tek 2712 freezes during startup


 

Hi,
I have just bought this instrument at Ebay for a reasonable price.
Auction was "as is" but the pictures showed a "working" instrument.
However when it arrived, it would finish the startup sequence.
It "freezes" in the "file cleanup" and does not respond to any button press.
Three leds are on: res bw auto, sweep auto and "D".
I have not opened yet to check if something was loosened during shipping, but I would like to have an idea of what (or where to look) before I start.
I will add a photo of the screen and the the
Any ideas/comments will be highly appreciated.
Thanks,

Roger


Glenn Little
 

I do not have a 2712 nor do I have a manual.
I would suspect that there is an issue with the processor.
I would check any batteries in the instrument and replace dead or dying
ones.
I would ensure that any socketed chips are firmly in the socket.
I would ensure that all interconnecting cables are firmly seated.
It sounds like the processor gets to a point in the boot sequence and hangs.
I would get the service manual and check all supply voltages for voltage
and ripple.

http://w140.com/tekwiki/wiki/2712  has the user manual.
This might point you in the right direction.

The service manual is here
https://www.tek.com/manual/2711-2712-service-manual

Glenn
On 10/28/2017 12:20 PM, rodd@globo.com [TekScopes] wrote:

Hi,
I have just bought this instrument at Ebay for a reasonable price.
Auction was "as is" but the pictures showed a "working" instrument.
However when it arrived, it would finish the startup sequence.
It "freezes" in the "file cleanup" and does not respond to any button
press.
Three leds are on: res bw auto, sweep auto and "D".
I have not opened yet to check if something was loosened during
shipping, but I would like to have an idea of what (or where to look)
before I start.
I will add a photo of the screen and the the
Any ideas/comments will be highly appreciated.
Thanks,

Roger





--
-----------------------------------------------------------------------
Glenn Little ETCS(SS) USN Ret, ARRL Technical Specialist, SBE ARRL TAPR
Amateur Callsign: WB4UIV wb4uiv@arrl.net AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI, FRA, NRA LM QCWA LM 28417
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"
---------------------------------------------------------------------------


Jokken Feldhaar
 

Hi Roger,

I think I had a 2710 with a similar problem. It turned out that the 100
MHz TCXO was not working, maybe you should check this out. Good Luck!

Regards, Jochen DH6FAZ


Am 28.10.2017 um 18:20 schrieb rodd@globo.com [TekScopes]:

Hi,
I have just bought this instrument at Ebay for a reasonable price.
Auction was "as is" but the pictures showed a "working" instrument.
However when it arrived, it would finish the startup sequence.
It "freezes" in the "file cleanup" and does not respond to any button
press.
Three leds are on: res bw auto, sweep auto and "D".
I have not opened yet to check if something was loosened during
shipping, but I would like to have an idea of what (or where to look)
before I start.
I will add a photo of the screen and the the
Any ideas/comments will be highly appreciated.
Thanks,

Roger



[Non-text portions of this message have been removed]



[Non-text portions of this message have been removed]


 

Hi Glenn,
Thank you for your reply
I opened the instrument and verified that one battery is dead and the other almost gone. Is there any recommendation on how to change them?
Do I have to solder a "temporary backup battery" in parallel before I start to dessolder the original battery?
Thanks


Glenn Little
 

I would download the service manual and see what it has to say.

If it were me, I would use a temporary backup battery unless I knew it
was not needed.

Glenn

On 10/28/2017 8:15 PM, rodd@globo.com [TekScopes] wrote:

Hi Glenn,
Thank you for your reply
I opened the instrument and verified that one battery is dead and the
other almost gone. Is there any recommendation on how to change them?
Do I have to solder a "temporary backup battery" in parallel before I
start to dessolder the original battery?
Thanks



--
-----------------------------------------------------------------------
Glenn Little ETCS(SS) USN Ret, ARRL Technical Specialist, SBE ARRL TAPR
Amateur Callsign: WB4UIV wb4uiv@arrl.net AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI, FRA, NRA LM QCWA LM 28417
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"
---------------------------------------------------------------------------


Chuck Harris <cfharris@...>
 

The 2712 has the ability to calibrate itself, so there
is no need to worry when changing the batteries... just
change them, and press the auto calibrate button.

-Chuck Harris

rodd@globo.com [TekScopes] wrote:

Hi Glenn,
Thank you for your reply
I opened the instrument and verified that one battery is dead and the other almost gone. Is there any recommendation on how to change them?
Do I have to solder a "temporary backup battery" in parallel before I start to dessolder the original battery?
Thanks


Sergey Kubushyn
 

On Sat, 29 Oct 2017, rodd@globo.com [TekScopes] wrote:

There is nothing critical in those battery backed RAMs in 2712. All hardware
calibration ("Adjustments") is by trimpots/trimcaps so it is not affected by
the battery. Software calibration is fully automated and performed by 2712
at any time. You might need a reference signal for that (don't remember if
it is 10MHz or 100MHz) but it is nothing to write home about. Just start
calibration ("normalization"?) from menu, apply reference signal when
prompted and you will get all the normalization constants properly setup in
RAM. It works even with totally dead batteries, just has to be done every
time the instrument powers up. With good batteries those normalization
constants persist between powerups so you won't have to do normalization
every time you turn your 2712 on. You have to do normalization from time to
time even with good batteries to eliminate all kinds of accumulated drift
anyway.

Hi Glenn,
Thank you for your reply
I opened the instrument and verified that one battery is dead and the
other almost gone. Is there any recommendation on how to change them? Do
I have to solder a "temporary backup battery" in parallel before I start
to dessolder the original battery?
Thanks
---
******************************************************************
* KSI@home KOI8 Net < > The impossible we do immediately. *
* Las Vegas NV, USA < > Miracles require 24-hour notice. *
******************************************************************


Jeff Woolsey
 

On 10/28/17 9:02 PM, Sergey Kubushyn ksi@koi8.net [TekScopes] wrote:
 

On Sat, 29 Oct 2017, rodd@globo.com [TekScopes] wrote:

There is nothing critical in those battery backed RAMs in 2712. All
hardware
calibration ("Adjustments") is by trimpots/trimcaps so it is not
affected by
the battery. Software calibration is fully automated and performed by 2712
at any time. You might need a reference signal for that (don't remember if
it is 10MHz or 100MHz) but it is nothing to write home about.
It nominally wants 100MHz, but you can use pretty much any reliable
signal since you can enter its frequency.  I used a 10MHz GPSDO on my
2715.   Note that this does not adjust the calibrator frequency as it's
more important that that be stable than accurate.  Expect a few hundred
Hz difference.  Instead it adjusts the counter timebase.

I believe there are also setups in that RAM.  My user setup turns off
the CATV stuff.  The weird realtime clock is probably in there, too.

A friend's 2712 needs new batteries since I couldn't make my adjustments
stick.

--
Jeff Woolsey {{woolsey,jlw}@jlw,first.last@{gmail,jlw}}.com
Nature abhors straight antennas, clean lenses, and empty storage.
"Delete! Delete! OK!" -Dr. Bronner on disk space management
Card-sorting, Joel. -Crow on solitaire



[Non-text portions of this message have been removed]


Sergey Kubushyn
 

On Sun, 29 Oct 2017, Jeff Woolsey jlw@jlw.com [TekScopes] wrote:

On 10/28/17 9:02 PM, Sergey Kubushyn ksi@koi8.net [TekScopes] wrote:
 

On Sat, 29 Oct 2017, rodd@globo.com [TekScopes] wrote:

There is nothing critical in those battery backed RAMs in 2712. All
hardware
calibration ("Adjustments") is by trimpots/trimcaps so it is not
affected by
the battery. Software calibration is fully automated and performed by 2712
at any time. You might need a reference signal for that (don't remember if
it is 10MHz or 100MHz) but it is nothing to write home about.
It nominally wants 100MHz, but you can use pretty much any reliable
signal since you can enter its frequency.  I used a 10MHz GPSDO on my
2715.   Note that this does not adjust the calibrator frequency as it's
more important that that be stable than accurate.  Expect a few hundred
Hz difference.  Instead it adjusts the counter timebase.

I believe there are also setups in that RAM.  My user setup turns off
the CATV stuff.  The weird realtime clock is probably in there, too.
Setups yes, but those are not critical and can be redone at any time.

---
******************************************************************
* KSI@home KOI8 Net < > The impossible we do immediately. *
* Las Vegas NV, USA < > Miracles require 24-hour notice. *
******************************************************************

[Non-text portions of this message have been removed]


 

Hi folks, Thank you all for the information.
I have already ordered the replacements and will post the results as soon as I change them.
Regards,
Roger


 

Hi, I have replaced the batteries but the SA freezes at the same point.
I was hoping that I would find a loose connection or similar issue since it is a long way from US to Brazil, and it was "in working condition" when I bought it (with photos).
Unfortunately that was not the case.
I wonder if the problem is related to the front panel since the last line of the error screen says "press W to cont; Z to abort" but I have tried every key and nothing happens.
Is it possible to know if the problem is really a freeze during boot or a defective front panel?
Any other ideas?
The link to the error screen and the lighted leds of the front panel is attached below.
https://groups.yahoo.com/neo/groups/TekScopes/photos/photostream/lightbox/191654049?orderBy=mtime&;sortOrder=desc&amp;photoFilter=ALL#zax/2075059146 https://groups.yahoo.com/neo/groups/TekScopes/photos/photostream/lightbox/191654049?orderBy=mtime&;sortOrder=desc&amp;photoFilter=ALL#zax/2075059146


ti8jlh
 

El 08/11/2017 a las 05:50 p.m., rodd@globo.com [TekScopes] escribió:


Hi, I have replaced the batteries but the SA freezes at the same point.
I was hoping that I would find a loose connection or similar issue
since it is a long way from US to Brazil, and it was "in working
condition" when I bought it (with photos).
Unfortunately that was not the case.
I wonder if the problem is related to the front panel since the last
line of the error screen says "press W to cont; Z to abort" but I have
tried every key and nothing happens.
Is it possible to know if the problem is really a freeze during boot
or a defective front panel?
Any other ideas?
The link to the error screen and the lighted leds of the front panel
is attached below.
https://groups.yahoo.com/neo/groups/TekScopes/photos/photostream/lightbox/191654049?orderBy=mtime&sortOrder=desc&photoFilter=ALL#zax/2075059146
https://groups.yahoo.com/neo/groups/TekScopes/photos/photostream/lightbox/191654049?orderBy=mtime&sortOrder=desc&photoFilter=ALL#zax/2075059146



[Non-text portions of this message have been removed]


ti8jlh
 

El 08/11/2017 a las 05:50 p.m., rodd@globo.com [TekScopes] escribió:

Hi, I have replaced the batteries but the SA freezes at the same point.
I was hoping that I would find a loose connection or similar issue
since it is a long way from US to Brazil, and it was "in working
condition" when I bought it (with photos).
Unfortunately that was not the case.
I wonder if the problem is related to the front panel since the last
line of the error screen says "press W to cont; Z to abort" but I have
tried every key and nothing happens.
Is it possible to know if the problem is really a freeze during boot
or a defective front panel?
Any other ideas?
The link to the error screen and the lighted leds of the front panel
is attached below.
https://groups.yahoo.com/neo/groups/TekScopes/photos/photostream/lightbox/191654049?orderBy=mtime&sortOrder=desc&photoFilter=ALL#zax/2075059146
https://groups.yahoo.com/neo/groups/TekScopes/photos/photostream/lightbox/191654049?orderBy=mtime&sortOrder=desc&photoFilter=ALL#zax/2075059146



[Non-text portions of this message have been removed]

Hello Roger, I forgot to ask you if you looked at the 100 Mhz TXCO as
Jochen wrote?
I will try to do that tomorrow.
Joachim


[Non-text portions of this message have been removed]


Chuck Harris <cfharris@...>
 

Have each of you looked into the condition of the SMD electrolytic
capacitors on your spectrum analyzers?

In the few examples of these spectrum analyzers that I have worked
on, I have found a number of problems:

1) focus string SMD 1M and 2M resistors that weren't properly
soldered due to a plating failure on the board.
2) a whole slew of SMD electrolytic capacitors that were leaking
electrolyte.
3) dead lithium cells used for memory functions...
4) switching power supply capacitors that are high ESR.

If any of the solder joints around the SMD electrolytic capacitors
are milky white in color, rather than shiny and metallic, the
capacitors are leaking electrolyte.

-Chuck Harris

Joachim Lange ti8jlh@gmail.com [TekScopes] wrote:

El 08/11/2017 a las 05:50 p.m., rodd@globo.com [TekScopes] escribi�:

Hi, I have replaced the batteries but the SA freezes at the same point.
I was hoping that I would find a loose connection or similar issue
since it is a long way from US to Brazil, and it was "in working
condition" when I bought it (with photos).
Unfortunately that was not the case.
I wonder if the problem is related to the front panel since the last
line of the error screen says "press W to cont; Z to abort" but I have
tried every key and nothing happens.
Is it possible to know if the problem is really a freeze during boot
or a defective front panel?
Any other ideas?
The link to the error screen and the lighted leds of the front panel
is attached below.
https://groups.yahoo.com/neo/groups/TekScopes/photos/photostream/lightbox/191654049?orderBy=mtime&sortOrder=desc&photoFilter=ALL#zax/2075059146
https://groups.yahoo.com/neo/groups/TekScopes/photos/photostream/lightbox/191654049?orderBy=mtime&sortOrder=desc&photoFilter=ALL#zax/2075059146





Hello Roger, I forgot to ask you if you looked at the 100 Mhz TXCO as
Jochen wrote?
I will try to do that tomorrow.
Joachim






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Yahoo Groups Links




 

Hi, Does anyone have an idea if the "file system cleanup" is part of the normal startup sequence?
If not, what may be causing this behaviour.
Thanks


Chuck Harris <cfharris@...>
 

It is a normal part of the startup sequence, if the
CMOS RAM's contents is corrupted, which usually means
the lithium cell is bad.

For whatever reason, the 2710. 2711, and 2712, do not
flush the RAM and automatically start over if the RAM
is corrupted. Instead, they give a warning message,
quit start up, and expect you to do the deed.

-Chuck Harris

rodd@globo.com [TekScopes] wrote:

Hi, Does anyone have an idea if the "file system cleanup" is part of the normal startup sequence?
If not, what may be causing this behaviour.
Thanks






------------------------------------
Posted by: rodd@globo.com
------------------------------------


Sergey Kubushyn
 

On Fri, 10 Nov 2017, rodd@globo.com [TekScopes] wrote:

Hi, Does anyone have an idea if the "file system cleanup" is part of the
normal startup sequence?
If not, what may be causing this behaviour.
That means your battery is dead. It should not freeze the system anyway.
Will be executed on each and every boot until you replace the battery.

---
******************************************************************
* KSI@home KOI8 Net < > The impossible we do immediately. *
* Las Vegas NV, USA < > Miracles require 24-hour notice. *
******************************************************************


 

This means I have other problems since I have replaced the two batteries. There were signs of corrosion around some smd resistors.
I have cleaned the board with IPA and the traces and pads "appeared" to be OK, but I have not checked for continuity.
I will take a closer look now and post the results.
By the way, how many layers are there in these boards?
There are some via points close to some of these resistors...


Chuck Harris <cfharris@...>
 

IPA doesn't do a good job of cleaning up electrolyte.

The 70% IPA would be better than the 99% IPA, but
something water based would be best of all...

Electrolyte is water soluble.

-Chuck Harris

rodd@globo.com [TekScopes] wrote:

This means I have other problems since I have replaced the two batteries. There were signs of corrosion around some smd resistors.
I have cleaned the board with IPA and the traces and pads "appeared" to be OK, but I have not checked for continuity.
I will take a closer look now and post the results.
By the way, how many layers are there in these boards?
There are some via points close to some of these resistors...




Sergey Kubushyn
 

On Fri, 10 Nov 2017, Chuck Harris cfharris@erols.com [TekScopes] wrote:

It is also alkaline so it is better to neutralize it so it would make less
harm even if not washed completely.

Weak formic acid solution (kinda like 5% or so) is very effective. It also
evaporates cleanly al formic acid is more volatile than water.

Yet another feature of formic acid is that it clearly marks alcali affected
solder joints. It does nothing when applied to a good, uncorroded solder
joint but those affected by electrolyte turn dark grey or even black on
contact so you clearly see what joints need to be reworked.

I do usually replace the components at those corroded joints if I have them
in stock but that is not strictly necessary.

BTW, there are another ticking time bombs in many Tek/HP instruments, wet
tantalums. Those almost always fail after 20 years or so and they are very
nasty. Unlike regular electrolytic capacitors with alkaline electrolyte wet
tantalums have liquid sulfuric acid inside that makes quite a mess. Such
messes need alcaline neutralizer, not formic acid. Ammonia solution is the
best treatment but it has very strong odor.

Some of Tek gear is more prone to capacitor failures that other. I've
recently finished refurbishing one 492BP and three 494AP instruments
[keeping one 494AP for myself; the rest will be put on eBay once I have the
horror refurbishing story with lots of pictures ready to include it into
descriptions so people actually see what REAL refurbishing means] and it was
the worst nightmare of all I ever seen. ALL power supply capacitors were
bad, every single one in all 4 instruments. Lots of SMD electrolytics
everywhere including inside tightly enclosed RF parts, ALL of them leaked
with severe damage to PCBs. Lots of wet tantalums, almost all of them etched
through with horrible sulfuric acid induced damage around. If a trimpot was
nearby it got damaged by this and required replacement.

There were more ticking time bombs in those 492BP/494AP instruments. Most
prominent were trimcaps with polypropylene insulation. Those are present in
3 modules -- VR, deflection amp, and 100/10Hz filter (the latter in 494AP
only.) That PP film simply disintegrates and fells off so capacitance drops,
instrument gets out of adjustment and it is impossible to adjust it because
those trimcaps short theirselves on a slightest touch. Some of foil is still
in place, some is not attached any more to the trimcap shaft so it moves
thus making the instrument adjustment changing when it is moved. The worst
of them all is 100/10Hz filter in 494AP. It runs very hot, almost at maximum
temperature those trimcaps are rated at so they disintegrate much faster and
almost always require replacement. And they are not all that cheap,
something like $6 apiece :(

BTW, some of 492/494xy[P] instruments have older SMD electrolytics predating
those leaky aluminum cans. Those look like SMD solid tantalums but are
usually thicker and always black. Those are NOT tantalums and surprisinly I
have never seen even a single failed one so if one is lucky to have those
instead of aluminum cans he don't need to replace them.

And there are also film resistors that go open without ANY visual indication
of failure, even when closely inspected under microscope. Not even a
slightest discoloration but totally open, no continuity. Off of 4
instruments 2 had their Z-Axis board failed because of those higher power
film resistors.

IPA doesn't do a good job of cleaning up electrolyte.

The 70% IPA would be better than the 99% IPA, but
something water based would be best of all...

Electrolyte is water soluble.

-Chuck Harris

rodd@globo.com [TekScopes] wrote:
This means I have other problems since I have replaced the two batteries. There were signs of corrosion around some smd resistors.
I have cleaned the board with IPA and the traces and pads "appeared" to be OK, but I have not checked for continuity.
I will take a closer look now and post the results.
By the way, how many layers are there in these boards?
There are some via points close to some of these resistors...
---
******************************************************************
* KSI@home KOI8 Net < > The impossible we do immediately. *
* Las Vegas NV, USA < > Miracles require 24-hour notice. *
******************************************************************