Keithley 2000+2015 THD - Page 1
Forum section: electronics / testgear

author: costas
author_rank: Contributor
timestamp: September 26, 2012, 05:09:29 pm
content: Hello,I have two flawn Keithley multimeters:2000 and 2015THD. For the 2015THD I would need the content of the two memories of 27C020 ( U156 , U157 version B07 ). It starts when I put the memories from 2000 but i don't think it is working in the normal parameters...where could I find the memory content? I am willing to trade the Keithley 2000. For the Keithley 2000 I have found the following errors when I run an internal test:101.2101.3200.1200.2201.1201.2300.1301.1301.2302.1302.2303.1303.2304.1400.2401.2402.2403.2500.1500.2600.1600.2601.2Do you think that there is a possibility for reparing the Keithley 2000? Maybe with a scheme...but I didn't find one! I could really use some advise from more experienced peers in the field!Thank you very much!Costas

author: free_electron
author_rank: Super Contributor
timestamp: September 26, 2012, 08:01:08 pm
content: if you have all of those errors then most likely one of the supply voltages is missing so the analog section is misbehaving.to actually have all these errors in 'part defects' half of the parts would need to be broken...check the supply voltages.

author: costas
author_rank: Contributor
timestamp: September 27, 2012, 07:24:37 am
content: Thank you for reply , I will verify the power supply ...About 2015 working memory dump where I can find ? Maybe somebody try to read from personal device .Costas

author: muvideo
author_rank: Frequent Contributor
timestamp: September 27, 2012, 07:35:08 am
content: Hello, I have a 2015, check my teardown in this forum:https://www.eevblog.com/forum/product-reviews-photos-and-discussion/keithley-2015-teardownI think my fw is a different revision, dont know ifthey are compatible and board rev. are the same.I have a (low cost) eeprom programmer, but I donthave a plcc adapter around now.If I find how (safely ) dump I'll send you the dumps.Fabio.

author: costas
author_rank: Contributor
timestamp: September 27, 2012, 08:22:23 am
content: Hello,I saw your teardown , I found very interesting ... your version is B15, if it works with dump from 2000 do not see why it would not work with a newer version from 2015, however if you have a backup dump is great for "accidents". To check if they read well you can clone in two sites 29F020 flash (29F040, or eeproms 28F020, 28F040, 28C020 , 28C040) that you have on hand without disturbing the OTP's whether or not reading and writing wellAnd I'm still use a low cost programmer (willem) I was able to read well, with professional programmer - labprog 48 - I was just checking errors for AT27C020Thank youCostas

author: costas
author_rank: Contributor
timestamp: September 27, 2012, 06:55:05 pm
content: Quote from: free_electron on September 26, 2012, 08:01:08 pmAt Keithley 2000 I measured all voltages after repair manual is within the tolerances , reference voltage of 7V (U141 LM399 ) which I suspected is 6.98 , the more I replaced several of the analog IC's (mux-u163, u165 ADC, u113, u115, u129, u166, u132 operational amplifiers) but errors not disappeared . At the same IC's Keithley 2015 functions without error , or something I'm missing and do not know what , any idea is welcome.Thank youCostas

author: muvideo
author_rank: Frequent Contributor
timestamp: September 28, 2012, 10:15:46 am
content: Quote from: costas on September 27, 2012, 08:22:23 amHello, only problem I dont have an adapter now.I should find time to make one since I have the sockets,the safety issue is because I know myself, mistakes are certainFabio.

author: costas
author_rank: Contributor
timestamp: September 28, 2012, 10:49:49 am
content: Hello ,I can send you by post , ready adapter or pcb for make the adapter , just tell the address .Thank youCostas

author: muvideo
author_rank: Frequent Contributor
timestamp: September 28, 2012, 11:24:04 am
content: Contacted you by PM.Fabio.

author: costas
author_rank: Contributor
timestamp: October 06, 2012, 05:05:52 pm
content: Quote from: free_electron on September 26, 2012, 08:01:08 pmHelloFor the many errors found defective circuit is about R271 = TF-245, but do not know what the equivalent circuit can replace, repair manual specified as RES NET circuit. I compared it with ohmmeter with a good track but we found significant differences may be a range of electrical resistance, but do not know any pin configuration and no values??. As measured with the ohmmeter does not look like a typical resistive area.Any idea is welcome.Thank you very much costas

author: muvideo
author_rank: Frequent Contributor
timestamp: October 06, 2012, 05:52:07 pm
content: I didnt find info, it seem a resistor network, could it bepurpose built (or simply marked) just for keithley?Do they sell spares, or you are forced to go to a repair centre?Maybe the cost from keithley is not too high.Fabio.P.S. I didnt forgot about the roms

author: costas
author_rank: Contributor
timestamp: October 06, 2012, 06:23:27 pm
content: Quote from: muvideo on October 06, 2012, 05:52:07 pmHello Fabio ,Unfortunately I have none of recommended possibilitiesLast Monday I sent out PCB's , probably next couple weeks will get itWBRCostas

author: costas
author_rank: Contributor
timestamp: October 09, 2012, 06:51:19 pm
content: Today I started very determined to try again solving TF245 problem, I desolder again good IC and did all the measurements possible with ohmmeter. its internal schema I do hope is correct and complete although I did not see any logic in the resistance arrangement, maybe someone has seen such a network of resistance and find an equivalent. Compared with a good IC , I found resistances 9K and 1k interrupted from terminal 9 and resistance of 27.5 k of pins 10-12. ExperimentaI l soldered the respective IC pins external resistance 0.4w 5% 1k, 9.1k, 27k, then I ran the checking test and surprise all errors are gone (Before running up test should expect to better cool the area where I did tinning)Course is only a makeshift solution using ordinary low precision resistance. .. the idea would be to find an equivalent for TF245 , but …after my schematics I do not think is possibleWBRCostas

author: muvideo
author_rank: Frequent Contributor
timestamp: October 09, 2012, 07:30:36 pm
content: Pins 6,7,8,9 seem a voltage divider with 1:10:100 ratio.As for 1->4 13->16 are that measured values or howyou imagine the resistors connected inside?I think that there are many possible arrangementsfor inner resistors for that part of the network.Also, are you sure you are measuring resistances only andnot some semi junctions around?You can test some of the values at different voltages to seeif the current is proportional to voltage to be sure.Fabio.

author: costas
author_rank: Contributor
timestamp: October 10, 2012, 06:22:32 am
content: TF245A's scheme represents measurements performed by me between IC pins and no resistance positions, I made another set of measurements (scheme "C") between pin 16 – common - and pin 1, 2, 3, 4, 15, 14.13. Comparing measurements the scheme "A" and the scheme of "C" resulting scheme "B" that corresponds to the positions and value of the resistance . If somebody have a different opinion please tell us .WBRCostas

author: michl
author_rank: Newbie
timestamp: October 28, 2012, 12:13:48 pm
content: Hello Costas,I have here a broken Keithley 2010 that shows overrange error after switching the device on. After some hours of 'warmup' the device will operate normally. The 2010 also contains this TF-245 and after reading your post I measured the resistances of my TF-245 and realized that there was no connection(resistance) between pin 9 and 7 and pin 10 and 12. I added some external resistors according to your measurement and the device is now behaving different. After startup it shows '---------' for some minutes and then measures without going to overrange (but the calibration is no more valid). So it seems that also my TF-245 seems to be broken. Did you already contact Keithley if they sell this resistor network as a spare part? Is your device working properly with the external resistors?Michael

author: costas
author_rank: Contributor
timestamp: October 28, 2012, 05:10:03 pm
content: Hello ,My device is work properly with external resistor , i contcat Keithley but I not got any answer ....WBRCostas

author: costas
author_rank: Contributor
timestamp: December 19, 2012, 05:02:57 pm
content: Hello ,For Keithey lowersI find TF 245 and work OK , in China ...olso I buy Fluke 776195 IC and work okther is the linckE-mail: sales06@stj-tech.comMSN: stjtech06@hotmail.comWebsite:www.stj-tech.comThe price is ok , under 5$+ delivery cost...wbrCostas

author: Rick
author_rank: Frequent Contributor
timestamp: December 31, 2012, 09:29:25 pm
content: I hope my question does not come late.You seem to have fixed your device.Another person on Internet does not seem to have been able to fix totally his problems with his DMM (other problems).I wonder if it is realistic for a person like me with almost no experience in such repairs to think he will be able to fix a totally broken Keithley 2000 with no schematic. I think there are instructions for troubleshooting in the service manual as well as board layouts but some parts have enigmatic names apparently internal to Keithley. I am very much tempted... but does not dare.What would you recommend? To stay away? I may have better chances with Flukes but those ones are way too expensive. Sellers willing to sell broken dmms for 4-500.

author: costas
author_rank: Contributor
timestamp: January 01, 2013, 11:31:33 am
content: Quote from: Rick on December 31, 2012, 09:29:25 pmHelloHappy New Year !If you can or not fix it , you can not know unless you try. Besides some experience you must have other helpful items:1. working equipment: a good solder-desodering station with hot air , oscilloscope, flash-EEPROM programmer with useful adapters , another multimeter for tests and measurements (devices that know how to work somewhat)2. ambition and time to repair3. friends with whom you can discuss about the topic.4. a strategy for abording repair without schemeif you want I can tell my srategia.WBRCostas

author: Rick
author_rank: Frequent Contributor
timestamp: January 01, 2013, 02:03:41 pm
content: Hi Costas,Happy new year.I still need to buy a DSO and a desoldering station with a vacuum pump (the others (solder wick, heat gun) do not work for me, I screw up the stuff I desolder), besides that I will also need a programmer (which adapters should I buy?). I realized that.Sure, please tell me your strategy as you have realized a successful repair.

author: Rick
author_rank: Frequent Contributor
timestamp: January 01, 2013, 05:01:58 pm
content: Can I choose one of the following as a flash-EEPROM programmer?http://www.batronix.com/shop/programmer/eprom-programmer.htmlWould the cheapest one do the job or... ?

author: costas
author_rank: Contributor
timestamp: January 01, 2013, 09:32:24 pm
content: Quote from: Rick on January 01, 2013, 02:03:41 pmIf you have to buy all that just to fix a DMM does not deserve , better buy a good DMM.Is good programmer from BATRONIX , for beginners good one with 32-pin socket .... but in the future the 48 pins cover several new flashes at 1:1 universal adapters that you can use , much cheaper or easier to built. For the first few adapters you need: PLCC32 to DIP32, PLCC32 to DIP28, SO8 to DIP8, SOP28 to DIP28 .Generally large my repairs method without schema is simple :1. looking on the net as much documentation with error coded block diagrams, interpretation of error codes etc..2. see what kind of ICs is designed device , search and list the ICs pin configuration, so I know which pins is for supply , which pins is for the communication bus , which is input pins output pins ... etc3. Make copies of all flash and eeprom to restore if something happens on the software side.4. take measurements on the power pins to each integrated circuit, with the oscilloscope check whether or not the supply voltage ripple.5. with ESR-Capacimeter check electrolytic capacitors values in circuit6. with oscilloscope check digital signal amplitude on the ICs imput-output pins , bus terminals, swing on microprocessor X-tal.. etc7. concluded and try locating defects partswhere are you from ?WBR Costas

author: Rick
author_rank: Frequent Contributor
timestamp: January 01, 2013, 09:53:39 pm
content: I was going to buy a DSO and a desoldering station anyway because I have no oscilloscope yet. Only the EEPROM programmer will be an additional cost and I can use it in a future project who knows. I have an ESR_meter and 2 capacimeters besides that some of my DMM's (I will have 14 now with the new Bench meters I bought, including the dead 8800A/AF) can measure capacities. So I don't need a DMM but I will be having fun with "repairs".Have you been able to identify all parts with their real names? A guy was mentionning a JFET with a Keithley codename then he discovered what it was.I am in Istanbul. You must be from Greece. Right?I noticed the memory chips are 32 pin ones. So the 32 or 40 pin EEPROM programmers are ok, I suppose.Thank you very much for your advice.One last thing you run the copy operation from a PC to which you connect your programmer right? This is how ignorant I am sorry:)

author: costas
author_rank: Contributor
timestamp: January 02, 2013, 09:29:57 am
content: Quote from: Rick on January 01, 2013, 09:53:39 pmIf you want to get serious about service and you a fan BATRONIX , I recommend BATRONIX BX48 Batego II. I have a Labprog 48LV from ELNEC, but it is pretty old and not updated software for it , of course I have a many other homemade programmers who helped in many cases ... often with a programmer who knows only simple generic algorithm can read customised memory . Professional programmer read the ICs ID , if you not choose correctly from the list do not read itWBR.Costas

author: Rick
author_rank: Frequent Contributor
timestamp: January 18, 2013, 10:11:11 pm
content: Quote from: costas on September 26, 2012, 05:09:29 pmI have exactly the same errors as you.I have not measured anything yet.May be the same problem?My Keithley 2000 shows overrange and does not measure anything at all: volts, amps or resistancesI shall let it run a few hours to see if I observe the behaviour mentioned by Michl.Besides that inOhm 2: it shows overflow or 0.0117 OhmOhm4: overflow then a continuously switching relay sound with 0.087959 displayedfreq: 0.0 mHzACI: overflowDCI: 0.20660 AACV: overflowDCV: 10.506 V and as you change the range, the decimal point moves backward or forward.in auto mode DCV: 10.5557 or overflow

author: LEER333
author_rank: Contributor
timestamp: August 17, 2023, 05:02:23 am
content: try to replace AD

author: kloetpatra
author_rank: Regular Contributor
timestamp: August 18, 2023, 07:55:26 pm
content: after more than 10 years he probably had the time to replace every component