Keithley 2100 AT SPEC MODE ERR +599 Repair - Page 1
Forum section: electronics / repair

author: FlyingHacker
author_rank: Frequent Contributor
timestamp: September 01, 2016, 05:14:52 am
content: Hi,My Keithley 2100 DMM (please do NOT post to this thread about how the 2100 sucks, blah, blah... for the price it is a really nice 6 1/2 digit meter, that has a GUI that is somewhat lacking) started throwing up an occasional error on startup. It would say AT SPEC MODE, and then if you went through the menus to errors you would see ERR +509.Apparently this error is a problem with the filter caps.From the Keithley forum, posted by Keithley employee:QuoteSo this is a known issue... Fun! This is what happens when you put trash "Stone" brand capacitors into a piece of test equipment.Well, mine is a few years old and bought off eBay; so there is no warranty. So I fixed it myself.Before and after pics:Look at the tops of those crappy Stone capacitors!My new Nichicons were a little larger. I will silicone them after a few days of use to make sure all is well.

author: FlyingHacker
author_rank: Frequent Contributor
timestamp: September 01, 2016, 05:16:04 am
content: I replaced most of the other Stone caps too. I did not have a few in stock, and will get those next time I go in.Don't you just love the design with caps right next to heat sinks on voltage regs, and right next to the transformer? I get they need to be near, but not quite so close, please, especially if you are going to use garbage caps.

author: FlyingHacker
author_rank: Frequent Contributor
timestamp: September 01, 2016, 05:18:24 am
content: Some of the culprits... (not that poor transistor... from another project).

author: Kleinstein
author_rank: Super Contributor
timestamp: September 01, 2016, 04:47:10 pm
content: It is interesting to see a meter that gives an error message for failing filter caps. Though the caps are so bad this is clearly visible. Bad caps in Keithley meters seem to be a common problem - not just this type.I would be nice to get the warning about too much ripply on the raw voltage (and thus likely bad caps) before the caps really fail, so you have time to plan service.

author: FlyingHacker
author_rank: Frequent Contributor
timestamp: September 01, 2016, 05:02:16 pm
content: Quote from: Kleinstein on September 01, 2016, 04:47:10 pmYeah, I was actually really surprised about this. But it was indeed a great thing to get the warning before they exploded all over and caused damage. Once I opened her up it was clear that the caps were indeed the issue.

author: adilmalik
author_rank: Contributor
timestamp: September 02, 2016, 04:17:12 pm
content: Just opened my unit, the capacitors are Rubycon's. I reckon they are fine?

author: FlyingHacker
author_rank: Frequent Contributor
timestamp: September 02, 2016, 05:15:06 pm
content: Nice.What is your serial number? Do you see any date codes on any ICs? Also, does it look like your board has been modified? (any marks/flux, etc. on the bottom?)The Rubycons are certainly way better ;-) However, they are still right next to heat sources. I just might check them every year or so. However, mine looked fine last time I opened it, which was about 10 months ago.At least the error warning happened on mine before catastrophic failure. Definitely don't ignore the error, even if it only happens once.

author: retiredcaps
author_rank: Super Contributor
timestamp: September 02, 2016, 05:19:37 pm
content: Quote from: FlyingHacker on September 02, 2016, 05:15:06 pmIn the infamous small form factor Dell P4 computers, Rubycon's/Panasonic didn't last either due to heat. Certainly, Rubycon are better than Stone. Picture of bloated Rubycon's in Dell from badcaps.net.

author: adilmalik
author_rank: Contributor
timestamp: September 02, 2016, 06:29:12 pm
content: Quote from: FlyingHacker on September 02, 2016, 05:15:06 pmNo flux residue what so ever, seems stock to me.How do i find the Serial number? no sticker in sight.PS: please read my tread, i have a favour to ask next time to open your meter. I suspect my caddock divider is bad, please have a look at the last post here when you canhttps://www.eevblog.com/forum/repair/keithley-2100-how-does-one-identify-a-burnt-smd-resistor-without-service-manual/

author: FlyingHacker
author_rank: Frequent Contributor
timestamp: September 03, 2016, 02:16:17 am
content: Anyone know if the electrolytics UNDER the shielding can be replaced without affecting calibration? They look like local storage, but I need to look up what chips they are bypassing.

author: FlyingHacker
author_rank: Frequent Contributor
timestamp: September 04, 2016, 10:41:21 pm
content: So a couple of the larger caps under the shield look like local storage for the RMS converter power input. I am guessing I should be able to replace those without affect the calibration much, if it all?Anyone an expert on meters?