TDS3012 System Error Message - Display Problem(Solved), broken encoders

[Ordinaryman1971]

Hi, just got a scope with this message on it. When extinguished, the message comes back every few minutes. When I ran diagnostics on the scope they all pass. The error log shows display error and it says:
499: 21 0 34 Graphics 125.88.4853/165/4505
Did anybody stumble upon problem like this, is it a known issue?
Not sure where to start the troubleshooting as the diagnostics pass every time I ran them.
Also, scope has few broken knobs, not sure if anybody has an assembly or spare encoders.
Also, looking for some blank option boards... or a programmed one to enable all the options
The scope seems to be a great score just because it came with the GPIB/Serial communication module, runs firmware 4.31, nice condition overall and... hackable which is the main reason I've got it

[james_s]

No idea about that error.

I bought knobs for mine from an ebay seller in Oregon, the encoders were fine but were a bit flakey until I got some contact cleaner in there.

The option modules are easy, the latest firmware enables adv trig and fft so if yours has one of those you can reprogram it yourself. I opened one of mine up and it's just a bog standard I2C EEPROM, I used my TL866 with a SO8 clip to flash it with the ENG code that unlocks all options. Most of the options are useless though so I've been thinking of flashing the two modules I have with the advanced video triggering and whatever else looks remotely useful. The others are things like SDI video that require an additional hardware module, and a bunch of obsolete communication standards.

[Ordinaryman1971]

I will have a closer look, measure voltages, just wonder why would it pass all the dgn and after this report the display error. By the way, display is fine, no problems at all.
I went through the manual but I found nothing relating to the error codes, it just says to return it to Tek for service.
Yes, one of the slots has an option card in it... let me get a look at programming this one...

[james_s]

Given my past experience with the self test routines on various things I'm not too surprised that there's a fault that isn't being caught by the test. First thing I'd do is check all the voltages, then look closely for bad soldering on any of the ICs in the digital section.

There's a screw under the sticker on those little option modules, I broke mine and had to glue it back together before I realized that. Don't update to the latest firmware before you send the commands to upgrade it to a TDS3052, only versions prior to 3.41 support that. After upgrading you can update to 3.41 and it will keep working.

[Ordinaryman1971]

Finally I've found some time yesterday to do the hack. I've downgraded the firmware to 3.39. The display error still persisted.
I've inputted the password and the upgrade command.... restarted... and an error is gone. Upgraded the firmware and no display errors anymore.
So, I guess it was some glitch with the firmware.... who knows.
So, I have 500MHz scope right now with 3.41 firmware...
Now I have to find the encoders to replace the broken ones and find a way to purge the error log... I have 500 display errors listed there.
I've tried to power up the scope with the button pressed on the back of the scope but I don't think it had changed anything....

[james_s]

I think there is a command you can send via the console to clear the error log, at least there is on the TDS700 series.

AFAIK the encoders are custom parts and not available. Are yours actually broken or just dirty?

[Ordinaryman1971]

The shafts on the encoders are broken off clean. I wonder if they are the same as the ones used in TDS200 series, I think I have a broken one somewhere here that had one of the encoders damaged but the rest of them was good.

[james_s]

I'm not sure, it wouldn't be too hard to check though. You might also be able to find some similar enough encoders with the same shafts, IIRC the Tek ones are made by Bourns.

Or you might find some cheap encoders or pots with the same type of end on the shaft and cut them off clean then solvent weld them or drill a little hole in the end and screw them together. Depends on how patient you are with fiddly work.