Keithley 2015 self-tests - Page 1
Forum section: electronics / testgear

author: grumpydoc
author_rank: Super Contributor
timestamp: June 06, 2014, 05:14:09 pm
content: Is there any way to run a set of self tests on the 2015 as you can with the 2000.Looking at the service manual the 2015 only has the "Key" and "Disp" tests available from the front panel - no access to the "Built-in" test menu as on the 2000 and this certainly seems to be born out in practice.

author: jpb
author_rank: Super Contributor
timestamp: June 06, 2014, 05:39:16 pm
content: I think you're right>The repair manual says there are just the two front panel tests:http://exodus.poly.edu/~kurt/manuals/manuals/Keithley/KEI%202015%20Service.pdfI guess they couldn't build in a complete set of tests to include the THD bits so just skipped them all together - or perhaps they used microprocessor resources for the THD stuff that didn't leave enough for self tests.

author: Mark666
author_rank: Contributor
timestamp: June 06, 2014, 05:48:14 pm
content: Looking at the service manual for the 2000, it only mentions the same two tests?http://circuitslab.case.edu/manuals/Keithley_Model_2000_Multimeter_Repair_Manual.pdf

author: jpb
author_rank: Super Contributor
timestamp: June 06, 2014, 06:14:57 pm
content: Quote from: Mark666 on June 06, 2014, 05:48:14 pmIt lists all the other tests from page 2-18 on under troubleshooting - this section seems to be missing in the troubleshooting section of the 2015 manual.

author: Mark666
author_rank: Contributor
timestamp: June 06, 2014, 06:23:09 pm
content: Yes my error found it now. Its strange that they have omitted these tests on the 2015. Hopefully someone will have some more info on this.

author: jpb
author_rank: Super Contributor
timestamp: June 06, 2014, 06:48:27 pm
content: As an aside, Grumpydoc, I thought you'd just bought yourself a 2000 not a 2015?

author: grumpydoc
author_rank: Super Contributor
timestamp: June 06, 2014, 06:53:11 pm
content: QuoteErrr....OK, to expand on this:Thanks to some low prices on ebay at the moment I find myself the owner of a 2000anda 2015.The 2000 comes from a seller who doesn't appear to do all that much in the way of electronics but I have to say I was quite pleased with it - well packed in a double-wall box with probes and the original CD, bright display, passes all self-tests and seems fairly accurate on my DMMCheck/against my HP 3478The 2015 comes from the large batch recently sold on ebay. I think the buyers who got "never opened" ones got a good deal but this is one of the "lightly used" ones and I'm.........not sure.I wasn't impressed that it came parcelled in just bubble wrap - no box - but it seems to have survived mechanically. The VFD is not too bad but definitely dim/uneven in places. More worryingly with the input shorted on DCV I get a reading of about 80 counts (=8uV) compared with 0-2 on the 2000.My first thought is to use a shorter loop between the input terminals as I used a spare banana-plug to croc-clip lead which makes the loop about 2m (I just need to dig some spare banana plugs out). My second though was to run the self-tests but apparently there aren't anyThought 2a is that I am wondering whether swapping the firmware EPROMs from the 2000 to the 2015 would yield a useful result.My third thought is to re-cap it (especially given that Vincent says he's seen 2000's fry themselves with bad caps) but I'll have to order a set of parts so that will have to wait until next week.Edit: to start with can anyone with a 2015 confirm that it should read zero with the inputs shorted?

author: dr.diesel
author_rank: Super Contributor
timestamp: June 06, 2014, 07:14:21 pm
content: Quote from: grumpydoc on June 06, 2014, 06:53:11 pmMy in-cal K2015 reads about 000.00050mV (actual display reading - to reduce confusion) on Slow/Filter(10 readings) with 36" jumpers. Reads about the same with the Keithley 8610 cal shorting jumper as well.You can actually do the shorting cal independently of the full cal. If you were in the US i'd just mail you the cal shorting jumper!

author: grumpydoc
author_rank: Super Contributor
timestamp: June 06, 2014, 07:28:00 pm
content: QuoteAh, confusion increased by the fact that there seem too many digits there for a 2015, though vaguely reassured that you appear to be getting 50 counts with shorted jumpers.QuoteSadly I'm in the UK. Keithley do list the shorting plug as an accessory but at £48+VAT for four banana plugs it seems a bit excessive.Is there any compelling reason not to do it with four 4mm plugs and some heavy gauge copper wire?

author: jpb
author_rank: Super Contributor
timestamp: June 06, 2014, 07:39:40 pm
content: Quote from: grumpydoc on June 06, 2014, 07:28:00 pmI was looking at this for the K2000 as I was running the self-tests. The Fluke one is slightly cheaper at £30+VAT from Farnell but still rather pricey. (Also I don't know if the spacing is right.) I ended up using just stackable leads - four of them connecting all four sockets - this was sufficient to pass the self test.I was wondering whether or not to build one with some scrap copper I've got lying around and four quality banana plugs.

author: grumpydoc
author_rank: Super Contributor
timestamp: June 06, 2014, 07:44:19 pm
content: QuoteI was thinking of 4 banana plugs and some 2.5mm2copper wire soldered in the centre to make an "X"The self tests were happy with two quite long banana-plug to croc-clip leads with the crocs connected together.

author: dr.diesel
author_rank: Super Contributor
timestamp: June 06, 2014, 07:47:29 pm
content: Quote from: grumpydoc on June 06, 2014, 07:28:00 pmLOL, confusion acknowledged, mine is a 2010, for reference was the intent., sorry.

author: KJDS
author_rank: Super Contributor
timestamp: June 06, 2014, 07:49:14 pm
content: I've just tested a couple of mine, and also connected them to a Fluke calibrator to compare 10V measurements. The calibrator hasn't been caibrated in a while and it's reading a little lower than the other one I have which is more recently cal'd, but to swap them over would involve about 300kg of lifting and I've had a workout already today.I've also got a pile of boards with plugs that were originally on the rear of some of the 2015 I had, but could easily be modded to give a shorting plug. £12 each including VAT and UK shipping, PM me for details.

author: grumpydoc
author_rank: Super Contributor
timestamp: June 06, 2014, 08:01:14 pm
content: QuoteI thought you'd sold your 2015's?OK, I'm relaxing a bit on the reading with inputs shorted since the bottom one of Kevin's seems to be reading 50 counts. Also this one seems to be settling to around 40 counts.Plan at the moment is to try some contact cleaner on a Q-tip in the socket, then open it up and make sure all the connections are sound and then make a shorting plug and look at the "shorting cal" thing as well as a re-cap.The actual reading at 5V from the DMM check is pretty close to that on the 2000 - less than 100uV difference which is consistent with the specs for the 2000/2015

author: KJDS
author_rank: Super Contributor
timestamp: June 06, 2014, 08:44:51 pm
content: Quote from: grumpydoc on June 06, 2014, 08:01:14 pmI've still got a few, but I think I'm keeping what I have left. I'm still doing enough design contracting to want to have a few decent meters about.I am kicking myself for not buying several hundred when I had the chance last year. I've learnt from that and know not to miss out on that sort of opportunity when it next comes up.

author: grumpydoc
author_rank: Super Contributor
timestamp: June 06, 2014, 09:46:47 pm
content: QuoteNo problem.Back to not relaxed as the reading is really not very consistent. I wanted to get this unit formally calibrated but I'm not especially keen to repeatyour experienceof sending a unit back for cal and ending up with a substantial repair bill.Currently very tempted to swap the ROMs and try the self-tests as a 2000 - the service manual describes the firmware upgrade process and it's just swapping the two socketed EPROMs. Just worried that I'll brick both the 2000 and 2015.Ah - here's a thing. There's a firmware image for the 2000 inthis threadon the Keithley forums. Notquitethe latest but that shouldn't matter - if I can burn that into a couple of EPROMs I'll have a much lower chance of ending up with a pair of highly accurate bricks.Bit of a sub-project as, although my Dataman S4 can do the 27C020 but I'll need to build an adapter from DIP to PLCC so might take a bit of time.Edit: Hmmm, it seems that the forum member who prompted Keithley to make the firmware available has alreadybeen down a similar roadand lost his cal data. Don't think I want to do that. Ho hum.

author: dr.diesel
author_rank: Super Contributor
timestamp: June 06, 2014, 09:55:09 pm
content: Quote from: grumpydoc on June 06, 2014, 09:46:47 pmIf I jiggle the leads the reading can change up to 2x, then rest back down. At that level you need shielded cables/DUT box.

author: jpb
author_rank: Super Contributor
timestamp: June 06, 2014, 10:01:01 pm
content: Quote from: grumpydoc on June 06, 2014, 09:46:47 pmI wouldn't swap the ROMs. The 2015 ROM presumably expects the extra THD stuff to be connected/exist whilst the 2000 ROM knows nothing about it. The self test from the 2000 ROM might actually do something with the THD circuits rather than run the self-test properly.I may be completely wrong but if you swap the ROMs it might be an idea to remove the separate THD board at the same time to convert it fully to a 2000.

author: grumpydoc
author_rank: Super Contributor
timestamp: June 06, 2014, 10:43:15 pm
content: QuoteGood plan.However, TBH I've decided that there's too much chance of loosing cal data - it looks like the A20 firmware added extra cal steps and will wipe the old data for you. I could copy the firmware from the 2000 but there's no real reason to think that the two will hold the same data. AFAIK it's in an I2C EEPROM somewhere (but I haven't spotted it yet) - if I could back that up then maybe, but I don't have any tools which can do that.I'll go with ashortshorting plug and see if that improves things. I'm probably just being paranoid but 30 or 40 counts of noise when it should say zero or nearly so is bugging me that something isn'tquiterightI did wonder whether they remember the autozero setting (and if it could have been turned off) - it can only be set remotely and I can't see any annunciator on the VFD for it.

author: grumpydoc
author_rank: Super Contributor
timestamp: June 06, 2014, 10:46:01 pm
content: QuoteYes, I'm mildly surprised there's no guard terminal on these or on the 3478 for that matter

author: andy_silicon
author_rank: Regular Contributor
timestamp: June 07, 2014, 07:21:12 am
content: Quote from: grumpydoc on June 06, 2014, 09:46:47 pmThe user in that thread was me.Yes the A20 upgrade wipes your Cal data.There is a way to get your cal constants through GPIB - but I don't recall off the top of my head.( I'm happily away on holiday at the moment )One of my many started but never finished jobs was to work out the relationship of the Cal data in the eeprom to that of the constants returned via Gpib.Then you can read the data before upgrade - and potentially restore afterwards.Also - I have pretty good DC volts cal equipment - but little else - so I'd like to re-cal DC and restore my previous AC cal data.I admit I have 3 K2000's - two okay , one partially repaired.I have a fluke 731B , and a fluke dc calibrator (0-1000V) ( and a couple of other 10V references and standard resistors ).If there are any 3458 owners in west london who would measure some of my references I'd love to chat over a beer and a reference verification.

author: grumpydoc
author_rank: Super Contributor
timestamp: June 07, 2014, 04:41:35 pm
content: I'm still trying to get my head around whether there's an issue with this 2015 or whether the behaviour falls into "as expected".I now have a short shorting loop made from 2 gold-plated banana plugs and 10cm or so of 1.5mm2copper wire.Here is what I observe:For the 2000 I get a display which shows, on the 100mV range a reading in the approx range 1.0-2.0uV (10-20 counts) which doesn't seem to change much whether I choose slow, medium or fast update rates.For the 2015 it's not quite so consistent, but in slow and medium update rates I get similar readings (but can vary from single digit to 30-40 counts). If I set it to fast I see complete chaos in the last 3-4 digits with the 4th digit flicking between 0 and 1, occasionally 2. Filtering cuts this down to the last two digits being unstable and the third-least significant digit ranging from 0-2.If you look at the spec there is this table:RATEREADINGS/SDIGITSRMS NOISENMRRCMRR10V Range10PLC(slow)56.5<1.5uV60dB140dB1PLC(med)506.5<4uV60dB140dB0.1PLC(fast)5005.5<22uV---140dBI presume the noise will be the same on the 100mV range in which case what I'm seeing is probably within spec -- especially given that those are RMS figures for noise and the peaks will be higher -- but at the upper limit for noise figures compared with the 2000 which is actually quite good in this respect.I think.......

author: grumpydoc
author_rank: Super Contributor
timestamp: June 08, 2014, 08:21:47 pm
content: Back to the subject of self-tests.I've now dumped the ROMs from the 2015 (needed to make a 32 pin PLCC to DIP adapter hence the slight delay) - interestingly the string "TEST: BUILT-IN" appears in the image as do the three prompts "REMOVE ALL INPUTS.", "INSERT 4 WIRE SHORT." and "SHORT HI TO AMPS." which appear as part of the test sequence.Nothing to say that the code is there, of course, but there's more than 64k of blank space at the end of the image so if they took the self-tests out I'm not sure that the reason was lack of space in the ROM.While we're here a reminder that the 2000 has been substantially reverse-engineered and schematics are available - seethis poston the blog.Also, there wassome discussionabout firmware revisions following the batch that KJDS sold - mine is B17. I've attached the binary files in case anyone wants to play.

author: neslekkim
author_rank: Super Contributor
timestamp: June 08, 2014, 09:18:47 pm
content: Did you buy from the uk seller that have some lately?, faria... ?was wondering a bit about buying, but seller wants £195 for an used (no information about condition, age, no pictures etc), and £100 for shipping.. which in total will add an extra £100 in tax'es before I can put my hands on one..Are these very heavy?

author: KJDS
author_rank: Super Contributor
timestamp: June 08, 2014, 09:26:06 pm
content: Quote from: neslekkim on June 08, 2014, 09:18:47 pmThey weigh 7kg and are shippable in a box that's 49cm x 33cm x 25cm with a decent amount of packing round them.I suggest that they should be able to provide subtantially better shipping rates if asked. If the £99 is the rate displayed on ebay that may be to cover shipping anywhere in the world. I've had a couple of heavy items bought buy people in obscure places, 20kg in a large box to Bolivia came as a shock.

author: neslekkim
author_rank: Super Contributor
timestamp: June 08, 2014, 09:28:35 pm
content: I asked for shipping to Oslo,Norway, got £95, the seller does not answer all my questions either, so I'm not very happy about that..

author: grumpydoc
author_rank: Super Contributor
timestamp: June 08, 2014, 09:46:48 pm
content: QuoteYes, that's the sellerQuoteThey are fairly heavy for their size - The official shipping weight is 5kg but that will be in Keithley's original box which you'd want in a larger box, plus packing so KJDS's estimate of 7kg seems reasonable.QuoteThe condition my mine was reasonable - there are a couple of small but deep scratches on the case (i.e deep enough to go through the powder coating) but probably par for the course for 2nd hand stuff. The display still has its protective film.As noted above packaging in the UK might leave a bit to be desired - I'd check how they plan to package one for international travel before buying.IC date codes in mine suggest a late 2007/early 2008 build which is consistent with the "never used" ones they also sold (a much better buy, especially if you got one of the sub-£300 ones but they're holding out at £695 at the moment).Last cal date was Nov 2008 for mine. Accuracy is yet to be determined but DCV matches the 2000 I also bought recently and my 3478 well - close enough tosuggestit's still in spec. Again as already discussed mine seems a bit noisy on the input but probably within spec.QuoteThat isn't going to build confidenceI confess I probably wouldn't have bought one except for the fact that it appeared that people had bought the new ones and reported on the forum that the seller seemed kosher - at least to the degree of having multimeters to sell and shipping the mout reasonably quickly.

author: neslekkim
author_rank: Super Contributor
timestamp: June 08, 2014, 09:53:52 pm
content: Good, seems the product is ok then, they didn't ship in the original packing I guess, since they are used?I have an 34461a, so I'm kinda set, but it's always cool with equipment, need to sleep on it I guess.

author: grumpydoc
author_rank: Super Contributor
timestamp: June 08, 2014, 09:58:10 pm
content: QuoteAt the price they want I hope you don't need more than a short nap.I have no idea how many they've actually got - two more got listed this evening and both went within about an hour. They have another used one listed at the moment........

author: jpb
author_rank: Super Contributor
timestamp: June 08, 2014, 10:24:04 pm
content: Quote from: grumpydoc on June 08, 2014, 09:58:10 pmI'm probably mad given your mixed experience, but I've gone and bought one - at £195 it seems worth the risk. I'll recap it I think though looking at Dave's video tear down it is a bit more complicated to get at than the 2000 and more caps to change. Perhaps this will be an excuse to get a proper de-soldering tool.

author: neslekkim
author_rank: Super Contributor
timestamp: June 08, 2014, 10:48:44 pm
content: these are 220volts, right?

author: grumpydoc
author_rank: Super Contributor
timestamp: June 08, 2014, 10:59:01 pm
content: Quote£195 is pretty cheap, you have to admit.I'm toying with do I/don't I on the recap - generally try to avoid unnecessary work as it can cause more problems than it fixes.On a loosely relayed note does anyone know of a good m68k disassembler which runs on Linux? So far I've not really found anything useful - GNU objdump can do it but on raw binary files it is not good at telling the difference between executable code and data.QuoteMine was set at 220 - they can be set for 110/120/240 as well.

author: neslekkim
author_rank: Super Contributor
timestamp: June 08, 2014, 11:11:26 pm
content: Quote from: grumpydoc on June 08, 2014, 10:59:01 pmWhat did you pay for shipping in UK?, and I guess you don't pay VAT when buying from ebay?For me, it's around 395 shipped and taxed up, But I guess that price is kinda ok also, for what one get?

author: grumpydoc
author_rank: Super Contributor
timestamp: June 09, 2014, 07:35:20 am
content: QuoteIn the UK shipping is included.FWIW I think £100 is excessive for shipping - I just checked on Interparcel and their standard 2-5 day service to Norway is £27+VAT for an 8kg parcel with the dimensions that KJDS suggested.QuoteIt's still a reasonable price - just no longer a bargain.

author: jpb
author_rank: Super Contributor
timestamp: June 09, 2014, 09:47:33 am
content: Quote from: grumpydoc on June 08, 2014, 10:59:01 pmI'm glad I did it with my Advantest though it was probably unnecessary as the caps looked fine - I didn't have a meter to test them at the time - for two reasons. First (and this may just be my imagination) but the display looked better afterwards (brighter). Secondly, even the official manual listed replacement of the caps as something that should be done every five years (this is probably a bit over the top but must be based on some experience).Quote from: grumpydoc on June 08, 2014, 10:59:01 pmI don't but you may be able to do a bit of presorting by searching on jump commands and the initial (zero address?) vectors to get the addresses of known code.Quote from: grumpydoc on June 08, 2014, 10:59:01 pmWith my 2000 I initially thought the switch had two positions 110/120 and 220/240 so I left it for a short time in the 220 position before discovering the separate 240V position. Fortunately it doesn't seem to have done it any harm - at least it passes all self tests and seems to measure sensible values.

author: neslekkim
author_rank: Super Contributor
timestamp: June 17, 2014, 11:14:47 am
content: Got mine now, looks ok, small scratches on the top, not much, need to clean the frontpanel/display (the pictured one on ebay was flawless, oh well, same pic on all)Not sure how it works yet, the numbers are rolling all over the place, pressing range button makes it display 3.xxx or 0.003xxx and so on, so I need to get it home first to test it with probes.Firmware seems to be B15 A02, latest is B17?, what is the A20 thingy I saw some discusions about?The stickers on it only says calibration is void if they are removed (GSM Mobile calibration?), but no date of calibration on it externally.On the back, almost covering the voltagetselection, there is an sticker, "electrical safety check, 16. oct 2008)".Is there other ways to find out how old it is?Are there anything I need to consider if I pop the hood on this? (for cleaning etc)Something I need to check?, batteries etc? (I read about some meter that looses its calibration if one remove the battery, don't remember which meter though)Seller sent it through dhl express shipping, so i'm expecting an hefty bill from them soon (for tax etc)

author: grumpydoc
author_rank: Super Contributor
timestamp: June 17, 2014, 12:24:52 pm
content: QuoteLook inside at IC dates.Also shift, then cal takes you to a menu where you can see the calibration dates.

author: neslekkim
author_rank: Super Contributor
timestamp: June 17, 2014, 01:22:10 pm
content: 10/18/08and count = 12

author: neslekkim
author_rank: Super Contributor
timestamp: June 17, 2014, 03:48:28 pm
content: Compared my 2015 with my agilent 34461a now, on DCV its bang on, last two digits are differenttested an cheap 100 ohm resistor,99.49 on 2015, and 99.58 on the agilentThink I need to test better than with one resistor, but that is what I'm able to right now, but it seems to be good, considering last calibration october 2008..

author: jpb
author_rank: Super Contributor
timestamp: June 17, 2014, 05:16:59 pm
content: I've done a quick measurement of the input impedance relative to my much newer K2000 (I intend to do more thorough tests when I have more time)I connected the two meters in series and applied approximately 30V.You can see that the resistance of both is almost equal - they each drop close to 15V.(I wanted to do this test as a "before" so I know if I mess it up when I open it up to replace capacitors)EDIT : this effect (of dropping voltage) turns out to be due to auto range switching with different impedances on the different ranges - if I manually fix the range to 10V then the total Voltage is that of the power supply (18.02V vs 18.04V on power supply meter) see attached photos.

author: grumpydoc
author_rank: Super Contributor
timestamp: June 17, 2014, 05:23:29 pm
content: QuoteIn some ways buying an older high precision DMM is not a bad thing as the reference tends to drift less with time.I think the advice is to re-cap the early 2000 series DMMs though.

author: neslekkim
author_rank: Super Contributor
timestamp: June 17, 2014, 05:42:55 pm
content: Quote from: grumpydoc on June 17, 2014, 05:23:29 pmIt was very interresting to see that it was so correct on the measurements that I did comparing with the agilent, which is brand new.I cannot remove one of the screws under it though, for some reason it have rusted, the other screw is not, and there is no other signs of rust..Btw: in DCV mode, it is around 3.1xx volts when no probes are attached, isn't that kinda a lot?It goes straight down to 0 when I keep the probes together tough..

author: jpb
author_rank: Super Contributor
timestamp: June 17, 2014, 07:15:11 pm
content: Quote from: neslekkim on June 17, 2014, 05:42:55 pmMine goes to about 0.8V which is much more than my other meter but it doesn't seem to affect any measurements and it might in fact be a good sign - i.e. the impedance is so high that charge collects without any path to ground.

author: AndyC_772
author_rank: Super Contributor
timestamp: June 17, 2014, 07:56:49 pm
content: Quote from: neslekkim on June 17, 2014, 05:42:55 pmExactly the same here. Interestingly, my older model 2000 reads a negative voltage and drifts around a lot more when unconnected, though both read within a couple of counts of each other when connected to an actual voltage source. I don't feel there's any evidence of a problem.