Repairing Tektronix DPO4000/MSO4000 series scopes?

[pinkman]

I see these pop up now and again, in need of repair, for very good prices.  I've been looking for an MSO4104 for some time now and when these are listed in need of repair, the needed repair usually relates to the acquisition board.

The repair manual obviously states that the acquisition board must be replaced.  However, the few failures I've encountered seem that they are not related to some sort of EOS (per the owner's description of the slow and random onset of the problem), and more likely are some sort of component failure.  Two people have told me that the scope only fails when hot, so it works for a little while after startup and then must cool down again.  I'm thinking de-laminating BGA, failed discrete/passive, etc...  Has anyone had success/experience in doing any sort of module (PCB) repair on these newer Tek scopes?  I searched the 'net but found little to nothing on this.

[Omikron]

I see these pop up now and again, in need of repair, for very good prices.  I've been looking for an MSO4104 for some time now and when these are listed in need of repair, the needed repair usually relates to the acquisition board.

The repair manual obviously states that the acquisition board must be replaced.  However, the few failures I've encountered seem that they are not related to some sort of EOS (per the owner's description of the slow and random onset of the problem), and more likely are some sort of component failure.  Two people have told me that the scope only fails when hot, so it works for a little while after startup and then must cool down again.  I'm thinking de-laminating BGA, failed discrete/passive, etc...  Has anyone had success/experience in doing any sort of module (PCB) repair on these newer Tek scopes?  I searched the 'net but found little to nothing on this.

Hey pinkman! Did you ever get anywhere with this topic? I don't have any issues with my MSO at the moment, but it would be interesting to see how this pans out in the future.

[susan-parker]

Repairing the acquisition board is not going to be easy particually if it's one or more input channels that arn't working, most stuff is custom logic, unless it's something simple like the 50ohm input termination.

I have a DPO4104 on my bench, the AUX input has been blown up (the good news is that the four analogue channels still work).

Replaced U120 MAX6901 dual comparitor and U110 OPA656 OpAmp (B5C) but no joy.

Tek service info seems limited to board level replacement.

Anyone have any other ideas, please do tell

[darkstar49]

Hi,

I've got a dead DPO4034 in the drawer since quite a while...   problem is the PSU part on the upper right part of your pic (mainboard)... if you ever get a chance to take a high-res pic of that portion, I'd be highly interested... on mine, the labels of some components are barely readable...


Kind regards,
P

[susan-parker]

Hi,

Sorry, I no longer have the 'scope.

This is an unsized pic of the area from my original image file, best I can do.

Best,
Susan.

[xxx]

Has anyone had any luck repairing a tektronix mso4000 that doesn't boot?

[darkstar49]

"doesn't boot" is probably a bit short as a description of the problem...

sounds ? lights ? beeps ? ...

[darkstar49]

Thanks a lot... better than nothing...  ;-)

I don't have much time right now... but I'll give it a try soon... I'll replace all the caps and transistor ICs I can read the labels of (and those I can find a suitable replacement for, obviously...)
I don't put too much hope in this but those components are not expensive, so besides some (precious...) time, the financial losses will remain limited...

Cheers

[pinkman]

I would recommend checking the ESR of the caps and looking for shorts.  You should be able to at least tell if one particular bank (i.e. voltage rail) is shorted and then start pulling individual caps.  You should also be able to check most/all of those FETs without removing them - Those flat pack FETs can be a pain to replace.  What is the problem with yours?  One of the outputs not regulating?

[Samogon]

If someone can dupm firmware from eeproms of any Tek 4000 series units?

[andyturk]

If someone can dupm firmware from eeproms of any Tek 4000 series units?

http://www.tek.com/oscilloscope/mso4014b-software-0

[TiN]

I searched the 'net but found little to nothing on this.

There! You chance to become famous get the scope, fix it, and fill the void.
Chances of getting working scope are slim, but still possible, if you have enough patience, money and time. 

[TiN]

I just I'll just reply to myself, as I got dead DPO7K scope, which got to work, but ADC on channel 3 blow up after half-hour...
Anyone have source for dead scopes for donor parts? 

[tetech]

I decompress the software to a 4 gig USB stick and inserted said stick in the USB slot in the front of the scope turned it on waited half an hour turn it down off remove the USB stick turned it on and it worked. thank you!  Text says if that doesn't work then use the rear USB connections.

[rtekal]

Repairing the acquisition board is not going to be easy particually if it's one or more input channels that arn't working, most stuff is custom logic, unless it's something simple like the 50ohm input termination.

Hi,
I have a DPO4104 that fails SPC. On analysis I found that Channel 1 in 50 ohms mode has an offset voltage of +8mV approx  which is causing the SPC failure. The other channels are fine.

Has anyone faced this problem and repaired it? Any solutions are welcome.

Regards

[pinkman]

This thread still getting posts! Wow.

Don't have any info on what causes it on this scope but I think a good starting point would be to read up on what causes SPC failure on other tek scopes, the more recent, the better, and look for similarities in the analog front end for your scope vs. what you can find on older scopes.

I have a couple of these scopes now, needing small work, none have some catastrophic failure (like no boot/blank screen/etc) even after being switched off for years; these don't seem to suffer memory retention issues like the low quality Agilent -X series scopes.  I will want to resurrect my scopes someday, I really don't think a scope of this quality has been made since these.  I have had Agilent/Keysight MSO-X 500MHz scope on my bench for some time and I am getting tired of this cost-reduced garbage.

I welcome anyone with further information about these scopes to post here, architectural information, knowledge of firmware, or any information regarding fixes to common problems.

[mikehank]

With a setting of 90mv and below with 50ohms this is a direct shot into that channels preamp.  If you are seeing anything higher than 1-2mv output on the input the preamp has been damaged.  The preamp sadly is a BGA ASIC so its not an easy fix.