What Problem Is Hiding In This Tektronix 2465B Oscilloscope?
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- Опубліковано 10 лют 2025
- Follow along as Erik replaces the components that are well on their way to failure in this Tektronix 2465B oscilloscope manufactured in 1989.
To learn more about safety capacitors watch my previous video:
• Failing RIFA Safety Ca...
#oscilloscope #tektronix #capacitor
Hy Erik, thank you ! certainly pointed to the sore points on mine too !
After desoldering 15 ohm resistor, one of them on my 2465b was open ….exactly like yours !
My 2465B was no longer working…now in the process of ordering the replacement parts.
I had also two failed caps on the other board the 180uf /40v blue caps…
Will post back when I am finished to point if anything else was bad :)
Best,
Eric
🙂
Thanks for watching Eric. Hope your 2465B turns out well!
ua-cam.com/users/postUgkx0pLCG62TomoFIhA3xJuTmyaotVcyf5m0?si=ReERBNNzMT6CdxE6
😊👍 I couldn’t find the way to incorporate the video of the boot so here is the photo at least 🙃!
Here the list of parts with current references (from Mouser)…
But there is a caveat the 15 ohms resistors are 1 watt resistors, (not 1/2 as in my order list ! , maybe I didn’t pay correctly attention or heard wrong on your video 😅, in the end I used a 2 watt resistor I had here, the one blown was (RT 1010 the outer one), the other one was good so I put it back, funny I think it’s the same one as yours that was blown…
Note: Those electrolytic caps are much smaller, physically, than the original ones, but higher voltage !
2465B
N° Mouser N° de fab. Fabricant N° client Description RoHS Cycle de vie Qté. Prix (EUR) Ext. : (EUR)
756-MFR4-15RFI MFR4-15RFI TT Electronics Résistances à couche métallique - Trou traversant 15 ohm 1% 0.5W RoHS : conforme 2 0,428 € 0,86 €
667-EEU-FR1H181LB EEU-FR1H181LB Panasonic Condensateurs électrolytiques en aluminium - Fils radiaux 50VDC 180uF 8x20mm LS 5.0mm RoHS : conforme 2 0,67 € 1,34 €
80-PME271M568MR30 PME271M568MR30 KEMET Condensateurs de sécurité 275V 0.068uF 20% LS=15.2mm RoHS : conforme 2 1,73 € 3,46 €
80-PHE850EB5100MB04 PHE850EB5100MB04R17 KEMET Condensateurs de sécurité 300V 0.010uF 20% LS=15mm RoHS : conforme NRND 1 0,632 € 0,63 €
80-PHE850EA4220KA1 PHE850EA4220KA01R17 KEMET Condensateurs de sécurité 300V 2200pF 10% LS=10mm RoHS : conforme NRND 2 0,558 € 1,12 €
And finally this is the video I couldn't figure out how to upload from my tablet :) , ua-cam.com/video/IO5VumA7wXU/v-deo.html
Hi Erik, You have explained everything in great detail in your video and you would be the best Electronic Tech on this planet. Thank you very much for all your time.
Thank you for the nice compliment and for watching!
Thanks for a great class today. I learned a lot. Also wondering if there is a better replacement for the rifa caps. But asd you say, The new ones are much improved.
Glad to know you found the video informative. Yes there are numerous manufacture choices for the safety capacitors. For example here is a link for a starting point at Mouser Electronics for thousands of types of safety capacitors by many manufactures.. www.mouser.com/c/passive-components/capacitors/?product%20type=Safety%20Capacitors&termination%20style=Axial%7C~Radial
Time to open up my bench test gear before trouble happens. Thanks!
Ha! I knew that was a 3585A from the bottom. I have worked on 4 of them in recent years.
I have a Tek 2445a with a dead battery. I am planning to change the battery, but I also want to recap the PSU just in case :).
Do you know if there are any compiled lists with Mouser/Digikey part numbers for the capacitors that need to be changed on the PSU (or anywhere else for that matter)?
I am not aware of a parts list for Mouser or other companies. I have done several Tek scope power supply recaps and I just went through and examined each capacitor and then purchased from Mouser using their website search tool to drill down to the correct parts needed. On future repairs I will include the part number list as other viewers have also asked this.
Hi
Good video
Did you have a supplier and parts list ?
Parts supplier was Mouser Electronics. I also use Digi-Key. I don't have a parts list, part numbers/identification was just based on the markings of the old parts.
@@EriksElectronicsWorkbench thank you for let me know
I have 2 units to repair
If there is not too much problem will like to have the part numbers for the special caps
Thank you
@@AlfredoGarcia-ov8sw looking over an order I placed at the time of the video and repair, the 0.068uf safety cap is PME271M568MR30, the 2200pf safety cap is R413F12204000M or possibly R413F122050T0K, I had purchased both types and don't recall which was used in this project. There may have been a 0.1 uf cap but any others I already had on hand, sorry I don't have the part numbers. If you look at the original parts they are marked with the voltage and capacitance and X and Y ratings. Also measure the lead spacing. Mouser and Digi-Key have great website search tools to locate the correct parts, just enter the known details and work through the results. Also RIFA is now made by KEMET if you are looking up by manufacture name.
@@EriksElectronicsWorkbench thank you
Have a nice week end
I have a 2465 that has a bad ground somewhere, a gremlin. I can't locate it because the tap that makes it go away moves every time. Sometimes a tap on the other end of the table is the only thing that makes it go away. It's very accurate, no trouble otherwise, sometimes the gremlin stays sleeping.
Intermittent problems like that are the worst to track down. Depending on what actually happens when the fault occurs might point to the area of circuitry and you could reflow all the solders in that area of the board.
@@EriksElectronicsWorkbenchIt puts bright, flashy noise on the CRT. I have a guess that it's a loose screw holding metal to metal. A zinc-x diode is possible. Of the 100 or so screws, which one? I think I'll tap it until it really fails. It works.
@@chaosopher23 yes that quickly gets complex to track down the issue. Possibly monitor the drive signals to the CRT and see if that narrows down the circuit. But if a tap corrects it then that is the simple fix :)
This is really good info. The safety cap thing is new to me, but I alwasy worked in embedded and FPGA, not in PSU design. I have a bunch of stuff from the 80s and 90s that I want to keep in good running order. I think it might be youtuber Curious Marc who's always talking about how the IEC plug input modules (the EMI filters with the IEC power cord pins) on old boxes tend to blow up and stink up the lab, is that the same issue, do you think? Are you also doing the electrolytics, seems like that's pretty much the #1 recommendation per the interwebz. Also, any experience with vintage EPROMs losing their code? My stable includes a couple old Tek digital scopes, some HP scopes, an old Data IO 212 programmer, and an HP logic analyser. Have my eye on some similar era Tek models as yours in the local surplus shop as well. Anyways, subbed, and will explore the rest of your vids.
Yes, older IEC plugs also can include RIFA caps, inside the can, and they can/do blow, too.
Thanks for watching and subscribing, and I'm glad you found the video helpful. Yes the EMI line filter could fail due to bad capacitors internally but often the EMI filters are hermetically sealed and the internal components are more stable than those exposed like the RIFA caps. Yes I often replace the electrolytic caps either as preventative maintenance or necessity from failure. I've not had EPROMs go bad in the older equipment but it is possible they can become corrupted. You can use a reader and copy the data to a new EPROM. The older Tek scopes are some of my favorites. I hope you are able to get the Tek scopes you found locally :)
@@EriksElectronicsWorkbench Thanks for the info. Seems like there's a lot of work to keeping the vintage stuff running, I've also been made aware of people who replace the 1990's era hard disks (like in my HP logic analyser) with SSDs via some adapters and disk cloning software to avoid the inevitable head crashes. Lots of projects to take on on the next little while!
8:30 the problem with using new Rifa caps is that you just don't know. The old ones took 30 years to blow up, and you're only 15 years into the new ones.
It will be interesting to see how they hold up. KEMET took over the manufacturing RIFA's. I've not had issues with their line of capacitors and other components.
Is there a way to calibrate the oscilloscope without a Time Mark Generator?
A time mark generator would be for the sweep time but not for the vertical gain so is only one possible item used in calibration. The signal produced by a time mark generator is not easily reproduced otherwise. You can check the sweep time in general by applying a known frequency accurate signal and check the graticules for proper period time indication of the waveform.
@@EriksElectronicsWorkbench Thank you
For high frequency calibration, I use a RF generator, like a Fluke 6060B, HP 8656B, etc...
For low frequency calibration and amplitude calibration, I use a HP 33120A, this HP must be charged to 50ohm for to assure amplitude value showed in display.
I have never heard of a capacitor referred to as a 'Safety' capacitor. What does that mean? Also, what is a Y or X rated capacitor? I've been working in electronics for 30+ years and have never come across that terminology before.
A safety capacitor is a capacitor is designed to fail in a safe way to prevent a dangerous condition to the user. I made this video which covers all the details.. ua-cam.com/video/GDTuHDsHHFA/v-deo.html Y and X are the classes (ratings) of the safety capacitors. Electronics distributors like Mouser and DigiKey have entire categories of safety capacitors.
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