EEVblog Electronics Community Forum

Products => Test Equipment => Topic started by: Galen on October 21, 2020, 12:53:35 pm

Title: Disassemble Tek P6139A
Post by: Galen on October 21, 2020, 12:53:35 pm
Got 2 P6139A. But I can't make proper compensation adjustment for one of them, always over compensation. So I decided to open it to check inside. Blow is the inside picture, and the schematic.
Title: Re: Disassemble Tek P6139A
Post by: Galen on October 21, 2020, 12:56:54 pm
backside of the PCB.
Title: Re: Disassemble Tek P6139A
Post by: Galen on October 21, 2020, 01:05:52 pm
I found the handheld tip between the 2 probes are different. Refer below picture.  The more thin tip at the right is the one that can't adjust proper compensation.
So I switched the tip, then the problem one can adjust proper compensation, and the good one, now with the thiner tip can't get good compensation.
So the tip looks like is the problem. The probe cable that has thiner tip maybe from other probe, not P6139A.
Title: Re: Disassemble Tek P6139A
Post by: Galen on October 21, 2020, 01:11:09 pm
So, if I can find the right tip, this probe can be fixed.
Title: Re: Disassemble Tek P6139A
Post by: alm on October 21, 2020, 03:07:22 pm
The tip hybrids are color coded, one color near the tip, and another one at the rear. This indicates for which model probe it is. There's a list of them here: https://www.tek.com/datasheet/passive-and-active-probe-general-replacement-parts (https://www.tek.com/datasheet/passive-and-active-probe-general-replacement-parts). From that you should be able to see for which probes the tip hybrids are. Likely the thinner one is from a 2.5mm probe like P6131. They are (or were) available from Tek as spare parts. Probably not cheap.
Title: Re: Disassemble Tek P6139A
Post by: Galen on October 22, 2020, 12:37:01 am
Very great information alm, thank you very much. now I know which tip hybrid I need to find - tip blue and tail yellow.
Title: Re: Disassemble Tek P6139A
Post by: fixitanonymous354 on October 22, 2020, 04:15:07 am
CalTronics makes a replacement for the P6139A model# CT3290RA, catalog http://www.caltestelectronics.com/documents/Cal_Test_Cat_No_23.pdf (http://www.caltestelectronics.com/documents/Cal_Test_Cat_No_23.pdf) page 14 shows some replacement tip, i dont know how well it will fit the original probe, but i bought a replacement ground wire and its a good fit.
Title: Re: Disassemble Tek P6139A
Post by: Galen on October 22, 2020, 09:36:37 am
Thanks a lot fixitanonymous354. can't download it.  But anyway, I found this tip hybrid in local SH vendor, 12 bucks.  Ordered.
Thanks again.
Title: Re: Disassemble Tek P6139A
Post by: korlatos on October 22, 2020, 09:10:44 pm
I bought a Cal Test CT3667 replacement tip for my P6139A and it works (and fits) great.
Title: Re: Disassemble Tek P6139A
Post by: Galen on October 25, 2020, 02:24:16 pm
Quote from: korlatos on October 22, 2020, 09:10:44 pm
I bought a Cal Test CT3667 replacement tip for my P6139A and it works (and fits) great.
Glad to know this.  still waiting for the tip hybrid.  will report when received.
Title: Re: Disassemble Tek P6139A
Post by: Galen on November 01, 2020, 04:47:51 pm
Just received the right tip hybrid, installed, and the compensation now is normal.  I have no device and procedure to adjust another capacitor (the blue one), so keep it as is.