Tektronix 2465B repair attempt - Page 1
Forum section: electronics / repair

author: ThatElectronicsGuy
author_rank: Newbie
timestamp: September 24, 2025, 09:03:44 am
content: Hi,So recently I have bought myself oscilloscope that is tektronix 2465B with a wish that it will work right away. When it came which took a while, whooosh - I live in Poland, I was excited. I plug it in to test if it works and it did for like 30 seconds. Then all I remember were smoke, sizzle and tears hahah. No but seriously it died on my eyes. So I opened and of course RIFA capacitor broke. No worries, easy right. I replaced it and tried to turn it on but all I've seen was momental blink of ray and all the lights were continously on. I have seen that our friend on youtube had similar issue, so I have replaced all the caps on power board. So I tried again and then smoke and fire happened. It turned out that one cap needed to be with specific characteristic for high ripple. No worries I just bought other nichicon series cap which would be CS series (all the others were CY) and tried to turn it on. Success! Now I made it without smoke hahah, neverthless it still doesn't work.. I have a video of my current situation. I have a progress because now it looks like it moves from the initial freeze and i have ray dot trace on the screen, and this one LED under trigger section shining (I believe it shines before scope starts to auto calibrate in healthy models). But now my only clue is to check pads on logic section, but I am already performing two projects simultaneously and I don't have too much time to dig into the cirucit and search for the issue, that's why I ask you guys here. Maybe you have similar experiences, any ideas?*link to google drive with video where I show what's happening in notepad**Have wonderful day guys

author: Kwakerman
author_rank: Regular Contributor
timestamp: September 24, 2025, 09:37:21 am
content: Link doesn't work for me.Have you checked all the supply voltages (I think it is J119 on the main PCB from memory), the service manual list them and their tolerances.If you have one LED lit then that is probably indicating a self test failure, pressing the A/B Trig button may let it go past this fault and start up. You may then get a 'Fails test' report with a code on the bottom of the CRT.Likely issues are leaking capacitors and corrosion damage on the A5 PCB (if it is the later SMD design) and also a flat memory battery and lost calibration settings. Early A5 PCBs have a battery on the bottom right side, later ones have a DALLAS chip in the middle of the PCB.

author: Kwakerman
author_rank: Regular Contributor
timestamp: September 24, 2025, 09:41:32 am
content: Also if you are running it with the case removed make sure you have a fan blowing on the main PCB to cool the large Hybrid chips.

author: ThatElectronicsGuy
author_rank: Newbie
timestamp: September 24, 2025, 10:57:51 am
content: Did you try to open file and copy link from there? Just checked and for me it works.So I haven't checked supply voltages but I surely will do. I tried A/B trig button and it didn't do anything.I attached picture of how it looks like anyway.

author: Kwakerman
author_rank: Regular Contributor
timestamp: September 24, 2025, 12:27:21 pm
content: Check the power supplies first (voltage and ripple), its listed in Section 5 of the service manual (Adjustment / Calibration). If they are Ok then I think you have an A5 issue, the service manual (Section 6) list fault codes and LED error codes. Post a picture of the A5 PCB (its the one on the right side of the scope as you look at it) and a more detailed one of left side of the A5 PCB if it has SMD capacitors instead of normal through hole versions.

author: chilternview
author_rank: Frequent Contributor
timestamp: September 24, 2025, 12:35:54 pm
content: Definitely check J119 power supplies - it's not worth looking at anything else until you can confirm they are within spec, beware when replacing caps in the PSU that two in the PCB layout are swapped in error, if you get them wrong you'll get an exploding cap (see Dave Jones' youtube video on fixing a 2465B).Then as Kwakerman says check that the smd electrolytics on the A5 board haven't leaked and destroyed tracks.It looks like you have a vertical trace, you could have a dead U800 but no point worrying about that until you've checked the above.

author: Manolo Mos
author_rank: Contributor
timestamp: September 24, 2025, 09:11:34 pm
content: Hi. C1132 and C1115 are wrong typed on the pcb, where must say C1132 is C1115 and viceversa so, maybe you place the capacitors following the manual, if it is so, they should be swapped.

author: ThatElectronicsGuy
author_rank: Newbie
timestamp: September 27, 2025, 10:17:22 am
content: GuysFirst of all yeah I knew about the wrong placement on the shematic of these two caps. Second of all it works.At first I have checked measure points and all of them were wrong so I was pretty confused, but then I realized that one pin connector have broke when I was assembling and maybe there is no connection. It was exactly the case. I soldered it and now all the measure points are within the specs. Scope turns on goes through the self test and shows test 04 fail 12. After that I press A/B button and trace is there BUT It is blinking and I don't think it should be like that. Maybe you know how I can improve that?Ill send you pictures and video in a link.https://drive.google.com/file/d/1R0CzRUgWvIS_Dk_dKftCe5EEoYQcALRZ/view?usp=drive_link

author: tggzzz
author_rank: Super Contributor
timestamp: September 27, 2025, 10:28:02 am
content: Quote from: ThatElectronicsGuy on September 27, 2025, 10:17:22 amRTFM. What does that say about those points?What is the timebase and hold off settings?Turn off the readouts.

author: ThatElectronicsGuy
author_rank: Newbie
timestamp: September 27, 2025, 10:37:56 am
content: It works, nevermind thanks.

author: factory
author_rank: Super Contributor
timestamp: September 27, 2025, 11:40:01 am
content: Quote from: tggzzz on September 27, 2025, 10:28:02 amSeems to be two errors for calibration data, I'm surprized it doesn't show the dots/question marks in the blank spaces of the readout.David