Tektronix Technical Forums are maintained by community involvement. Feel free to post questions or respond to questions by other members. Should you require a time-sensitive answer, please contact your local Tektronix support center here.

MDO4034B + TPA-BNC + P6247?

Post Reply
andyturk
Posts: 12
Joined: August 16th, 2017, 7:50 am
Country: United States

MDO4034B + TPA-BNC + P6247?

Post by andyturk » September 13th, 2017, 4:09 pm

I've got a P6247 differential probe plugged into my MDO via a TPA-BNC. The TPA-BNC is recognized by the scope, but the diff probe itself is not. The probe model list for that channel pops up a big list of choices, but the P6247 isn't one of them. Should it be?

The diff probe seems to be working in that when I connect it to the probe compensation port, it reads an amplitude of ~250mV with attenuation set to 10.

The probe head is noticeably warm to the touch, about 40C according to my thermometer. Is that normal?

Last question... where the probe connects to the scope/adaptor, there are 7 pogo pins. On this particular probe, one of the middle pins in the group of 4 seems to have lost its spring. It's just pushed into the sleeve and probably isn't making contact when connected to the scope. Could this explain why the probe isn't showing up in the menu?

David N
Tektronix Applications
Tektronix Applications
Posts: 558
Joined: July 31st, 2008, 8:26 am

Re: MDO4034B + TPA-BNC + P6247?

Post by David N » September 14th, 2017, 10:08 am

The P6247 should be recognized by the MDO4034B through the TPA-BNC adapter. I suspect that the defective pogo pin is causing the probe to operate correctly thus not being recognized by the scope. Could also be causing the probe to operate warmer than normal. It does get quite warm during operation.

You can replace the damaged pin by ordering 131362702 for a single pin or 050331400 for a set of 7 pins. Instructions are in the P6246 & P6247 Service Manual (search tek.com for 070989903.)

andyturk
Posts: 12
Joined: August 16th, 2017, 7:50 am
Country: United States

Re: MDO4034B + TPA-BNC + P6247?

Post by andyturk » September 14th, 2017, 10:31 am

Thanks for the quick reply!

So when everything is working through the TPA-BNC, I should see P6247 in the probe list?

Do you know if there's a way to push the bad pin out from the back? (which would obviously entail some disassembly) The tip of the bad pin is basically flush with the sleeve and impossible to grab with pliers or tweezers.

https://photos.app.goo.gl/jWwdYnQuRjeSFajG3
Last edited by andyturk on September 14th, 2017, 11:43 am, edited 1 time in total.

David N
Tektronix Applications
Tektronix Applications
Posts: 558
Joined: July 31st, 2008, 8:26 am

Re: MDO4034B + TPA-BNC + P6247?

Post by David N » September 14th, 2017, 11:11 am

Yes you should see the P6247 in the list. It should first list the TPA-BNC when it is connected, then when you connect the P6247 to the TPA-BNC it should then change and indicate the P6247 is connected.

You may want to check the instruments f/w version to make sure the MDO4034B is running the latest f/w. The lasted for this model is v3.20.

As for the broken pin, I could not retrieve the image you attached.

You might trying to remove the plastic BNC collar which may give you a bit more access to pull the pin from the front of the connector.
Attachments
TekProbe Collar Removal.PNG
TekProbe Collar Removal.PNG (49.53 KiB) Viewed 30870 times

andyturk
Posts: 12
Joined: August 16th, 2017, 7:50 am
Country: United States

Re: MDO4034B + TPA-BNC + P6247?

Post by andyturk » September 14th, 2017, 11:45 am

I've got v3.22 on the scope, which should be good. Sorry about the photo link. I edited the post to use a different link that you should be able to see.

Thanks for your help with this.

David N
Tektronix Applications
Tektronix Applications
Posts: 558
Joined: July 31st, 2008, 8:26 am

Re: MDO4034B + TPA-BNC + P6247?

Post by David N » September 14th, 2017, 12:09 pm

I can see the photo now. Looks like the pin is just stuck. Once the BNC collar is removed you might be able to use a small, sharp knife edge to grab part of the pin and coach it out far enough to pull it out. If not it would need to be sent in for repair.

andyturk
Posts: 12
Joined: August 16th, 2017, 7:50 am
Country: United States

Re: MDO4034B + TPA-BNC + P6247?

Post by andyturk » September 15th, 2017, 10:06 am

David,

I've been searching for a source for replacement pins, but the Tek website returns nothing for those two part numbers. Same for mouser and digikey. Where can you get these things?

David N
Tektronix Applications
Tektronix Applications
Posts: 558
Joined: July 31st, 2008, 8:26 am

Re: MDO4034B + TPA-BNC + P6247?

Post by David N » September 15th, 2017, 10:15 am

Those would have to be order directly from Tektronix. You can call 1-800-833-9200, prompt 1 for sales.

andyturk
Posts: 12
Joined: August 16th, 2017, 7:50 am
Country: United States

Re: MDO4034B + TPA-BNC + P6247?

Post by andyturk » September 15th, 2017, 1:02 pm

Good news, with your x-acto trick, I was able to tease the shy pin out of its hole. Along with it came a small piece of white fluff.

I'm 100% sure that pin is now contacting the TPA-BNC, since there's a new mark on the adaptor contact. It was previously unused and after I'd hooked everything up before the other 6 pins from the P6247 made marks on the gold adaptor contacts. After getting the last pin out, I now have 7 marks on the adaptor.

However, the scope still doesn't recognize the P6247. The best I can do is choose some other probe type (e.g., CT-6) that sets the 50 ohm termination. What other factors are affected by the probe recognition system? Are there any drawbacks to using a P6247 that isn't recognized by the MDO?

David N
Tektronix Applications
Tektronix Applications
Posts: 558
Joined: July 31st, 2008, 8:26 am

Re: MDO4034B + TPA-BNC + P6247?

Post by David N » September 15th, 2017, 3:33 pm

Glad you were successful in pulling the pin out. Not sure why it does not recognize the P6247. I would check to make sure that all the pins compress and release easily.

As for operating the P6247, if the scope is not recognizing the probe, you may not have full control of the probes functions as well as offset control.

andyturk
Posts: 12
Joined: August 16th, 2017, 7:50 am
Country: United States

Re: MDO4034B + TPA-BNC + P6247?

Post by andyturk » September 18th, 2017, 8:13 am

Interestingly enough, the P6247 now talks to the scope. I'm not sure what changed, but I turned on the scope in the morning and boom, it sees the probe. The offset adjustment works and the scope senses the attenuation setting.

There's a bunch of screen updating/flashing when I flip the div-by-10 switch, but it eventually calms down and shows the correct setting.

Problem solved.

Post Reply

Return to “Differential”

Who is online

Users browsing this forum: No registered users and 1 guest