Need Help for Backup  Calibration Data Keithley 2015 - Page 1
Forum section: electronics / testgear

author: letron77
author_rank: Contributor
timestamp: July 14, 2019, 01:57:35 pm
content: Hello everyoneI am trying to fix a 2015 Kiethley that is stuck.Its display reads "No comm link"Before any intervention I decide to save the firmware and files of settingI have already read several post very interesting on this siteI bought a TLC866 IIIt allowed me to back up ODD and EVEN firmwareBy cons I do not know how to save the data "instrument setup and calibration constant" which is on the eeprom 24lc16b (U136)on this page it is about the parametric data backup of a k-2001 by realizing a "DIY I2C dongle" to connect to the TLC866:https://www.eevblog.com/forum/testgear/restoration-glory-of-keithley-2001-dmm/msg384347/#msg384347Can someone tell me how to realize it?Is the procedure the same on a 2001 and 2015?Should it desolder 24lc16B?in advance thank you for your helpAlain

author: MadTux
author_rank: Frequent Contributor
timestamp: July 14, 2019, 04:43:25 pm
content: Should be a similar procedure. I would avoid soldering, whenever possible (due to cleaning the board from flux).It's important to dump calibration data before playing with different firmware versions, otherwise it will soon display "Error" on display. Happened to two broken K2015 that I repaired. K2015 is a pain to calibrate, because of all the features like AC current

author: letron77
author_rank: Contributor
timestamp: July 14, 2019, 05:33:24 pm
content: thanks for these tipsBut I just realized that the welded eeprom U136 (24LC16B) is very very small and does not allow to fix contact clamps on these pins.It is much smaller than the eeprom X24C16P which is in the K-2001 and on which we can fix clamps!Do you even have a solution to advise me in order to save the configuration information on this chip?From Service manual :Semi-permanent storage facilities include NVRAM U136. This IC stores such information as instrument setup and calibration constants. Data transmission from this device is done in a serial fashion.

author: MadTux
author_rank: Frequent Contributor
timestamp: July 14, 2019, 07:29:23 pm
content: Perhaps such a clip?https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2334524.m570.l1311.R1.TR11.TRC1.A0.H0.Xsoic8.TRS0&_nkw=soic+8+clip&_sacat=0&LH_TitleDesc=0&_osacat=0&_odkw=so+8

author: letron77
author_rank: Contributor
timestamp: July 15, 2019, 03:26:00 am
content: Thanks - I have just by oneI resumed contact when I would have received

author: picburner
author_rank: Frequent Contributor
timestamp: July 15, 2019, 06:20:47 am
content: You don't have the space to insert that big soic8 adapter, you have a big capacitor on the side.To backup my k2010 eeprom I used three adapters like the ones in the picture.You just have to connect gnd, sck and sda only and not connect the 5Vcc (pin8 eeprom) to the programmer!You also need to keep the cpu reset to gnd and turn on the dmm (the programmer could never supply the 5Vcc to the whole digital part of the dmm!).

author: letron77
author_rank: Contributor
timestamp: July 15, 2019, 09:40:08 am
content: I understand when you talk about connections gnd, sck and sdaHowever, I do not understand when you say:"You also need to keep the cpu reset to gnd"(Should it short circuit some of the CPU's legs)and what is "DMM"?

author: picburner
author_rank: Frequent Contributor
timestamp: July 15, 2019, 11:07:16 am
content: In practice you have to do the same thing as TiN did, as in the pic you linked in the first post, you have to make a connection between "Digital Ground" and "Reset". You have to find these references in your Keithley 2015 because in Keithley 2001 and Keithley 2010 they are in different places.DMM = Digital Multi Meter (Your Keithley 2015...)TP106 could be "Digital Ground" but you have to check if it is connected to pin4 of U136.

author: letron77
author_rank: Contributor
timestamp: July 15, 2019, 01:02:34 pm
content: Ok for these clarificationsI'm going to look at DMM's SM to find the earth contactsHowever I will have to wait for the delivery of the adapter to connect to the chip because no clips can connect to these pins

author: picburner
author_rank: Frequent Contributor
timestamp: July 15, 2019, 01:50:56 pm
content: With the right grabber clips there is no problem to make the connection, look at my pics.In the meantime I think I found the "Reset": it is near U167.In fact U167 is a MAX809 (pin2 = /Reset).Check that the resistor R334 (on the opposite side to U167) is connected to pin48 of cpu MC68306, if it is true this is the "Reset" to use.

author: letron77
author_rank: Contributor
timestamp: July 15, 2019, 03:46:09 pm
content: it's very nice of you to have taken time to make these photos and explanations!Can you give me the references of your grabber clips because mine are too big. I will buy the same tomorrow.To verify this:"Check that the resistor R334 (on the opposite side to U167) is connected to MC68306, if it is true this is the" Reset "to use."Can I use a Ohm meter?

author: letron77
author_rank: Contributor
timestamp: July 15, 2019, 04:49:12 pm
content: I used an ohm meterThat's what I already found as contact between the terminal of the resistor 334 and the legs of the MC68306 cpu.Is it leg 48 that I indicated?

author: picburner
author_rank: Frequent Contributor
timestamp: July 15, 2019, 05:36:41 pm
content: My grabber clips: EZ-HOOK XKM Digi-Key code 461-1009-ND (but the Tektronix clips I showed you earlier are also good).Yes, the pin 48 is the last marked one in your pic (and in my card also there are other pins connected together).You must connect the reset to gnd so that, when you turn on the dmm, the cpu will not interfere with the TL866.

author: picburner
author_rank: Frequent Contributor
timestamp: July 15, 2019, 06:01:38 pm
content: I forgot one important thing: check that 5Vcc is present at the U144 voltage regulator output, otherwise it is not possible to read the eeprom on board.Since "No Comm Link" indicates a malfunction of the digital part of the dmm it is better to check that at least the power supply is present!

author: letron77
author_rank: Contributor
timestamp: July 15, 2019, 06:25:30 pm
content: Ok, I am going to control the voltage of u144However if I understand correctly I must connect the pin "reset" of R334 (which you have indicated on a previous photos) on the chassis of the device (the ground)

author: letron77
author_rank: Contributor
timestamp: July 15, 2019, 06:27:52 pm
content: u144 power supply is présent (4.91 v)

author: picburner
author_rank: Frequent Contributor
timestamp: July 15, 2019, 06:41:45 pm
content: Quote from: letron77 on July 15, 2019, 06:25:30 pmYes and even the instrument chassis is fine as digital ground.

author: letron77
author_rank: Contributor
timestamp: July 15, 2019, 06:59:13 pm
content: well taken noteI'll wait to receive my grabber clips I think at the end of the week and you recontacte when I did my tests againthank you

author: letron77
author_rank: Contributor
timestamp: July 31, 2019, 12:23:16 pm
content: Hello,I received my grabber clips this morningI connected as shown (see photos)However I have an error message "Pin Dectect error"(in principle this PIN is not connected!)

author: picburner
author_rank: Frequent Contributor
timestamp: July 31, 2019, 02:02:14 pm
content: The TLC866 does the test to see if all the pins are connected correctly.You need to disable this feature, in this case you don't need it.

author: picburner
author_rank: Frequent Contributor
timestamp: July 31, 2019, 02:17:00 pm
content: I looked at the program menu but my programmer is an old TL866 (the previous model of yours) and this feature is not present.So I can't tell you how to disable the pin check.

author: letron77
author_rank: Contributor
timestamp: July 31, 2019, 04:28:30 pm
content: Hello PicburnerIn the software I uncheck the otpion "Pin detect"after I could perfectly read the eproom!Thank you for your precious helpI will be able to dismount it now.Indeed, every time I turn it on it tells me "no comm link"If you were in my place by what control would you start?

author: picburner
author_rank: Frequent Contributor
timestamp: July 31, 2019, 07:13:45 pm
content: As I mentioned earlier "No Comm Link" is generated by the display/keyboard controller when it fails to communicate with the MC68306 CPU.So it's in the area around this cpu that you have to look.Check that Y101 (should be 16MHz) works, if you have an scope check if there are signals on the pins /CS of the eprom and sram.On the TiN website (xdevs.com) you can find the Keithley 2000 schematics which, at least in the digital section, is very similar to your 2015.If you can shot some pics of the instrument logic section and power supply so I can tell you if I see any anomalies.

author: letron77
author_rank: Contributor
timestamp: August 01, 2019, 12:03:43 pm
content: The frequency of Y101 is 14.75 Mz (Only the connection at the top left, for the other 3 connections the frequency is at 0 Mz)Can you give me the reference of the Eprom and Sram that I have to test?

author: picburner
author_rank: Frequent Contributor
timestamp: August 01, 2019, 01:58:52 pm
content: yes, you're right the frequency of y101 is 14.75MHz so that's fine.If you can shot a picture of your instrument pcb so I can tell you where to look for.The pictures you've taken before are too localized and the others are hidden by the TLC866...I don't have a Keithley 2015 but I have one 2001 and one 2010 so the my references are different.

author: letron77
author_rank: Contributor
timestamp: August 01, 2019, 03:46:35 pm
content: - General view: 1 404.jpg- Detailed view (the 1404.jpg in two parts) 1400 and 1402Do I have to dismount this card to also take pictures of the electronic card which is just below?

author: letron77
author_rank: Contributor
timestamp: August 01, 2019, 03:47:51 pm
content: here is 1404 view

author: picburner
author_rank: Frequent Contributor
timestamp: August 01, 2019, 05:37:30 pm
content: have you tried extracting U156 and U157 or have you found the two IC like this? I see signs on both.I don't understand the firmware version, it's usually written on the labels on the two ICs but I don't see it here.Edit:By enlarging the first picture, your firmware would look like B15, so it's older than the one I gave you.The Keithley 2015 service manual says:"During the power-on sequence, the Model 2015 will perform a checksum test on its EPROM(U156 and U157) and test its RAM (U151 and U152). If one of these tests fails, the instrumentwill lock up."I would concentrate on this since the CPU has its clock.I am attaching the B17 firmware so, if you have two other at27c020, you can check if the firmware is corrupt.

author: picburner
author_rank: Frequent Contributor
timestamp: August 01, 2019, 06:01:35 pm
content: Quote from: letron77 on August 01, 2019, 03:46:35 pmNo, it's not needed.Which instrument did you use to measure 14.75MHz?In fact you should have this frequency on both pin1 and pin 4 of Y101.

author: letron77
author_rank: Contributor
timestamp: August 01, 2019, 06:55:51 pm
content: These are the two "HU156 and U157"" that were in the device when I bought it.I extracted them from their support in order to save the data they contained With TL866 then i have replaced them.I will quickly buy two AT27C020 to record the firmwaire you sent meRegarding the measurement I have a small digital oscilloscope connected to a laptopI just rechecked the measurements on the Y101:I have 14.75 Mhz on the PIN1 but actually also 14.75 Mhz on the PIN4 (nothing on the other PIN)

author: picburner
author_rank: Frequent Contributor
timestamp: August 01, 2019, 07:20:59 pm
content: I asked you about the two eproms just to know the history of the instrument.I saw that one has the label while the other didn't, there was also the possibility that someone had already removed them or altering the firmware or inverted odd with even but I saw that, at least from what is written on, they are in the right place.By putting the most recent firmware it could happen that it erases the calibration data contained in U136.But if with this new firmware the instrument works then you can search for the original B15 firmware and reload the U136 backup you saved with the the original calibration.I hope the failure is in the firmware and not in the SRAM U151 and U152 because they are more annoying to replace.In my Keithley 2306 a sram just broke and produced the same symptom as your dmm:https://www.eevblog.com/forum/repair/keithley-2306-dual-psu-battery-simulator-repair/msg632229/#msg632229

author: letron77
author_rank: Contributor
timestamp: August 02, 2019, 07:38:49 am
content: Can you tell me if these ICs are correcthttps://www.ebay.fr/itm/Microchip-AT27C020-90JU-OTP-EPROM-Memory-2Mbit-256K-x-8-bit-90ns-32-Pin-PLCC/163124045957?hash=item25faf36885:g:-wgAAOSwjdpbNlN0

author: picburner
author_rank: Frequent Contributor
timestamp: August 02, 2019, 09:21:13 am
content: Yes, they are fine but they are OTP (One Time Programmable).Perhaps it is better that you buy AT49F020 that are re-programmable Flash memories, in case of errors or second thoughts you don't throw them in the trash.