EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: Jay_Diddy_B on February 10, 2014, 10:57:46 pm
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Hi group,
I am looking for a nice, readable, schematic for the Keithley 177 DMM.
I have found the one on the Keithley website that is complete, but barely readable.
I found another one which was very readable, but only half the schematic.
I have one of these for repair.
Many thanks !!
Jay_Diddy_B
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Register at keithley.com and download it from there?
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Wiss,
Thank you for the reply. I have registered with Keithley and downloaded the manual. This is where I got the one with unreadable schematics. The file size is 2740kB (according to Windows).
Here is a sample of the schematic:
(https://www.eevblog.com/forum/testgear/looking-for-keithley-177-dmm-schematic/?action=dlattach;attach=80812;image)
Thanks,
Jay_Diddy_B
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Sorry, a bit quick to reply...
You only need the scematics? I can see if there are any at work...
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I did find a 177 so there is a reasonably high probability that the manual is somewhere in the building, the person responsible for it is not here until Thursday, I`ll ask then.
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No luck :(
It might be somewhere but it will take a large amount of time to locate it...
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Wiss,
Thank you very much for your efforts.
I will try and fix the meter with the schematic in the manual that I have.
Jay_Diddy_B
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I had exactly the same problem trying to fix my Keithley 177 and building a RS232 interface for it. I ended up with trying to recreate the schematics and after many hours I got what I suspect is a accurate redraw.
Hope it helps! I cannot guarantee that every connection I've drawn is correct, but I succeeded both in fixing my DMM and to create a RS232-interface using a AVR.
I hope its not the power supply that is the problem in your case. I redraw almost all BUT the power supply, since it worked ok for me.
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MBY,
Thank you for providing the re-touched schematic. I found a manual here:
http://exodus.poly.edu/~kurt/manuals/manuals/Keithley/KEI%20177%20Instruction.pdf (http://exodus.poly.edu/~kurt/manuals/manuals/Keithley/KEI%20177%20Instruction.pdf)
This manual is little cleaner than the manual from the Keithley website. Unfortunately it contains only half of the schematic. It does include the power supply section. I have attached the pdf with the power supply section.
I have three of these meters that I got in a package deal with a 175, 197 and three 177. None of the working.
All of them, except one of the 177 are repaired.
The two 177 had dirty switches, I cleaned the switches and then cleaned the board. The remaining 177 has a bad ICL71C03, the main chip.
Thank you again!!
Regards,
Jay_Diddy_B
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Just to note that the RACAL DANA 4003 DMM is a rebadged Keithley 177.
On ebay there is a seller 'teoulet' (Tucker electronics) selling manuals and they have currently a listing for the 4003 manual, which in the photo is the main schematic and P/S schematic.
They are actually quite readable so you can "re touch" your crummy copy if any part of it is not readable!!.
Look for 'DANA manual 4003 '!. and see what I mean.
I have a 4003 but alas I do not have the handbook, and also have to get by with the awful copy as well.
EDIT Aug 2018
I did find a 177 manual and have uploaded a decent copy of the schematic and part layout in this thread ;
https://www.eevblog.com/forum/repair/keithley-177-power-supply/ (https://www.eevblog.com/forum/repair/keithley-177-power-supply/)
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Hi,
Here is the schematic picture from the teoutlet listing.
(https://www.eevblog.com/forum/testgear/looking-for-keithley-177-dmm-schematic/?action=dlattach;attach=81819;image)
Regards,
Jay_Diddy_B