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Keithley 197 troubleshooting

D

Dan Lenski

Jan 1, 1970
0
Hi all,
I have a disabled Keithley 197 DMM. This is an older model, but it
has a nice GPIB interface, so I'd like to get it working.

When turned on, it displays the message "cErr". According to the
manual (http://www.tnw.utwente.nl/onderwijs/practica/doc/app/
keithley197.pdf) this means that there's a problem with the NVRAM that
stores the calibration data. I've tried bypassing this error by
pressing the buttons as recommended on page 5-9 of the manual, however
the cErr reappears.

The NVRAM chip is a little 8-pin DIP chip apparently. I'm having
trouble identifying it. It's labeled:

X2443P
8432ES

Anybody know what this chip is, or can give me any other advice in
getting this DMM working? Thanks,

Dan
 
D

DaveM

Jan 1, 1970
0
Dan Lenski said:
Hi all,
I have a disabled Keithley 197 DMM. This is an older model, but it
has a nice GPIB interface, so I'd like to get it working.

When turned on, it displays the message "cErr". According to the
manual (http://www.tnw.utwente.nl/onderwijs/practica/doc/app/
keithley197.pdf) this means that there's a problem with the NVRAM that
stores the calibration data. I've tried bypassing this error by
pressing the buttons as recommended on page 5-9 of the manual, however
the cErr reappears.

The NVRAM chip is a little 8-pin DIP chip apparently. I'm having
trouble identifying it. It's labeled:

X2443P
8432ES

Anybody know what this chip is, or can give me any other advice in
getting this DMM working? Thanks,

Dan

The X2443P is a Xicor NMOS nonvolatile static RAM, 16 bits X 16 words, tristate,
750ns, Vcc = 5V

I searched briefly for anything that would be a good sub for it, but came up
empty. Maybe you can do better.
--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate characters in the
address)

Life is like a roll of toilet paper; the closer to the end, the faster it goes.
 
D

DaveM

Jan 1, 1970
0
DaveM said:
The X2443P is a Xicor NMOS nonvolatile static RAM, 16 bits X 16 words,
tristate, 750ns, Vcc = 5V

I searched briefly for anything that would be a good sub for it, but came up
empty. Maybe you can do better.

I forgot to mention that the X2443 is a serial 16x16 RAM.
I did happen to find one web site that lists the X2443 in stock
(http://www.acecomponents.com/) but no price, so you're at their mercy.

Cheers!!
 
D

Dan Lenski

Jan 1, 1970
0
I forgot to mention that the X2443 is a serial 16x16 RAM.
I did happen to find one web site that lists the X2443 in stock
(http://www.acecomponents.com/) but no price, so you're at their mercy.

Cheers!!

Thank you, Dave! Sounds like it's a pretty obsolete part :) Maybe
someone makes a pin-compatible serial RAM in a larger size?

I think I'll do the other tests on the device to make sure everything
else is working, then try to track down this part.

By the way, how'd you find out what it is? Alldatasheet.com and
Google weren't much help to me.

Dan
 
D

DaveM

Jan 1, 1970
0
Dan Lenski said:
Thank you, Dave! Sounds like it's a pretty obsolete part :) Maybe
someone makes a pin-compatible serial RAM in a larger size?

I think I'll do the other tests on the device to make sure everything
else is working, then try to track down this part.

By the way, how'd you find out what it is? Alldatasheet.com and
Google weren't much help to me.

Dan


I found it at http://www.datasheetarchive.com. That's the only datasheet web
site that even came close, but still no complete datasheet; just a list of basic
specs.
Not even a pinout...

Cheers!!!

--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate characters in the
address)

Life is like a roll of toilet paper; the closer to the end, the faster it goes.
 
I found it athttp://www.datasheetarchive.com. That's the only datasheet web
site that even came close, but still no complete datasheet; just a list of basic
specs.
Not even a pinout...

Cheers!!!

We scanned several Xicor data books for our datasheet site but didn't
realize they were scanned at the wrong resolution. The books were sent
for recycling before we realized. This is one of those scans which
gives some detail on X2443.

It's almost unreadable but here it is anyhow.

http://www.datasheetarchive.com/x2443.pdf
http://www.datasheetarchive.com/x2443.jpg

Regards
DatasheetArchive.com
 
D

DaveM

Jan 1, 1970
0
We scanned several Xicor data books for our datasheet site but didn't
realize they were scanned at the wrong resolution. The books were sent
for recycling before we realized. This is one of those scans which
gives some detail on X2443.

It's almost unreadable but here it is anyhow.

http://www.datasheetarchive.com/x2443.pdf
http://www.datasheetarchive.com/x2443.jpg

Regards
DatasheetArchive.com


Thanks for the follow-up!!! Very kind of you to post those pages. Databooks
going to a recycler!!!!???? ACKKKKKK!!!!!!!!!!!!!!!

--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate characters in the
address)

Life is like a roll of toilet paper; the closer to the end, the faster it goes.
 
C

carneyke

Jan 1, 1970
0
Hi all,
I have a disabled Keithley 197 DMM. This is an older model, but it
has a nice GPIB interface, so I'd like to get it working.

When turned on, it displays the message "cErr". According to the
manual (http://www.tnw.utwente.nl/onderwijs/practica/doc/app/
keithley197.pdf) this means that there's a problem with the NVRAM that
stores the calibration data. I've tried bypassing this error by
pressing the buttons as recommended on page 5-9 of the manual, however
the cErr reappears.

The NVRAM chip is a little 8-pin DIP chip apparently. I'm having
trouble identifying it. It's labeled:

X2443P
8432ES

Anybody know what this chip is, or can give me any other advice in
getting this DMM working? Thanks,

Dan

Perhaps it needs to be calibrated and the error will disappear.
 
D

Dan Lenski

Jan 1, 1970
0
Perhaps it needs to be calibrated and the error will disappear.

Yeah, I've tried to go through the calibration procedure but it won't
go into it... as soon as it begins it puts up the "cErr" message. I
think this means the NVRAM is actually dead, not just blanked.

Dan
 
C

carneyke

Jan 1, 1970
0
Yeah, I've tried to go through the calibration procedure but it won't
go into it... as soon as it begins it puts up the "cErr" message. I
think this means the NVRAM is actually dead, not just blanked.

Dan

Dan,
I still think it needs calibration. Does the unit have a rear panel
cal enable switch or an internal jumper for cal enable. You need a
manual if you don't have one. Keithley website may have a downloadable
version. When you power up and get the "cErr", press one of the soft
keys (rel, db, sto or rcl). That will bypass the error and let it
operate with a flashing "c" indicating cal constants lost. The manual
i have indicates different cal procedures for the different firmware
versions. You need a manual. BTW the soft keys (previously mentioned)
need cleaning or they don't makle contact. Good Luck, Kevin
 
D

Dan Lenski

Jan 1, 1970
0
Dan,
I still think it needs calibration. Does the unit have a rear panel
cal enable switch or an internal jumper for cal enable. You need a
manual if you don't have one. Keithley website may have a downloadable
version. When you power up and get the "cErr", press one of the soft
keys (rel, db, sto or rcl). That will bypass the error and let it
operate with a flashing "c" indicating cal constants lost. The manual
i have indicates different cal procedures for the different firmware
versions. You need a manual. BTW the soft keys (previously mentioned)
need cleaning or they don't makle contact. Good Luck, Kevin

Kevin, thanks for the tips. I do have the manual, and have tried
this. Unfortunately, when I press one of the soft keys it flashes all
zeroes (like when just turned on), and then returns to the cErr
message in about 0.5 seconds.

The manual doesn't say what to do in this case, although it says to
try replacing the NVRAM IC if the cErr persists...

Dan
 
C

carneyke

Jan 1, 1970
0
Kevin, thanks for the tips. I do have the manual, and have tried
this. Unfortunately, when I press one of the soft keys it flashes all
zeroes (like when just turned on), and then returns to the cErr
message in about 0.5 seconds.

The manual doesn't say what to do in this case, although it says to
try replacing the NVRAM IC if the cErr persists...

Dan

Damn it's a good meter too, lots of digits. If you really need it,
Keithley always provided good service at reasonable rates. I don't
know if they will service that model. I have a Keithley 197 on my
bench at work. I keep it for the min-max function to "trap"
intermittent problems. Good Luck, Kevin
 
P

Peter Matler

Jan 1, 1970
0
carneyke said:
Damn it's a good meter too, lots of digits. If you really need it,
Keithley always provided good service at reasonable rates....

And, they do sell parts...
Peter
 
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