Tektronix MDO4104-6 Front Panel Microcontroller Failure

[joebot5]

Hello,

My front panel PCB on my MDO4104-6 scope was not responding to push button presses nor knob turns. My oscilloscope automatically was powering up when AC power was applied. The oscilloscope does boot up and channel 1 does appear. However, I can't adjust settings due to the front panel not working. Some of the front panel LEDs were on at random boot times. I can connect to the oscilloscope through OpenChoice with no issues. I've tried updating the firmware to the 3.18 version (last version to be made) but the front panel was still not functioning. I then ordered a replacement microcontroller for the front panel PCB and soldered on a new part. Now the oscilloscope won't power on (as expected since it controls the remote signal to the power supply). I forced the power supply to turn on when AC is applied by shorting the remote jumper header on the power supply. The oscilloscope boots up but no LEDs are on and no buttons work on the front panel. This is to be expected since the microcontroller is blank with no program to run. I would like to know if there is a way to reprogram the microcontroller on the front panel PCB. I don't see any information on firmware other than the 3.18 version that I don't think updates the software on the front panel PCB, but I could be wrong. Also, when I try the USB stick with 3.18 firmware, my oscilloscope won't try to update because it detects that the oscilloscope already has this firmware. I did place a TXT file named "forceinstall.txt" and this does force an install of the firmware, but the front panel still is dead. I did check with an ohm meter my soldering of the microcontroller to the PCB and from pad to pad to confirm no solder bridges. I ended up trying the LOCK command using the OpenChoice software tool to see if the main processor is preventing a firmware update to the microcontroller. I ran the command and forced the install with no luck.

Does anyone know of how to program the front panel PCB directly? I'm assuming that the firmware for the front panel is not public knowledge. When I reached out to Tektronix directly they stated that it would cost me +$5K and it may not work after they try fixing it.

Thanks

[Jwalling]

Will Tek sell the board?

[mikehank]

Hello joebot5,

The front panel microcontroller U302(I think) is a programmed part.  Without the flashed program it will do nothing.  When the scope FW is updated it checks for the latest code in the front panel controller and will update if needed.  If the boot sequence does not see the program in U302 the scope will not boot.

 As to a fix, find another MDO4k pull the chip and save a copy of it with prom burner.  Then burn that program into your new chip. 

Sorry it isn't easier....

[joebot5]

Hi Jwalling - Tek replied with saying they can try repairing the scope but the cost would be ~$5k and it may not work. They didn't offer selling me the front panel PCB. Thanks for the suggestion!

[joebot5]

Hi mikehank - thanks for your response. That is a good idea - i just need to get a working MDO4K at least a working front panel. If anyone knows of one available out on the web that would be appreciated.

[mikehank]

There is a company here in Oregon that has these parts and can program them.  The name is Norway Labs you maybe able to have them sell you a programed microcontroller.

[joebot5]

Thanks mikehank! I'll reach out to them and see what they say!

[voltsandjolts]

Installing new scope firmware might install firmware on the front panel mcu.
However, it would likely require that mcu to be functional and able to run some kind of bootloader code on command.

Those mcu's are gonna be copy protected, so copying firmware from a functional mcu to your blank mcu is a no go.
Tek won't give you a hex file to program a blank micro.
If the scope firmware includes the front panel mcu firmware, someone very smart might be able to extract it.

IMHO you are screwed, and you need a replacement front panel.

[voltsandjolts]

What type of mcu is it?

[mikehank]

Hello,

The front panel controller is not copy protected.  I have burned images into this processor and fixed front panels many times.  Without the front panel working correctly the boot sequence will hang.  The micro controller is on the I2C bus and when not happy the bus hangs.

[joebot5]

interestingly enough, my scope does boot up all the way after about 1min 30sec. i do have the power supply forced on through the remote on jumper on the power supply. i can get to the screen where it says the scope hasn't been compensated. this screen showed up after i used the "forceinstall.txt" method to force an install of an earlier version of the firmware, thinking that maybe an earlier version could install to the micro but that didn't work. thanks everyone for your thoughts and options!

[joebot5]

i just got off the phone with Norway Labs and the price they quoted is almost the cost that tektronix quoted for their repair efforts, a bit under nevertheless. i might just try going back to the drawing board on this one unless i can justify the expense. thanks everyone!

[feedback.loop]

Hello,

The front panel controller is not copy protected.  I have burned images into this processor and fixed front panels many times.  Without the front panel working correctly the boot sequence will hang.  The micro controller is on the I2C bus and when not happy the bus hangs.

Could you share the image please?

[joebot5]

hi mikehank - does the image have to specifically be from an mdo4104-6 or can a similar model work? just trying to keep options open if possible since mdo4104-6 models that are used are still fairly expensive, at least to me 

[mikehank]

Hello joebot5,

Any MDO4K will work.  A MSO/DPO will not work due to the keypad functionality.  Also MDO4KB, or MSO4KC will not work.   I would send you the program image but I don't have one.

[joebot5]

Thanks mikehank! That would make sense. I'll definitely keep my eyes open for an MDO4K scope, or at least someone who might have one. If someone on this forum would be willing to extracting the image from the front panel micro please let me know.

hi mikehank - do you know of a website perhaps that gives the process of extracting the image off of these chips? The microcontroller is a nxp MC9S08AW60. I'm assuming it would be connecting to the front panel pcb jtag header with a programmer such as the recommended one from nxp: https://www.nxp.com/products/power-management/motor-and-solenoid-drivers/powertrain-and-engine-control/universal-multilink-development-interface:UMultilink
Then in a tool such as MCUXpresso i could then read the memory on the chip and copy that as a hex file for later installation?

Thanks!

[EEVblog]

i just got off the phone with Norway Labs and the price they quoted is almost the cost that tektronix quoted for their repair efforts, a bit under nevertheless. i might just try going back to the drawing board on this one unless i can justify the expense. thanks everyone!

$5k to repair this is nuts.
Surely there is someone out there with an MDO4000 who wants to make a quick buck by copying the chip?

[Jwalling]

Hi Jwalling - Tek replied with saying they can try repairing the scope but the cost would be ~$5k and it may not work. They didn't offer selling me the front panel PCB. Thanks for the suggestion!

They won't "offer" selling you one.
Have you tried going here: https://www.tek.com/en/buy/request-parts-information and submitting a request?
Part # is 878-0388-01

[joebot5]

Thanks Jwalling! I have not tried that avenue but I just put in a request. I'll let everyone know how it goes.

[joebot5]

Hi everyone - I emailed my local rep for Tektronix and here is what he said:
"I checked with the factory and found that the front panel board for the original MDO4000 scopes is no longer available. Those scopes were discontinued almost 10 years ago."

If anyone does have an MDO4104-6 or an MDO4000 series scope (no B or C at the end) it would be great to work with you on getting the image off of the front panel PCB. Feel free to reach out to me on this forum.