Re: 11801 diagnostic help

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.


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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