dating electrolytic capacitors -how? - Page 1
Forum section: electronics / repair

author: jaunty
author_rank: Regular Contributor
timestamp: March 04, 2018, 09:37:25 pm
content: so ...i'm constantly working on my own gear in my recording studio - a lot of it is second hand and much of it has rework done on it - one problem always seems to come up - determining the general vintage of electrolytic caps - although yes - there can be clues like soldering done - often it is difficult if not impossible for me to tell the age of a replacement (or original capacitor) - I couldnt' really find much about this on google ... are there any magic recipes for determining the age of a cap like date codes etc (not that i can tell - and it seems to vary by manufacturer from what i can tell as well)

author: Shock
author_rank: Super Contributor
timestamp: March 04, 2018, 10:22:36 pm
content: Date codes, size, series, age of equipment.Look at datasheets or google how to read the date codes.If the caps are a crap brand or series or known/tested defective the date doesn't mean much. Not all electrolytic caps have to be replaced just normally crap brands and ones under heat or switching/filtering stress. If it was in service with big hours and there are problems after a few years then testing would be a good idea.

author: Electro Detective
author_rank: Super Contributor
timestamp: March 04, 2018, 11:43:02 pm
content: If you do a lot of cap work it may be time to consider getting an ESR tester to do in circuit tests (with unit off!)and comparisons amongst groups of same value capsThe really suss caps you will still have to unsolder one leg and test or just replace the old school waySometimes caps may have been replaced under warranty by manufacturer with different brands,or someone threw in some 'close enough' values for an expedient repair,you just don't know

author: Addicted2AnalogTek
author_rank: Frequent Contributor
timestamp: March 04, 2018, 11:58:04 pm
content: Quote from: jaunty on March 04, 2018, 09:37:25 pmdate codes are relatively simple and will usually be four digits printed on the cap. some of the brands have other digits included before or after the date code. Most that I've seen like this have had the four digit date code following some other digits that I don't know how to decode (and haven't bothered trying).Date codes though....AABBAA is the last two digits of the yearBB is the week out of the year it was manufacturedEx. 7742 is the 42nd week of 1977

author: David Hess
author_rank: Super Contributor
timestamp: March 05, 2018, 02:00:54 am
content: If you cannot read the date codes on the capacitors and they have not been changed, then instead read the date codes on the other parts to get an idea of the production date.

author: Cerebus
author_rank: Super Contributor
timestamp: March 05, 2018, 03:18:51 am
content: QuoteWell, I'd avoid doing it until you've hadthe talkfrom your electronics tutor. The one that begins "When an NPN transistor and a PNP transistor love each other very much...".Sorry, couldn't resist.

author: Shock
author_rank: Super Contributor
timestamp: March 05, 2018, 10:20:32 am
content: Quote from: Cerebus on March 05, 2018, 03:18:51 amI find that last comment very biased. They clearly weren't darlings.

author: KNSSoftware
author_rank: Regular Contributor
timestamp: March 05, 2018, 10:29:07 am
content: Quote from: Shock on March 05, 2018, 10:20:32 amNow now, I thought we were all better than this here, than to judge a couple of trannies; Grindr, Tindr, Wattever trips your switch

author: IanMacdonald
author_rank: Frequent Contributor
timestamp: March 05, 2018, 03:51:54 pm
content: Quote from: Cerebus on March 05, 2018, 03:18:51 amWell, if they're both trannies they should be in for a gay time.