Tektronix 465B Board Removal Video (A Deeper Look)
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- เผยแพร่เมื่อ 16 ก.ย. 2021
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This video was another viewer request on how to remove the boards from a 465B. There is not much trouble shooting in this video as it is mainly procedural in nature. There were however some issues in the power supply.
** Repair exposes the Tech to mains electric and should only be done by trained personal. Errors can be fatal. ** - วิทยาศาสตร์และเทคโนโลยี
The intricacy of a Tektronix scope makes a Swiss watch look like a children's erector set.
Absolutely support the notion of having a good analog scope on any development or diagnostics bench. Today a 'decent' DSO can be obtained at a modest price, but there are things that they just don't do, that an analog scope does. Highly recommend having both. In addition to my collection of 400MHz 7000 series and 2247A portable, I use a Siglent 200MHz. Mostly, the DSO gets used in FFT mode, driven by the output of AA501 distortion set. The analog 2247A has a digital co processor that has a full range of features. I purchased it new when it was released. Never had a regret. It IS the most used scope on my bench...which is focused on R&D of high end audio reproduction and recording equipment. Nice job on keeping these Tek goodies going.. They are awesome devices, well worth the effort to keep going.
Totally agree, anything up to 500 Mhz can and over about 100Hz can easly be done in analog Under that it can get hard to measure the scrolling dot. Over 500 Mhz trace brightness becomes and issue with out creative solutions. (Micro channel plate CRT's and "brighteye") But these have their own drawbacks.
Thank you. I also recently purchased a 465 and this video is very useful. Have to remove the attenuator, b channel because shaft either broke or disconnected. Um perhaps use a deep socket with a universal drive on 1/4” ratchet drive set. Also label with masking tape a, b, c, and etc and lots of pics. And hope something unobtainium won’t break 🥸.
10:10 You can also use another soldering iron together with the desoldergun to heat the pad faster that the gun can do on it's own.
Fascinating peace of testgear these Tek scopes. They really knew how to design stuff back then.
Yea that board was able to sink a lot of heat before things started moving. The gun I was using was no slouch in the thermal department either. This one could have been designed better for serviceability. like changing the indicator lights on the non B 465 the hole vertical section needs to come out. But still wonderful units. I still love the 7K frames as long as one can take the hit with the size penalty. The 7K frames are HUGE .
My 465M is so different and much easier to disassemble as they apparently designed it to be easy to swap whole assemblies in the field...first time I opened it up I was looking for a fan, what no fan? Oops, the M's don't have a fan but a huge heatsink on the rear panel. Nice work, wish I had your skill set with these! 73 - Dino KLØS
Thanks Dino Papas, I have not been in a 465M yet I don't have an example in the lab. I might have to work on that. I have also had some requests for 2xxx series scopes so I will have to see what I can come up with. My other half is starting to ask about storage so I might have to start moving some of the units on once they are repaired and working.
Thanks for showing the disassembly and reassembly process. Where did you supply the PSU filter capacitors from? Nowadays it is difficult to find with the same pin distance.
I had one scrap unit on hand that I was able to transplant the caps form. On the other repairs I have used capacitor adapter boards Well documented in the 576 rebuild videos. These are upgraded to brand new 105 degree C caps. There is an adapter plate that has been made for the 465B if I remember correctly. These tend to be just an interface PCB to make the mechanical connections. Tek had a bad habit of linking grounds through the cap cans. So all the connections need to be made.
@@ZenwizardStudios Can you put a link to the non-capacitive screwdrivers. I have a set but yours seem nicer :)
Aven 13231 6 Piece Ceramic Adjuster Set It was an amazon acquisition.
@@ZenwizardStudios Thank you
I really enjoy your videos very informative. Can you please tell me What replacement capacity you used to replace the 5000 µF? The reason I ask is because I need to replace the same capacitor and the nearest value I can find is 4700 µF would it be okay to use that as a replacement?.
It would be better to go slightly over on capacitance other than under. Capacitor tolerance ranges were very wide and get worse the further back in time you go. Voltage is another story. Vintage capacitors were very tolerant of over voltage and surge voltage. Modern caps are NOT AT ALL. You can not ask a modern cap to run at higher then normal voltage even for a short time they will over heat and burst. At a +20% tolerance a 5000uf cap can be up to 6000 uf and still be considered in spec so a 5100uf,5200uf would be fine as well. Given the counterfeit parts I recommend a reliable source the standard parts houses.
Thanks for this deep dive video. I need to clean/replace some of the square body pots on the main board and it appears that the board will need to be removed to do so. Do you have any plans to show the removal of a 465B main board?
Hi Tom,
Cleaning can be done mainly with out removal. replacement however will require removal. The pots are not sealed a cleaning agent like IPA can be wicked in to the control and then the control exercised. Removal of the main board of a 465 requires extensive tear down of the scope as there are regulators that need to be demount from heat sinks as well as some things from the HV supply including all the controls that are on coupler shafts. If there is a need I can see what we can do. I have not found anything yet other than control replacement that requires that level of disassembly. The cap replacements I have needed to do can be done from the top side of the board. And the controls have cleaned up nicely. I hope this is also the case for your unit. Allow sufficient dry time especially for the controls in the HV supply. Arc over in the control is a possibility.
Zen
@@ZenwizardStudios I did open one of the square pots by loosening the 4 flat screws and some prying to get a spray of contact cleaner inside. Alot of grease goofe ran out on the pcb....and dang, it went from smooth to crusty and heavy! What am I missing? Should there be some grease inside there?
@@tto009Send me an E-mail on this one.
I have a 465 with ch 1's 10x indicator burned out. Would be amazing if you have a chance how to get to these bulbs... Hopefully without too much disassembly.
unfortunately that one is a TASK to get those unburied. Changing the lamps is not an easy job.
I've got a 465 that works wonderfully except that there are issues with the Time/Div and Delay Time switch. I purchased the scope from a person who did not want to fix it after it had been badly damaged in shipping. I was able to repair everything except the Time/Div switch variable knob which was pushed in so hard that it totally broke the rotaryswitches had also been damaged. I was able to do some repairs but I've never been able to get that assembly to work properly. I've looked everywhere for instructions on how to align that assembly but can't find anything. The scope is totally usable unless I want to see a delayed sweep. (Luckily I have a 7854 on the bench that I use for that, if needed.) It would be great to see a detailed video on how to get that assembly aligned properly.
Hi John,
I know that feeling. I have a 7854 on the bench that was really banged up in shipping as well. Now it has a weird compression in the digital section. Analog is ok but the digital board has some issues. It worked for about 1.2 a second shrank and has stayed there. I am nearing completion of the test card I needed to calibrate a 7854 when I get boards in I will do a video on that as well then I might tackle a complete recall of my working 7854. I have a video out that goes in to a calibration of a 465B horizontal section th-cam.com/video/0g4dvpv3RBI/w-d-xo.html but it might be different for a 465 nonB. I currently do now have an example of a 465 non b in the lab so I will need a unit to work on some videos for that scope.
@@ZenwizardStudios I watched the video on the horizontal section calibration. Very nice! I never did a full calibration on the 465 (I probably should - in my spare time!) but everything I've thrown at it seems correct, so I'm guessing it's in pretty good shape. Same for the 7854. I got that for an absolute bargain. It came without any plugins but I've since purchased a bunch of calibrated plugins. The scope is working perfectly, both analog and digital. I got the frame for about $150 which I consider a real bargain since it is in great shape. I still wish I could fix that Time/Div switch assembly on the 465 though. The mechanics don't seem that difficult, yet I can't figure out how to get it to work properly. I even started looking for a replacement board but haven't had any luck yet. :-(
John, My 7854 is out of cal unfortunately. I think it has been "adjusted" by the previous handlers the digital sections and the analog do not line up correctly. Hence the need to recreate the test card. Other than that the scope works just fine. The 2nd 7854 is going to be my test scope for the analog card. It got really smashed in shipping. the back of the scope was crushed and there is damage to the digital board as well. So using it for test card development. If i get the test card working it will be able to to used as an analog scope at 400 Mhz so not a total loss but still disappointing. If you need I have a 465B parts scope that does not have the vertical section any more. It came to me with out the virtual pre-amp board. So i have a trigger board and timing board of unknown function that I can pass on if it will work. Shoot me an E-mail (in the about section of the channel page) if it will be of use.
@@ZenwizardStudios - Thanks for the offer but with the research that I've done, it appears as though the differences between the straight 465 and the 465B are too great. I had found some timing boards online for the 'B' model but it doesn't look like they can be used as a direct replacement, unfortunately. Perhaps one of these days a 465 timing board will pop up. In the meantime, I still use it as my go-to portable scope and it works great for that!
John, when you get a chance send me an e-mail. I have something I would like to send your way.
Why didn't you Show any Cleaning of Parts!?
How do you access those risky capacitors on the bottom board below the high voltage cover?
The main bulk DC filters or the high voltage caps? The HV cover in held on by a few screws most of the time, with care, the board can be serviced from the top side and does not need to be removed. If there is ceramic strip involved then solder choice becomes important as well.
@@ZenwizardStudios Not the big ones. The one you refer to as the "troublemaker" in 7:52. Along with two others. How do you change them without taking the whole bottom pcb off? I mean, the whole crt and alot of other stuff is above it.
@@tto009 AHH. Those can be serviced from the top side of the board. It and the CRT can stay in place lead length when putting the new caps in is critical because to much lead can short out the component to on the underside. But I service them from the top well bottom side of the board. the plated thru hole and the lead make sure the heat from the iron makes it to the under side of the board. I do have a Hakko FR-410 that makes cleaning up the empty hole easier.
@@ZenwizardStudios ok, thanks. I have a hakko 410 as well. Will have a look at it from the top side then.
Is a Tek 2230 Worth for reparier 🙈🙈
It would very much depend on a number of factors. For example the extent of the repairs needed weighed with the life left in the tube. I could see that going both way where in one direction repairs makes sense in the other it could be beyond economical repair.
Thx for respond
I will try to Check the crt First