Mnementh, you owe me a beer. Remember that Tek 2465 for sale local to me? Well...it's now mine. As promised I waited almost 2 weeks and decided this past Wednesday to toss them an offer. They wanted $75 USD for “non-working”. I offered $50 USD. They counter offered $60 USD. I accepted the offer. Picked it up today. But the best part follows....
When I got it home I discovered why it wouldn't power up. The screw on cap for the fuse holder as well as the fuse were missing. I don't have a spare so I took it off my 2465 DMS. Installed it and stood back and hit power on. The scope came up with all self tests pass! The pix shows it currently on the cart going thru a burn-in. The only anomaly I've noticed so far is that the sweep cal is a little off. Other than that it looks real good.
I'm going to let it cook for a while then give it a good cleaning. I'll have to order a fuse holder as I don't have that type in my spare parts bin. Does anyone have a spare knob for the Readout Intensity that they would be willing to give up? Right now I am happier than a pig in shit. A fully functional 2465 for $60 USD. Can't beat that!
The fact those particular parts are "missing" suggests to me they were robbed off this one to fix another "better" 24xx scope; you want to go over it with a fine tooth comb as they are a pretty complex beast and it may be an intermittent fault, or maybe one of the channels is hinky. Under any circumstances, getting it back to life so quickly is certainly promising; I don't want to jinx ya, just warning you to double and triple-check yours.
When you take the DC-DC converter out to inspect the caps, you'll have to remove the squirrelcage fan. It can be a total assache as hey use a shaft adapter that works like the collet-type RC airplane prop adapter above, only it's half aluminum (the threaded rod/nut you can see) and half made of plastic that is old and brittle and just looking for an excuse to break.
Do NOT attempt to loosen it by turning the aluminum threaded shank with a screwdriver! This is about guaranteed to break the adapter. I got one off successfully by removing the nut completely then warming the middle of the squirrelcage and threaded aluminum shank with my heat-shrink gun, then gripping the body of the squirrelcage in and pressing the threaded shank in to release the collet; that only worked on one of 3 that I have. An air rework station set to around 600 degrees F with an 8mm nozzle should work similarly and give you a chance.
You'll want to clean and oil the fan motor; on both of mine I used light synthetic oil with PTFE (Current bottle is called "Sonic Super Oil" bought off fleaBay) made for oiling rollerblade/skateboard bearings. This is a Hall-effect controlled brushless motor, and the bearings are inside. Once you have the DC-DC converter out, prop it up on end with the motor shaft up. Saturate the exposed shaft with light oil as described above (NOT WD-40 or 3-in-1; these are penetrating oils and will destroy the bronze bearings), work the shaft back & forth and spin a few times by hand, then let it sit overnight propped upright to allow the oil to seep into the rear bearing area that you can't reach from the outside. Wipe the excess oil off when you get up in the morning and spin the shaft, it should be noticeably smoother and easier to turn; you may even be able to distinctly feel the rotor "stepping" as you turn it. This is normal.
Also,
check all the DC rails that noise/ripple is within spec; these 'scopes are pretty fault-tolerant, so just because it passes POST doesn't mean the internal power isn't noisy as hell. My 2230 is a prime example... it has crazy noise on the 5V rail but it still works and has a nice trace, and it gets through everything on the POST except the LAST test - the high-speed acquisition RAM write test - before it throws a code.
Here's links to a
pdf parts list, a
pdf dissertation on rebuilding the Tek 24xx DC-DC converter,
a page that helped me with links to a lot of other useful info on repairing the 2465, and here is
KO4BB's archive of service manuals and resources for the 2465B/2467B. Please don't forget to give back a little via the button; hosting those documents isn't free and you can skip Starbucks or McD's for a day.
Also inspect the electrolytic caps on the A5 board while you're checking the NVRAM battery; they're known for leaking and damaging traces.Right now I am happier than a pig in shit. A fully functional 2465 for $60 USD. Can't beat that!
If I wasn't happy for your win, I could really hate you right now.
Congratulations.
Well, you can hate me then, I guess; it's already my fault.
To add insult to injury, guess what I have on my bench waiting to go in a little box along with some other random junque?
That is, if med6753 confirms they are the ones he needs.
In other news... When Windoze ATTACKS!!!
I kindof fell off the internet for a few days after the Windoze Spring Update forced me to allow it to install itself, then immediately proceeded to blow up my PC. How do you troubleshoot when it suddenly refuses to accept any input from ethernet, mouse or keyboard the instant control is handed off from BIOS? I couldn't even get it to boot in safe mode: tried a dozen mice/keyboards, even a couple PS/2 ones I keep for when I have to deep-dive embedded Windows XP on Point Of Sale & Info Kiosks. I've been working from my old win7 laptop and my phone since Monday.
After pulling my hair out for several days and numerous attempts, I finally successfully recovered from a restore point just before the attack. Now I can get back to work and play as per my normal state of abnormal.
Cheers,
mnem
It's hard work, but hey... I have a lot of Karma to burn off. };=)~~~~<