Tektronix 2213a trace problem - Page 1
Forum section: electronics / beginners

author: Xion
author_rank: Contributor
timestamp: August 28, 2015, 04:29:34 am
content: ? Maybe but maybe not...Let me start out by saying, its a Tektronix 2213AManaged to get it and a set of leads shipped to my house for less than $60 USDNow for my stupid newbie problems...Seems to work, get a trace on the screen but... the trace does not go all the way across the screen? I'v seen other 2213A's and the trace seems to go all the way across the screen. I'm just getting into using the thing, slowly learning to use it and what not. So any help/advice would be great!Yeah i'm sure i'm missing something obvious, or something i'm going to feel stupid for not doing... But hey! I'm still learning!

author: john_p_wi
author_rank: Regular Contributor
timestamp: August 28, 2015, 04:51:35 am
content: Knob with horizontal arrows, upper right that says position....

author: Stormchaser
author_rank: Newbie
timestamp: August 28, 2015, 06:01:33 am
content: Just wanted to throw in a picture for reference. Sorry for the quality of the pic, this was a quick "run to the garage and take a pic with your phone" picture, but hopefully it's helpful. This is the horizontal position knob on my Hitachi V-212 analog scope. You'll be looking for something similar to this. Not only will it get your trace fully on screen, but it will help if whatever you're probing doesn't line up with your grid and you want to count frequency or something like that.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: August 28, 2015, 02:08:46 pm
content: Congratulations on your purchase of this fine Analog scope, which is a perfect choice for the beginning scoposcopist.Try adjusting the Horizontal Position knob as indicated in the photo below. The index marker on the knob should be near center travel when the traces are fully across the screen, as shown in the photo. If this is not the case, there _may_ be something wrong with the scope.I'll be happy to help you check out and learn to use this oscilloscope. It is a "basic" analog scope but its delayed timebase feature really adds to its usefulness.

author: Xion
author_rank: Contributor
timestamp: August 28, 2015, 03:41:26 pm
content: I tried that first thing, but it still stays sort... I'll try it again when I get home and take some pictures... thanks so much for being patient with me!!!!

author: edavid
author_rank: Super Contributor
timestamp: August 28, 2015, 04:11:33 pm
content: 1. Make sure you take clear photos of all the control settings2. Change the subject line to something like "Tek 2213A short trace problem"

author: alsetalokin4017
author_rank: Super Contributor
timestamp: August 28, 2015, 05:48:31 pm
content: Hmmm.... there doesn't seem to be anything I can do to mine to make the traces "short" except turning the Horizontal Position control. So you may indeed have some fault happening.

author: Xion
author_rank: Contributor
timestamp: August 28, 2015, 05:57:26 pm
content: We will see when I get home x.x I already know I had it set wrong, thinking about it... oops! I'm praying it's just that, and not downing wrong with it. I mean... I'll fix it, but still. I'll be posting pictures of it, the controls, etc. When I get home. After I fix my mistake on the settings and see if it's still doing it. Again, thank you all so much for any help!

author: Redcat
author_rank: Regular Contributor
timestamp: August 28, 2015, 06:31:08 pm
content: I have only a 2215A, but should be pretty similar to your 2213A....Try to probe the test signal and set all the knobs and switches similar to the next picture.Then try as suggested to rotate the "position" knob. The trace is a little longer than shown on the screen, so it should not be short.Result should be something like this:If it is really short, it could be anything from out of calibration (if nothing is really broken, it is not that hard to get it to a usable state with the help of the pdf manual...) to broken or bent plates due to shipping or something with timing (trace jumps back too early) or you are in horizontal mode B (second time base) and so on... . We don't know yet.Please post some pictures when you are testing later at home;). Would be very interesting.Happy testing and Good luck

author: alsetalokin4017
author_rank: Super Contributor
timestamp: August 28, 2015, 06:43:33 pm
content: 2213a does not have the "B" timebase and trigger, so it can't be that.

author: Redcat
author_rank: Regular Contributor
timestamp: August 28, 2015, 08:57:14 pm
content: Ah, okay thanks. I was pretty sure they are similar ...so one possibility less whats wrong. I should have looked at the image of the 2213a.It has "no delay" or "delayed" switch ...hmm..maybe he is watching only a delayed "portion" of the trace...this is what i meant (one of many things it could be).

author: w2aew
author_rank: Super Contributor
timestamp: August 29, 2015, 12:46:55 am
content: Quote from: alsetalokin4017 on August 28, 2015, 06:43:33 pmIt doesn't have a B timebase, but it does have an intensified delayed sweep with an adjustable multiplier, so he should certainly check the Horiz Mode is in the No Delay position.http://www.controlelectronics.com.au/used/tek2213a/2213a-controls.jpg

author: Xion
author_rank: Contributor
timestamp: August 29, 2015, 03:26:25 am
content: Derp!!! Here you go! I forgot how to forums, apparently! I'm super sorry...For any wondering... That brown spot in the corner is some sort of glue, I think; i'm guessing they had something stuck their.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: August 29, 2015, 07:57:51 am
content: Quote from: w2aew on August 29, 2015, 12:46:55 amAs I said before, there isn't anything I can do with the controls on _my own_ 2213a that affects the sweep width or horizontal position _except_ the Horizontal Position control itself. And in the photo above you can see that "NO DLY" is set in the Horizontal Mode.But with the Horizontal Position control on my scope set as in the photo above, my trace isn't fully across the screen yet. With my knob index marker set to about the "P" in the word "POSITION" as in the OP's shot above, my traces end at the second graticule line from the right. With my knob index centered (index pointing to between "I" and "T" in the word "POSITION") the trace should fill the screen and be centered.However... in the photo above we can see that the trace is bunched up on the left side of the screen, and the pulse width isn't even and doesn't correspond to the timebase setting. (The probe calibrator should produce approx. 1 kHz square wave, and at 0.5 ms/div one full cycle should take up 2 horizontal divisions = 1 millisecond.) I think there is something wrong internally.You could try using Goo-Gone to remove the brown gunk at the top right of the panel.Here's what mine looks like at the same settings as in the OP's photo above:

author: alsetalokin4017
author_rank: Super Contributor
timestamp: August 29, 2015, 08:03:54 am
content: Note: If you can only find the Service Manual for the 2213 instead of 2213a, you will also need the SM for the 2215, because the V/div switches and the board they are on (most of the "front end") are like those of the 2215, NOT the 2213.

author: tautech
author_rank: Super Contributor
timestamp: August 29, 2015, 08:15:14 am
content: Quote from: Xion on August 29, 2015, 03:26:25 amSuspect Sweep non-linearity or Horizontal output stage as the visible fault cause.However start with PSU voltages and ripple checks as always with CRO faults.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: August 29, 2015, 08:36:56 am
content: FWIW:

author: Redcat
author_rank: Regular Contributor
timestamp: August 29, 2015, 11:29:17 am
content: It can be a bad transistor in the horizontal output amplifier section, i've seen that before.QuoteTry what tautech said.Soomething seems to be broken, it's not just the Position knob.Good luck.

author: DimitriP
author_rank: Super Contributor
timestamp: August 29, 2015, 02:07:41 pm
content: You might want to post a picture of the trace in the TekScopes yahoo group as well. Lots of Tek specific eyes there .https://beta.groups.yahoo.com/neo/groups/TekScopes/infoMy first reaction was I looked at the trace is that the coil at the neck of the CRT tube has shifted.

author: Redcat
author_rank: Regular Contributor
timestamp: August 29, 2015, 02:54:02 pm
content: There is..no coil. Most scopes have plates who are charged at a different voltage level instead of a coil. Of course, the plates could be bent. But I think it's most likely a fault in the horizontal output stage or the sweep signal. The scope tubes are often shielded, so it's not that easy to see all the plates.

author: Xion
author_rank: Contributor
timestamp: August 29, 2015, 11:06:17 pm
content: Thanks! I'll have to get to it tomorrow, for today is more work x.x i was so worried i was going to have to send it out somewhere!

author: AF6LJ
author_rank: Unknown
timestamp: August 29, 2015, 11:48:04 pm
content: Quote from: Xion on August 29, 2015, 11:06:17 pmLet us know what you find.

author: oldway
author_rank: Super Contributor
timestamp: August 30, 2015, 09:48:05 am
content: Check it in XY mode to see if horizontal amplifier is OK or not.

author: Xion
author_rank: Contributor
timestamp: August 31, 2015, 03:43:31 pm
content: Don't suppose any one would want to help me test this thing? I'm still learning and don't want to blow it up, or wind up killing my self probing something I should not probe. Better safe than sorry, right?

author: tautech
author_rank: Super Contributor
timestamp: August 31, 2015, 04:15:01 pm
content: Quote from: Xion on August 31, 2015, 03:43:31 pmStudy, study,study that's how I started.Understand basic CRO principles, it's not that hard.There is a massive amount of info in the Service manuals, IF you know what you're looking for.Simple signal tracing (backwards or forwards) will often find faults or at least the area where a problem exists, then either basic component testing or diagnostic skill will find the offending parts.The areas where one needs to be careful is :mains, PDA and deflection output stages.But as often the case with CRO's you'll need another scope to diagnose.But always post a link to the SM you are looking at so we can all be on the same page.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: August 31, 2015, 04:30:02 pm
content: Quote from: Xion on August 31, 2015, 03:43:31 pmCertainly better safe than sorry, right.It does take some degree of confidence to start prowling around inside an oscilloscope. The first things to check, as others have said, are the power supply voltages. Since you have a beam, you probably don't need to worry about the HV section itself (yet), and the low voltage supplies can be checked with a simple DMM. This isn't too risky. You will need to use an alligator clip to connect the negative lead of your voltmeter to the chassis ground. This keeps you from having to use both hands on probes; you will just carefully need to put the positive probe to the PS test points.I haven't been able to find a _free_ copy of the 2213a Service Manual, and as I noted before, the front end of the 2213a is more similar to the 2215 model than to the 2213 model, so you will need both SMs eventually. Then you can follow the procedure in the 2213 manual to test your PSU voltages. The manuals are too large for me to attach them here but you can find them easily enough using Google.Using the Tek SMs can be very intimidating if you haven't done it before, but the schematics are liberally scattered with test voltages indicated all along the paths, and it is often possible, with care, to track down faulty components on the boards using a DMM to check these voltages in a logical manner. However, this does take some skill and knowledge.So the first thing is to get the manuals, study the appropriate sections (figure out how to locate the board illustrations and schematic sections for the Power Supply voltage test points and the Horizontal Amplifier, for example), and then decide whether you feel confident enough to tear into the thing physically, or even whether it is worth your while.Also, posting the problem on Tek-specific websites just might turn up someone who has had the same problem and who can point you to a specific component or section that may have failed. This will cut the problem down considerably.ETA: FWIW, here's the 2213 Operator's Manual, small enough to attach here but probably not helpful as far as this specific problem is concerned:

author: Redcat
author_rank: Regular Contributor
timestamp: August 31, 2015, 04:53:23 pm
content: Nothing to add to alsetalokin4017s answer. Follow his advice.What you can do and always should start with, is measureing the basic voltages from the supply (i'm pretty sure they are ok, but do it). There are obvious testpoints on the board which say... "+..V", "-..V" ...many different supply Voltages have to be present.Maybe you are very lucky and can see a faulty component by eye if you know where to look (rarely, but sometimes you can see broken resistors, or burned components).Unfortunately i have only the schematics for my 2215A and not for your 2213A and I really don't know if the boards are the same.What you could do is, download the PDF with the 2215A service manual fromhttp://www.ko4bb.com/manuals/index.php?dir=Tektronix/Tektronix_-_2215Aand look if your boards look the same.You will find the PDF for the 2213 (non A) there too. The old Tek schematics are very good and detailed.The service PDF for the 2213 "A" isnot easy to get. But maybe a 2213A owner can post a link. You will need a manual.Get a basic understanding, how your scope works.QuoteRight. Just look at the board. For hours if you like. Without voltage plugged in. Study and compare.One additional question: when you have a very slow sweep speed (this way you can see the problem better), switch set to GND, the beam goes very fast in the beginning and then slows down right?Happy testing

author: tautech
author_rank: Super Contributor
timestamp: August 31, 2015, 04:54:25 pm
content: Quote from: alsetalokin4017 on August 31, 2015, 04:30:02 pmQuite right, but in most CRO's, the scope must be set to a default setup for these DC values to be valid.The decription of this process is not always apparent or easy to find, but is always in the manual somewhere.RTFM

author: AF6LJ
author_rank: Unknown
timestamp: August 31, 2015, 11:10:24 pm
content: Quote from: Xion on August 31, 2015, 03:43:31 pmPlease Don't take this the wrong way; Unless you get really lucky a project like that is way over the head of a beginner.Yes you can hurt yourself.No walking you through this over the Internet is not a wise idea.You need to pick a smaller less complex project to start with.

author: Redcat
author_rank: Regular Contributor
timestamp: September 01, 2015, 05:39:06 pm
content: Thinking twice about it again too...It really is a hard project for a beginner. It can hurt you. Without basic understanding it will be hard to solve, even with the blogs help, for you.As i said before, you can look at it unplugged for the beginning and try to understand the manual.If you feel not ready to repair it, don't do it.Buy another - working- scope. One scope is no scope.Do it later when you have more experience and feel ready - it is a keeper, repairable and definitely a very interesting project.Quote

author: alsetalokin4017
author_rank: Super Contributor
timestamp: September 01, 2015, 06:29:07 pm
content: I'm inclined to agree, at this point.Unless you can find someone on the Tek forums who has had exactly the same problem and can point you to the exact component to replace. It's probably not worth the time and effort to learn to use the SMs, to disassemble, troubleshoot, reassemble etc to get it working properly again.It's an advanced project. A fully functional 2213a should cost around 125-150 dollars US on Ebay. ISTR that this scope sold for 1,200 dollars (with 2 probes) in 1985 when it was first marketed, and that a refurbished and calibrated one still goes for 600 dollars from the major test equipment vendors today...

author: Xion
author_rank: Contributor
timestamp: September 03, 2015, 02:28:01 am
content: Yes, sadly... I knew that, a lot of people i know have warned me already any way, not to try fixing an oscilloscope untill im more experiened... I unerstand that i'm just starting out and thats a huge task to undertake as a beginner, but hey... In the future... I'll fix it and keep it! No sence in throwing it out, after all! That and i already found another one, its a 3 hour drive to pick it up, but i am getting a Tek 2215 i think he said, 2 function gens, and a bench top power supply. I really dont want my oscilloscope to kill me! I have so much i want to build! O:

author: AF6LJ
author_rank: Unknown
timestamp: September 03, 2015, 04:36:56 am
content: Quote from: Xion on September 03, 2015, 02:28:01 amThat is a good deal; take your time, learn and you will fix it.

author: Xion
author_rank: Contributor
timestamp: September 03, 2015, 01:23:16 pm
content: Found a working T912 for $30.

author: Redcat
author_rank: Regular Contributor
timestamp: September 03, 2015, 05:11:55 pm
content: QuoteVery cool. It's ancient. A 10MHz one right? Lets hope it really works.I think for the price you can't go wrong (ok..if you can get a "working" 2215 for a good price too, get the 2215) and it may be worth even more than 30 bucks. At least what i've seen on ebay recently. Not scope time at the moment, high prices.When you get more experienced, you will buy a more modern, faster one. But for the moment i would take it. It won't be the last one.At first I wanted a scope...and now I have 4.If you take it, please post a photo of it.Tom