Re: 11801 diagnostic help

Reginald Beardsley


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.


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

Subject: Re: [TekScopes] 11801 diagnostic help
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.


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.

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