as much solder as possible. This may make the solder bond so weak that it will break out with very little force. If not, then dig out a heat gun and secure the board - heating the area and pull on the capacitor at the same time, I've done that by tying a weight to the item to remove and let gravity do the work while I fart around with the heat gun, etc. 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." |
| Fox's Mercantile <jdangus@att.net>: Aug 25 12:35AM -0500 On 8/24/18 6:42 PM, Cursitor Doom wrote: > the ones that failed. > These spares, though unused, are probably 40 years old. Will they need re- > forming gradually over 24hrs before installing? Reforming is a fool's game. They either work to being with or they're bad. That size isn't cheap, but if you buy new ones, that's the end of your repair. <https://www.mouser.com/ProductDetail/Vishay-Sprague/TVA1229?qs=%2fha2pyFadujX3auk1NrQ%2fV7hXwNYjanuW1qcIa3mLSA%3d> -- "I am a river to my people." Jeff-1.0 WA6FWi http:foxsmercantile.com |
| Gunther Heiko Hagen <guntherxxx@quantserve.de>: Aug 25 10:43AM On Sat, 25 Aug 2018 00:35:34 -0500, Fox's Mercantile wrote: > Reforming is a fool's game. Throwing away is a fool's game. https://www.youtube.com/watch?v=nat1YYNMW5A |
| Cursitor Doom <curd@notformail.com>: Aug 25 01:32PM On Fri, 24 Aug 2018 19:06:43 -0700, tabbypurr wrote: > I'd get newer ones if possible. At that age they'll be dead or near to > it. In apps where high ESR is acceptable they last better, but still 40 > is 80 human years for lytics. I've always been of the view that it's excessive heat over long periods of operation that eventually kills 'lytics. I don't see how them being in store, albeit for many decades, could render them useless. But we shall see! I'm currently reforming the NOS ones I have and will report back on the results in due course. Fortunately I'm not doing this for any customer; I'm only a hobbyist working on my own stuff, so can easily afford to be proven wrong in this if such should turn out to be the case. ;-) -- This message may be freely reproduced without limit or charge only via the Usenet protocol. Reproduction in whole or part through other protocols, whether for profit or not, is conditional upon a charge of GBP10.00 per reproduction. Publication in this manner via non-Usenet protocols constitutes acceptance of this condition. |
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