Tektronix 2465B startup error

[JVG]

Hello!

I have got a Tek 2465B which displays this error on startup:

TEST 04 FAIL 11

PUSH A/B TTRIG TO EXIT

From the Service Manual, it seems a calibration data error. Does it
mean there is some faulty non-volatile RAM?. If so, is it replaceable
with a current type?. Any hint to fix this?

Thanks for any help!

Regards,

JOSE
http://jvgavila.com

 

[Jim Yanik]

Hello!

I have got a Tek 2465B which displays this error on startup:

TEST 04 FAIL 11

PUSH A/B TTRIG TO EXIT

From the Service Manual, it seems a calibration data error. Does it
mean there is some faulty non-volatile RAM?. If so, is it replaceable
with a current type?. Any hint to fix this?

Thanks for any help!

Regards,

JOSE
http://jvgavila.com

there's an IC called a NVRAM that stores the cal constants,and it fails
often enough. you have to re-cal the scope after replacement.
I have no idea if there's a modern substitute with a longer life.

 

[Howard Long]

Hello!

I have got a Tek 2465B which displays this error on startup:

TEST 04 FAIL 11

PUSH A/B TTRIG TO EXIT

From the Service Manual, it seems a calibration data error. Does it
mean there is some faulty non-volatile RAM?. If so, is it replaceable
with a current type?. Any hint to fix this?

I have very recently repaired my 2465B and successfully replaced the lithium
battery with a pair of AA's in a battery holder stuck to the PCB with some
double-sided foam adhesive tape. I used decent AA's (Duracell Ultra) in an
attempt to reduce risk of leakage.

Recalibration takes quite some time afterwards, so be prepared!

Cheers, Howard

 

[JVG]

Hello Jim,

Thanks for your answer!

there's an IC called a NVRAM that stores the cal constants,and it fails
often enough. you have to re-cal the scope after replacement.
I have no idea if there's a modern substitute with a longer life.

OK, I have found there are still some compatible ICs I can use (as the
Dallas DS-1225AB-70)

Now, next problem... calibration. What equipment would I need to do
it?

Regards,

JOSE
http://jvgavila.com

 

[JVG]

Hello Howard,

Thanks for your message!

I have very recently repaired my 2465B and successfully replaced the lithium
battery with a pair of AA's in a battery holder stuck to the PCB with some
double-sided foam adhesive tape. I used decent AA's (Duracell Ultra) in an
attempt to reduce risk of leakage.

Recalibration takes quite some time afterwards, so be prepared!

Could you elaborate a bit about that?. Which equipment is needed?. I
have a good lab at home but perhaps not for calibration purposes.

Best regards,

JOSE
http://jvgavila.com

 

[Howard Long]

Hello Howard,

Thanks for your message!



Could you elaborate a bit about that?. Which equipment is needed?. I
have a good lab at home but perhaps not for calibration purposes.

The cal procedure, including the equipment needed is in the service manual.
They discuss the use of a pulse/mark generator, although I used a standard
signal generator with a variable duty cycle and a couple of attenuators for
2MHz and less, and an RF sig gen for the small number of higher frequency
measurements: maybe not the most accurate, but with careful use you can
still do a pretty good cal. The levels were calibrated with another 'scope
in circuit.

The service manual is available at http://bama.sbc.edu/.

One tiny correction - I actually used AAA's not AA's.

Cheers, Howard

 

[JVG]

Hi Howard,

Thanks a lot for your detailed message!. Yes, I will look at the
Service Manual (had it downloaded but was curious to know if it could
be done with the equipment I have... it seems so )

The cal procedure, including the equipment needed is in the service manual.
They discuss the use of a pulse/mark generator, although I used a standard
signal generator with a variable duty cycle and a couple of attenuators for
2MHz and less, and an RF sig gen for the small number of higher frequency
measurements: maybe not the most accurate, but with careful use you can
still do a pretty good cal. The levels were calibrated with another 'scope
in circuit.

One further question... when scope is uncalibrated, does it show a
trace?. On mine, I get only text display with ??? after it.

What I get after the error display and pressing "A/B Trig" is more or
less:

Volt/division ????? SEC/DIV ?????

But no trace... is this usual?

Thanks!

JOSE
http://jvgavila.com

 

[Howard Long]

One further question... when scope is uncalibrated, does it show a
trace?. On mine, I get only text display with ??? after it.

What I get after the error display and pressing "A/B Trig" is more or
less:

Volt/division ????? SEC/DIV ?????

But no trace... is this usual?

Losing the trace was exactly what mine did until I replaced the batteries
and re-cal'd it.

First check it's triggering - the TRIG'D LED should be on.

Your channel (eg, CH1) should be selected.

Try adjusting INTENSITY and the vertical POSITION for your channel.

If no luck, push the BEAM FIND.

If still no luck, press STEP/AUTO.

Still no luck?

Do a DC balance by pushing the upper and lower input coupling buttons for
your channel simultaneously (P4-3 in the operator's manual)., then repeat
the above.

I used to have to go through this each time I switched it on before
replacing the battery and re-cal'ing.

I still have the ?????? on the lower display I believe because I have not
managed to complete the calibration for the option 06 counter timer trigger
module I have installed in my 'scope. I have left the 'scope in CAL mode, so
that the "?????" become less annoying "......" instead for now until I can
figure out the cal procedure for the CT option.

Cheers, Howard

 

[JVG]

Hello Howard,

Thanks for your interesting message!. I will try that ASAP.

But perhaps I can help you on this:

I still have the ?????? on the lower display I believe because I have not
managed to complete the calibration for the option 06 counter timer trigger
module I have installed in my 'scope. I have left the 'scope in CAL mode, so
that the "?????" become less annoying "......" instead for now until I can
figure out the cal procedure for the CT option.

I had some information stored in my PC for 'future use'... and here is
the future !

I hope Jim W8ZR doesn't care for forwarding this information, as he
sent it to help other people with similar troubles.


From the TekScopes Yahoogroup:

=================

Gang,

I thought I'd pass on some notes on calibrating my "new" 2465B, which
is now freshly aligned and running perfectly. I owe Denis Cobley a
huge debt of gratitude for walking me through some stumbling blocks.

Hope these notes can spare some other owners some of the frustration I
experienced.

Here is the problem I experienced:

Before calibration, I was getting an ERROR 04 02 message at powerup,
signifiying that one or more stored calibration constants was out of
spec.

Using a time mark and calibration generator, I stepped throught CAL
01 (horizontal calibration) and CAL 02 (vertical calibration). At a
few of the steps, I got a LIMIT error, and had to back up a step and
redo it..

After I finished, I powered up the scope but still got the ERROR 04
02 message. I redid the entire calibration, but still couldn't get
rid of the error message.

Also, the display showed a row of dots along the bottom line of the
readout, where spaces were supposed to be. WHen I moved the
calibration jumper back to its normal position, the dots turned into
question marks.

Here's what I learned. The service manual doesn't say this, but none
of the calibration constants are stored until the entire calibration
routine (e.g., CAL 01, CAL 02, etc.) is completed and exited. In other
words, if only some of the steps are completed and then the user exits
the calibration routine, none of the new constants are saved..

Second, if a LIMIT error is encountered somewhere during the
calibration, then the new constants won't be stored. The only solution
is to exit the routine and start over.

Finallly (and this is what was causing my problem), there are three
undocumented steps in the CAL 01 procedure. The service manual shows
31 steps for CAL 01, but the 2465B actually has 34 steps. After
completeing the 31 steps, it is necessary to advance through 32, 33,
and 34, and then let the scope exit the routine by itself. If you
don't do this, none of the calibration constants will be stored.

After completing the entire calibration in this way, the dots and
question marks disappeared, as did the startup error message, and all
is as it should be.

Regards,

Jim Garland W8ZR


===============

Thanks again, Jim!

Best regards,

JOSE
http://jvgavila.com

 

[Andreas Tekman]

Hello Howard,

Thanks for your interesting message!. I will try that ASAP.

But perhaps I can help you on this:



I had some information stored in my PC for 'future use'... and here is
the future !

I hope Jim W8ZR doesn't care for forwarding this information, as he
sent it to help other people with similar troubles.

From the TekScopes Yahoogroup:

=================

Gang,

I thought I'd pass on some notes on calibrating my "new" 2465B, which
is now freshly aligned and running perfectly. I owe Denis Cobley a
huge debt of gratitude for walking me through some stumbling blocks.

Hope these notes can spare some other owners some of the frustration I
experienced.

Here is the problem I experienced:

Before calibration, I was getting an ERROR 04 02 message at powerup,
signifiying that one or more stored calibration constants was out of
spec.

Using a time mark and calibration generator, I stepped throught CAL
01 (horizontal calibration) and CAL 02 (vertical calibration).  At a
few of the steps, I got a LIMIT error, and had to back up a step and
redo it..

After I finished, I powered up the scope but still got the ERROR 04
02 message.  I redid the entire calibration, but still couldn't get
rid of the error message.

Also, the display showed a row of dots along the bottom line of the
readout, where spaces were supposed to be.  WHen I moved the
calibration jumper back to its normal position, the dots turned into
question marks.

Here's what I learned.  The service manual doesn't say this, but none
of the calibration constants are stored until the entire calibration
routine (e.g., CAL 01, CAL 02, etc.) is completed and exited. In other
words, if only some of the steps are completed and then the user exits
the calibration routine, none of the new constants are saved..

Second, if a LIMIT error is encountered somewhere during the
calibration, then the new constants won't be stored. The only solution
is to exit the routine and start over.

Finallly (and this is what was causing my problem), there are three
undocumented steps in the CAL 01 procedure.  The service manual shows
31 steps for CAL 01, but the 2465B actually has 34 steps. After
completeing the 31 steps, it is necessary to advance through 32, 33,
and 34, and then let the scope exit the routine by itself. If you
don't do this, none of the calibration constants will be stored.

After completing the entire calibration in this way,  the dots and
question marks disappeared, as did the startup error message, and all
is as it should be.

Regards,

Jim Garland W8ZR

===============

Thanks again, Jim!

Best regards,

JOSEhttp://jvgavila.com

So give the scope and description a place on your "projects webpage".
It is a nice 2465B, a good buy for 333 euros. Congratulations!


cu,
Andreas

 

[dan]

Losing the trace was exactly what mine did until I replaced the batteries
and re-cal'd it.

First check it's triggering - the TRIG'D LED should be on.

Your channel (eg, CH1) should be selected.

Try adjusting INTENSITY and the vertical POSITION for your channel.

If no luck, push the BEAM FIND.

If still no luck, press STEP/AUTO.

Still no luck?

Do a DC balance by pushing the upper and lower input coupling buttons for
your channel simultaneously (P4-3 in the operator's manual)., then repeat
the above.

I used to have to go through this each time I switched it on before
replacing the battery and re-cal'ing.

I still have the ?????? on the lower display I believe because I have not
managed to complete the calibration for the option 06 counter timer trigger
module I have installed in my 'scope. I have left the 'scope in CAL mode, so
that the "?????" become less annoying "......" instead for now until I can
figure out the cal procedure for the CT option.

Cheers, Howard

The CT option is tough, you need a pulse generator FG5010 or PG508 you
can sync to a time mark generator TG501. I like the FG5010 with the
TG501 going into the Trig Gate input with phase lock selected. My
FG5010 is not working now but feel free to get in touch with me in a
month or so at [email protected] I am in SE Portland