Tektronix 465 - Page 1
Forum section: electronics / repair

author: mass
author_rank: Newbie
timestamp: May 17, 2022, 01:50:24 pm
content: Hello. It is possible to purchase this oscilloscope for ridiculous money, but it has a problem (there is a photo). As the one who is trying to sell it says, he "got it by inheritance." And he doesn't know what happened to him. Writes what: -The oscilloscope turns on, on the screen when it is turned off, there is a bright green dot. So I have a question for experts in electronic business. What can happen with this device? It's a shame if it is sent for analysis and the device disappears. And so there is a chance to fix it. I would like to ask your opinion, dear masters, whether it is worth taking it for $ 80.Best regards Minsk

author: PaulAm
author_rank: Frequent Contributor
timestamp: May 17, 2022, 06:37:08 pm
content: Probably the filter caps have dried out. This is a fairly common problem. The metal can caps have 3 ground lugs and one positive terminal and Tek used the can as a jumper on the PCB. You can replace them with 105C snap caps and use an adapter board to match up the footprints between the cap and the PCB. You can find them on ebay and there are images/gerbers floating around the net. You need reasonably good technique to desolder the old caps without delaminating the traces from the pcb, but it is not too horrible.Another issue that it might be is one of the bridge rectifiers failed.Since it obviously need repair, I wouldn't offer more than $40-50, but that depends on where you are.If you get the scope, check the ripple and voltages of all the low voltage power suppllies, that will point out the issue.It's a nice scope; Tek sold zillions. As many people will likely point out ad nauseam, it's not a DSO, but it is still useful along the lines of a one eyed man in the country of the blind and all that. I have one and use it from time to time.

author: mass
author_rank: Newbie
timestamp: May 17, 2022, 07:07:41 pm
content: Quote from: PaulAm on May 17, 2022, 06:37:08 pmI don't have access to ebay. But if there is a European analogue, then why not try. It would be nice to find a circuit diagram. I can't test it when I buy it. In our region, there are few Tektronix oscilloscopes and it will be difficult for me to find specialists who know their problems. But I would like to fix it myself. And be glad that I was able to do it. I know how to use a multimeter. I can find what comes from where. And the seller does not want to throw off his horns, like a bull, on a red rag, he wants to break the jackpot for a non-working device Sorry for the google translate.

author: MikeK
author_rank: Super Contributor
timestamp: May 17, 2022, 08:39:56 pm
content: Service manual, right from Tek:https://download.tek.com/manual/070940300.pdfInstruction manual (some schematics in this):https://download.tek.com/manual/tek-465.pdf

author: mass
author_rank: Newbie
timestamp: May 18, 2022, 03:51:57 am
content: Quote from: MikeK on May 17, 2022, 08:39:56 pmThank you !

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: May 18, 2022, 01:08:12 pm
content: I could have bought two of these in need of repair for $10 each in the USA, just last month.Working ones are maybe $100-$200, a real good one would be more. But prices are going up.I have a 475, 200 MHz, almost the same thing, these scopes are the "gold standard" for good old analog scopes.Other brands are far more common in Europe.

author: mass
author_rank: Newbie
timestamp: May 18, 2022, 01:14:59 pm
content: Quote from: Wallace Gasiewicz on May 18, 2022, 01:08:12 pmSo I would buy it too. but the person who sells, he also raised the price for this faulty device. And it is not clear even what he is guided by. The device is faulty, but it turns out that money is more important to him -)))I wouldn't mind even buying it from overseas, but shipping to the other side of the globe would be huge. And it turns out that it is not very profitable to buy. So I'm trying to take my first device but it doesn't work.

author: jonpaul
author_rank: Super Contributor
timestamp: May 18, 2022, 05:22:48 pm
content: bonjourYour location or country may be useful infoThese 1970s scopes have very good design but the capacitors and high voltage CRT section and transformer start to fail.Repair and maintenance are not trivial and can be dangerous as mains, and high voltage is involved.If you have a ham ( amateur) radio flea market thats the best placeWe have bought several Hameg German scopes 1980s vintage in perfect condition for 5...25€ at Marché au Puces in Paris.Depending upon your location you should wait....Finally buying and shipping scopes around is risky as few sellers can test them out or pack properlySee both EEVBLOG and Tektronix scopes at groups.io for many broken CRT stories, most recentwas a tektronix 576 curve tracer.Bon courageJon