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11801 diagnostic help

Reginald Beardsley
 

My 11801 arrived today. On power up it makes two beeps and puts up two lines of text on the screen:

Diagnostics in progress

Comm Test in progress

But does not go past that. The seller sent a picture showing an E5622 error, "passed" below that and ???? for the timebase, main acq, mcu a-d acq entries and a picture of the screen with "Self test in progress".

I have reseated all the boards and cables behind the CRT and the cables on the display board. The display board was missing the 4 corner screws. I have replaced those.

So does anyone recognize the issue? While I was pulling the boards I checked the 4 lithium cells and all were over 3 V despite 1988 date codes. That did not match the service manual for the 11801C which is a little disturbing. Is this really just a CSA803 with 4 extra ADC channels? Does anyone know of a manual for this unit? I think all the ROMs are marked 1989, but was not meticulous about that detail as I expected reseating the connectors to have an effect.

Thanks,
Reg

 

What is the voltage on pin 28 of the two socketed rams on the timing and control board in the bottom of the unit?

On 3/15/2019 4:07 PM, Reginald Beardsley via Groups.Io wrote:
My 11801 arrived today. On power up it makes two beeps and puts up two lines of text on the screen:

Diagnostics in progress

Comm Test in progress

But does not go past that. The seller sent a picture showing an E5622 error, "passed" below that and ???? for the timebase, main acq, mcu a-d acq entries and a picture of the screen with "Self test in progress".

I have reseated all the boards and cables behind the CRT and the cables on the display board. The display board was missing the 4 corner screws. I have replaced those.

So does anyone recognize the issue? While I was pulling the boards I checked the 4 lithium cells and all were over 3 V despite 1988 date codes. That did not match the service manual for the 11801C which is a little disturbing. Is this really just a CSA803 with 4 extra ADC channels? Does anyone know of a manual for this unit? I think all the ROMs are marked 1989, but was not meticulous about that detail as I expected reseating the connectors to have an effect.

Thanks,
Reg


Reginald Beardsley
 

I'm not sure I can identify the board. There are a couple of boards with no markings. I reseated the 4 boards on the left side while checking to see what they are. the left two are a memory board and a memory expansion board. The 3rd board is marked "property of and copyright Silicon Software". It and the other board next to it look very different and have no Tek markings.

I have gotten it to run the self test and it stops in the extended diagnostics with the E5622 error. I'm still hunting for a service manual. The BAMA has an 11801C manual listed as an 11801. There are a couple on eBay and I've asked the sellers to verify that they are for the 11801 and not a later variant. So far not replies.

 

Tek 11801 Timebase Errors
Tektronix 11801, 11802, and CSA803 sampling scopes eventually fail with an
E5622 timebase error.
If you remove the bottom panel, you'll see a cluster of sram chips...
Two of them are plugged into Dallas "smart socket" battery backup things, which
in turn are plugged into the board. Likely the tiny batteries have died.
You can replace the Dallas things, which is the Dallas/Maxim (discontinued!) part
number DS1213. Or you can chuck the rams and the Dallas widgets and plug in
two ST Micro part number M48Z35-70PC1, which is a battery-backed SRAM
module. Digikey has them.
After you do this, you'll need to power cycle two or three times until it works.
There are coin-cell batteries on other boards in the main cardcage, but they
seem to last a long time.
Any other tips on 11801 or sampling head repair would be appreciated. Tek
never published schematics or other service info beyond board swapping.
The eeprom chips in the sampling heads seem to fail fairly often, and it would be
interesting to find a way to replace them.
John Larkin Highland Technology Inc jjlarkin@...

On 3/15/2019 5:51 PM, Reginald Beardsley via Groups.Io wrote:
I'm not sure I can identify the board. There are a couple of boards with no markings. I reseated the 4 boards on the left side while checking to see what they are. the left two are a memory board and a memory expansion board. The 3rd board is marked "property of and copyright Silicon Software". It and the other board next to it look very different and have no Tek markings.

I have gotten it to run the self test and it stops in the extended diagnostics with the E5622 error. I'm still hunting for a service manual. The BAMA has an 11801C manual listed as an 11801. There are a couple on eBay and I've asked the sellers to verify that they are for the 11801 and not a later variant. So far not replies.


Reginald Beardsley
 

No one in the US will have the ST part in stock until June! But someone in the UK has offered to get a couple for me there.

I bought the scope for $100 plus $85 shipping because I knew what the E5622 error was. And I dealt with replacing the Dallas part in a Sun workstation.

Reseating all the connectors a 2nd time seems to have done the trick and I can navigate around the extended diagnostics with the touch screen. I got a pair of SD-22s for $150 and an extension cable for $100, so if the SD-22s are OK or are repairable I'll have it up and running for less than $500 which is pretty cool. The screen is clean and crisp. No burn.

I still want to get a complete set of manuals for the 11801, but so far the 11801A version is as close as I can get. I do wish people would label things properly. Once I get proper manuals I'll scan them and send them to all the archives.

I'm really not sure what I have yet. I've got 6 cards in the bay behind the CRT, but I was not able to learn anything about the memory expansion board from the diagnostic screen.

Have Fun!
Reg

Jim Ford
 

I'm envious of your scores!  Some day I will get back into owning and operating 11000 series gear....Jim Ford Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------From: "Reginald Beardsley via Groups.Io" <pulaskite=yahoo.com@groups.io> Date: 3/15/19 3:48 PM (GMT-08:00) To: TekScopes@groups.io Subject: Re: [TekScopes] 11801 diagnostic help No one in the US will have the ST part in stock until June!  But someone in the UK has offered to get a couple for me there.  I bought the scope for $100 plus $85 shipping because I knew what the E5622 error was.  And I dealt with replacing the Dallas part in a Sun workstation.Reseating all the connectors a 2nd time seems to have done the trick and I can navigate around the extended diagnostics with the touch screen.  I got a pair of SD-22s for $150 and an extension cable for $100, so if the SD-22s are OK or are repairable I'll have it up and running for less than $500 which is pretty cool. The screen is clean and crisp.  No burn.I still want to get a complete set of manuals for the 11801, but so far the 11801A version is as close as I can get.  I do wish people would label things properly.  Once I get proper manuals I'll scan them and send them to all the archives.I'm really not sure what I have yet.  I've got 6 cards in the bay behind the CRT, but I was not able to learn anything about the memory expansion board from the diagnostic screen.Have Fun!Reg

Reginald Beardsley
 

Be careful what you wish for. Now I need to build a pulse generator with a fast enough edge to test it.

I am still a bit amazed I was so lucky. though for a couple of hours I was going, " What have I got myself into?" I bought it on the assumption it would be a fairly easy repair.

I tried to build a fast edge pulser using a clock chip and the fastest logic I could get 25 years ago. I thought at the time I had failed miserably, but I tested the units recently and found that the apparent failure was because the EE at work who was helping me test it and I both failed to set the 485 to 50 ohms. The edge is within the spec for the logic I was using to drive the output.

I built it for calibrating my 465 and Dumont 1060. As luck would have it, I picked up a Tek 106 for $10-15 which solved my problem.

I have a pair of 106s I need to test and sell. They may be old, but for a 100 MHz scope they do the job. Not that there's much you can adjust on a DSO.

Have Fun!
Reg


--------------------------------------------

On Fri, 3/15/19, Jim Ford <james.ford@...> wrote:

Subject: Re: [TekScopes] 11801 diagnostic help
To: TekScopes@groups.io
Date: Friday, March 15, 2019, 6:50 PM

I'm envious of your scores! 
Some day I will get back into owning and operating 11000
series gear....Jim Ford Sent from my Verizon, Samsung
Galaxy smartphone

Albert Otten
 

Hi Reg,

The first thing I look at is the total Ontime and power-ups count. I have seen11801x/CSA803xx with useful display but Ontime of over 140 khrs. That must be due to some out-of-range condition; the Ontime also doesn't get updated any more.
I'm curious to hear what your 11801 reports.
I also have a CSA803 with a very crisp display, Ontime just a few hundred hours and perfectly clean inside.
As to the battery Error, this error can show up intermittent. So it's not really sure that reseating some components solved your problem.

Albert

Reginald Beardsley
 

Albert,

The reseating resolved it not getting past the power on test. I've got NVRAM replacements on the way from the UK courtesy of another member of the group who got the last two that RS had in stock.

I've not yet been able to find an 11801 user manual or service manual. There are a couple of the latter on eBay, but I've still not verified they are for the 11801. There are no copies of either on the internet. I spent several hours running into incorrectly labeled copies of the 11801C manual. It's a good bit different from the 11801.

Because of the E5622 error I can't exit the extended diagnostics.

Someone else reported an on time of 30,000 hours. It may well be that they were being used to monitor data links with the screen brightness turned down and infinite persistence. i can easily see someone doing that at the head end of a subsea cable or satellite link.


Reg

--------------------------------------------

On Sat, 3/16/19, Albert Otten <aodiversen@...> wrote:

Subject: Re: [TekScopes] 11801 diagnostic help
To: TekScopes@groups.io
Date: Saturday, March 16, 2019, 5:14 AM

Hi Reg,

The first thing I look at is the total Ontime
and power-ups count. I have seen11801x/CSA803xx with useful
display but  Ontime of over 140 khrs. That must be due to
some out-of-range condition; the Ontime also doesn't get
updated any more.
I'm curious to hear
what your 11801 reports.
I also have a
CSA803 with a very crisp display, Ontime just a few hundred
hours and perfectly clean inside.
As to the
battery Error, this error can show up intermittent. So
it's not really sure that reseating some components
solved your problem.

Albert

Bob Koller
 

At KO4BB there is the factory diagnosis manual. Pretty cryptic, but has lots of information. Service manuals are available, but no schematics..

Reginald Beardsley
 

It's the 11801C manual despite what it says on the website. It's enough different I can't even Identify the boards using it.

My original problem is solved and I have NVRAM replacements en route from the UK. So in 8-10 days I'll be able to resume work. Hopefully with 11801 manuals in hand rather than manuals for later variants.

--------------------------------------------

On Sat, 3/16/19, Bob Koller via Groups.Io <testtech=yahoo.com@groups.io> wrote:

Subject: Re: [TekScopes] 11801 diagnostic help
To: TekScopes@groups.io
Date: Saturday, March 16, 2019, 9:46 AM

At KO4BB there is the factory
diagnosis manual. Pretty cryptic, but has lots of
information. Service manuals are available, but no
schematics..

Albert Otten
 

Hi Reg,

IIRC you can exit the Extended Diagnostics screen by pressing the Exit touch-screen field two times.
Another possibility to have the instrument at least doing something is to bypass the Self test and Extended Diagnostic tests by setting jumpers J712 and J713 on the I/O board to the 0 position. These jumpers are difficult to reach with the board in situ, I found it easier to remove the board and then change the jumper settings.
Albert

On Sat, Mar 16, 2019 at 02:31 PM, Reginald Beardsley wrote:


Because of the E5622 error I can't exit the extended diagnostics.

Reg

Reginald Beardsley
 

Albert,

Thanks. The exit and debug buttons are the only ones that are not active when it stops. Setting "stop on error" off has no effect.

With NVRAM replacements on the way and no service data yet, I think I'll wait until I get the chips and the correct manual. I'd like to have it working properly and passing all the diagnostics before I plug in the SD-22s. No sense getting in a hurry and causing extra problems.

The only boards with identifying labeling are two memory boards and a waveform compression board. IIRC from when I removed the boards and reseated them, two of the boards don't have any silkscreen labeling at all. The fabrication is very different from the ones made by Tektronix.

Once I have the chips and the manual I'll take it apart, identify the boards and label them. I also plan to copy all the ROMS while I have it apart. Despite their age they are still very impressive instruments. I also plan on scanning the manuals I get and sending them to the repositories.

Reg


--------------------------------------------

On Sat, 3/16/19, Albert Otten <aodiversen@...> wrote:

Subject: Re: [TekScopes] 11801 diagnostic help
To: TekScopes@groups.io
Date: Saturday, March 16, 2019, 3:14 PM

Hi Reg,

IIRC you can exit the Extended Diagnostics
screen by pressing the Exit touch-screen field two times.
Another possibility to have the instrument at
least doing something is to bypass the Self test and
Extended Diagnostic tests by setting jumpers J712 and J713
on the I/O board to the 0 position. These jumpers are
difficult to reach with the board in situ, I found it easier
to remove the board and then change the jumper settings.
Albert

On Sat,
Mar 16, 2019 at 02:31 PM, Reginald Beardsley wrote:

>
>
Because of the E5622 error I can't exit the extended
diagnostics.
>
>
Reg
>

 

On Sat, Mar 16, 2019 at 04:45 PM, Reginald Beardsley wrote:

Hopefully with 11801 manuals in hand rather than manuals for later variants.
Seem to be a hard one to find. I scanned mine and you can find it here for some time:
www.hakanh.com/dl/temp/11801_Service.pdf
It is OCR'ed and bookmarked. Feel free to upload it to TekWiki.
/Håkan

Reginald Beardsley
 

Thank you!! I just bought the user manual, so I'll be scanning it when it arrives. There is a paper copy of the service manual on eBay for $35 which I will buy if the seller will verify it is the correct manual, though now that I have a confirmed part number I may go ahead.

But now that I have the correct manual I can at least identify the boards and while I'm at it copy the ROMS.

I found so many 11801C manuals online listed as 11801 it was ridiculous.

Have Fun!
Reg

--------------------------------------------

On Mon, 3/18/19, zenith5106 <hahi@...> wrote:

Subject: Re: [TekScopes] 11801 diagnostic help
To: TekScopes@groups.io
Date: Monday, March 18, 2019, 4:54 PM

On Sat, Mar 16, 2019 at 04:45 PM,
Reginald Beardsley wrote:

> Hopefully with 11801 manuals  in hand
rather than manuals for later variants.

Seem to be a hard one to find. I scanned mine
and you can find it here for some time:
www.hakanh.com/dl/temp/11801_Service.pdf
It is OCR'ed and bookmarked. Feel free to
upload it to TekWiki.
/Håkan

Reginald Beardsley
 

Albert Otten wrote:

Another possibility to have the instrument atleast doing something is to bypass the Self test and
Extended Diagnostic tests by setting jumpers J712 and J713 on the I/O board to the 0 position. These jumpers are difficult to reach with the board in situ, I found it easier to remove the board and then change the jumper settings.

The only jumper labeled was J710, so I assumed the number went up went up from there. J712 and J713 were set to the right, so I moved them to the left, replaced the board and powered it up.

There was no change in behavior.

In reading the service manual for the 11801 it seemed to indicate that a sampling head needed to be installed. I tried it with one of my SD-22s installed, but that had no discernible effect.

Albert Otten
 

Hi Reg,

You moved the correct jumpers (Fig. 1-1 in the Diagnostics manual). I suppose (just suppose) now that the Exxxx error is too severe. When the battery in the Dallas battery is low, the NVRAM memory chip should still work but lose its content after power off. The corresponding error is T1331. Probably the chip inside the Dallas unit does not function properly anymore, i.e. does not guide the mainframe 5V to the memory chip when mainframe power is present.

The scope should power up normally even without any plugins. Of course many function simply are not available then, but you can see things like instrument options and identification.

Albert

On Sun, Mar 24, 2019 at 04:48 PM, Reginald Beardsley wrote:


Albert Otten wrote:

Another possibility to have the instrument atleast doing something is to
bypass the Self test and
Extended Diagnostic tests by setting jumpers J712 and J713 on the I/O board to
the 0 position. These jumpers are difficult to reach with the board in situ, I
found it easier to remove the board and then change the jumper settings.

The only jumper labeled was J710, so I assumed the number went up went up from
there. J712 and J713 were set to the right, so I moved them to the left,
replaced the board and powered it up.

There was no change in behavior.

In reading the service manual for the 11801 it seemed to indicate that a
sampling head needed to be installed. I tried it with one of my SD-22s
installed, but that had no discernible effect.

Albert Otten
 

Hi Reg,
One more remark. With Extended Diagnostics disabled you can (probably) still control the 11801 via GPIB. See for instance my CSA803 repair, message 148037.
Albert

Reginald Beardsley
 

Albert,

Where do I find a diagnostics manual for the 11801? Finding *any* manuals at all has been like looking for a unicorn. Days of searching turned up 11801A/B/C documents. But no 11801 documents.

I still get an E5622 error after my misadventure with U511.

In my view we really need to get this sorted out before a lot of very fine instruments become junk. Component level documentation for an 11801 would probably have sot $150-200K NRE at the time it was introduced.. Not providing that on a $25K (1989) instrument is obscene.

Thanks for your help.
Reg


--------------------------------------------

On Sun, 3/24/19, Albert Otten <aodiversen@...> wrote:

Subject: Re: [TekScopes] 11801 diagnostic help
To: TekScopes@groups.io
Date: Sunday, March 24, 2019, 1:47 PM

Hi Reg,

You moved the correct jumpers (Fig. 1-1 in the
Diagnostics manual). I suppose (just suppose) now that the
Exxxx error is too severe. When the battery in the Dallas
battery is low, the NVRAM memory chip should still work but
lose its content after power off. The corresponding error is
T1331. Probably the chip inside the Dallas unit does not
function properly anymore, i.e. does not guide the mainframe
5V to the memory chip when mainframe power is present.

The scope should power up
normally even without any plugins. Of course many function
simply are not available then, but you can see things like
instrument options and identification.

Albert


On Sun, Mar 24, 2019 at 04:48 PM, Reginald
Beardsley wrote:

>
> Albert Otten wrote:
>

> Another possibility to have the
instrument atleast doing something is to
> bypass the Self test and
> Extended Diagnostic tests by setting
jumpers J712 and J713 on the I/O board to
> the 0 position. These jumpers are
difficult to reach with the board in situ, I
> found it easier to remove the board and
then change the jumper settings.
>
> The only jumper labeled was J710, so I
assumed the number went up went up from
>
there.  J712 and J713 were set to the right, so I moved
them to the left,
> replaced the board
and powered it up.
>
> There was no change in behavior.
>
> In reading the
service manual for the 11801 it seemed to indicate that a
> sampling head needed to be installed.  I
tried it with one of my SD-22s
>
installed, but that had no discernible effect.
>

Albert Otten
 

Hi Reg,

I thought this manual had been mentioned before. I meant the last manual listed at
tekwiki, http://w140.com/tekwiki/wiki/11801 . Also here:
http://www.ko4bb.com/getsimple/index.php?id=download&file=Tektronix/Tektronix_11801_Factory_Diagnosis_Manual_Operator_Manual.zip

Albert

On Sun, Mar 24, 2019 at 08:13 PM, Reginald Beardsley wrote:


Albert,

Where do I find a diagnostics manual for the 11801?