DR #7 - Tektronix 2205 Oscilloscope Troubleshooting and Repair

[@dpyles9396]

Its great that you included your mistake. Most would have edited that whole thing out. It was an excellent learning opportunity for us viewers as well.

[@mcac-youtube]

Hi, friend. I have a Tek 2205 GM, it´s a 40MHz modified version of 2205 20MHz. I bougth it brand new at 1993 here in Brazil. It´s yet a perfect scope, it helped me for all that years. I repaired it just once, when the hi-voltage of the tube disappeared, it was just a bad contact of a wire in that circuit. Thanks for your video. Sorry for my worst english...

[@dualityrepair4770]

Hi mcac2007. Glad to hear your scope is so reliable. I wish electronics built today were of the same quality. Also, your english isn’t bad at all. Most of us in the US, including myself, couldn’t write one sentence in Portuguese.

[@minilab9030]

Instructive mistake vis the radial electrolytic capacitor polarity. Thanks for helping making it easier for us to avoid the same mistake. Excellent diagnosis and repair.

[@jmannUSMC]

Oh man nothing worse than blowing a cap! I picked up a noisy 2215A that I finally have time to repair this summer. I had an idea of where to start but this vid gave me a bit more direction on where to look. Thanks a bunch!

[@Jarraknz]

You could have easily edited that capacitor mistake out but you didn't - thank you for that, it all helps us learn. I've made that same mistake. I've subscribed to your videos, looking forward to many more. Keep up the good work.

[@srtamplification]

Great video. BTW, I knew that those two caps were going to blow as soon as I heard you say that you were going to make sure that all of the negative sides of the caps were at ground. I was screaming at the monitor. Oh well it happens.

[@rodrigocastro2005]

There is a 90% chance that I would have made the exact same mistake even though I know exactly why they go reversed against GND. I learned a caution lesson today. Thanks DR!

[@bax737]

I’m learning a lot from your videos, including the mistakes! Thanks so much for doing these!

[@saarike]

Great repair! When you measured with dmm those negative poles for caps you put caps with this information and forgot that there was 2 negative rails caps with vice versa polarity.

[@MrDoneboy]

We should always learn from our mistakes. Even Dave Jones installed a cap backwards, and blew it on one of his vids!

[@PeterWalkerHP16c]

What was the frequency of the noise? That should be telling. It looks like the CHOP Mode Switching Rate. 500 kHz so I would have confirmed that and started there after checking the rails maybe. You can use the probe adjust output for a signal source. There still seems to be a lot of y jitter on the channels - at least on the video.

[@andrewverran3498]

Hi , I have a 2225 that has a sort of broken 3 way " X1 ALT MAG " ..do you have any information on a replacement or suitable alternative? PeaceFromOZ

[@dualityrepair4770]

Other than what you might find on Ebay, I do not unfortunately. Sorry.

[@MEBFlorida]

Thank you, this was extremely helpful.

[@VintageProjectDE]

Hi Nick, I just stumbled across your channel and your repair video. You're doing a great job there! Can we see more scopes? :) I currently have a Philips PM3217 on the bench, that I've been working on for the past month. Watching others' troubleshooting process helps a lot progessing my own repairs. And that mistake: Been there, done that. I think that happens to everyone every now and then. My solution: If there are no markings in copper or silkscreen, I just put a small '+' or '-' with a sharpie when removing the cap. The marks rub off when I clean the board with alcohol or PCB cleaner afterwards.

[@dualityrepair4770]

Hi Thilo, Thanks for the nice words. I love oscilloscopes, especially analog, so yes there will be more scope videos. Among other items, Im working on 2 scopes right now, although it looks like one of them has a CRT issue so that one is likely unrepairable. Good suggestion on the cap polarity too.

[@Musinformation96]

Ever calibrated this unit?

[@passtaudiosoundservice4866]

Share manual service hameg mh2005 sir 🙏

[@jermzonthebeat3730]

I have one of these but it’s just a dot no like at all nothing changes on anything just always the one dot can only going vertical

[@dwinsemius]

Is there much similarity between your 2205 and my SC 205? Do the trailing numbers indicate a design heritage?

[@dualityrepair4770]

I have no idea sorry.

[@boonedockjourneyman7979]

Because of the form factor and power supply differences it’s hard to find much in common. The SC series lacks most of the control inputs. The TM plugins use the most minimal circuits imaginable.

[@eliasragi7472]

Excellent tutorial, thank you. May I also ask if and how can the handle be removed. Thank you.

[@Musinformation96]

Ever calibrated this unit?