TDS754D Repair and upgrade

TDS754D Repair and upgrade - Part 1

Рет қаралды 10,364

Күн бұрын

I've been trying to get a 1GHz scope and I ended up buying 4 of them - In this video we're looking at the TDS 754D, which is a 500MHz scope that can be upgraded to 1GHz.
Unfortunately I need to repair it first.
For more information on the upgrade procedure, check out this post:
www.eevblog.com/forum/testgear...

Пікірлер: 37

@ovalwingnut 5 жыл бұрын

Outstanding. Thank you

@MUHAMMADYAWARIFRAHEEM 3 жыл бұрын

Very informative video

@tgsoapbox 3 жыл бұрын

Thanks - Glad you enjoyed it.

@keithnoneya 7 жыл бұрын

That was a very nice video on these scopes. I have a 620B & a 744A. I'm hoping to fix them both. The 620 has a bad ch4 and the 744 has no display on the CRT but the aquisition and diagnostics all pass when I use the VGA on the back. I'll probably just replace the CRT with an LCD & Splitter I purchased for this, but haven't done it yet. Actually played with it a little this morning but until I get everything worked out I won't publish anything more on the LCD conversion. Thanks for the cool video. Best Wishes n Blessings. Keith

@tgsoapbox 7 жыл бұрын

Glad you found it interesting.

@matiasbriar3056 2 жыл бұрын

you prolly dont care at all but does someone know of a way to get back into an Instagram account? I stupidly forgot my account password. I would appreciate any assistance you can offer me!

@novarowen2649 2 жыл бұрын

@Matias Briar Instablaster :)

@matiasbriar3056 2 жыл бұрын

@Nova Rowen Thanks for your reply. I found the site on google and Im waiting for the hacking stuff now. Looks like it's gonna take quite some time so I will reply here later with my results.

@matiasbriar3056 2 жыл бұрын

@Nova Rowen it did the trick and I finally got access to my account again. I'm so happy:D Thank you so much you saved my account!

@PelDaddy 7 жыл бұрын

Nice scope. Love the RGB filter/shutter. You should probably research backing up and replacing those Dallas chips. Not sure about this scope, but older scopes like the 2465A loose very important factory internal cal data that is hard to get back. Interesting prerelease windows build you have there...

@tgsoapbox 7 жыл бұрын

From reading around the only thing that the NVRAM contains that can't be recreated by the scope (through self cal etc) are the options. There are a bunch of sites that show how to set the options (do web search for TDS PITBULL).

@PelDaddy 7 жыл бұрын

Ah, cool. So long as you have some kind of plan for when it fails. Looking forward to part two.

@tgsoapbox 7 жыл бұрын

Thanks - Right now I'm trying to get the scope to error out showing the specific IC that the problem occurs in. I can't find either the 754D Component Service Manual (which would have the address information in it) or someone who knows what IC that address relates to. Once I can find that then I can get to the point of removing and replacing the SRAM. Those are still available from DigiKey.

@amirb715 6 жыл бұрын

As for the Lecroy scope, you need to combine 4 channels to get the full sampling rate of 4GS/s or combine two channels to get 2GS/s but NOT the 1GHz bandwidth. The 1GHz analog BW is always there. Otherwise you get 1GS/s and measuring the fast rise time should still be possible on a fast time base setting.

@tgsoapbox 6 жыл бұрын

Thanks - The issue I had was that combining the channels required an adapter that simply wasn't available anywhere - The common ones that are on eBay etc weren't correct (I bought one just to try it out).

@hoiwong6772 5 жыл бұрын

Sorry to tell you about this 2 years later. Just saw your video. If you see a waveform in one of the channels twitching like this, chances are that the relays is the attenuator hybrid making marginal contact (the gap became a capacitor, which might vary due to heat or motion). Sorry to see you ruined the otherwise good acq memory section by ripping the pads (it's a red herring. the symptoms of bad acq memory is actually the problem you see after ripping the pads: you get random spikes because one or two bits after the ADC is not processed correctly and the graphing software is interpreting corrupted data.) I did exactly the same thing like you did when I first mucked with TDS scopes nearly a decade ago.

@tgsoapbox 5 жыл бұрын

Thanks. Great information on the issue, thanks for posting for others so they don't make the mistake that I did.

@user-fi3dd3oy1k 6 жыл бұрын

hello very nice vlog, just a question: how do you get the keysight connection expert software to work, just download? i use inside software from tektronix (dos)to analyse the problem and change the option inside the units. but this look very good. can you give more info. for expample GPIB adapter model..

@tgsoapbox 6 жыл бұрын

Thanks - I was using an Agilent 82357B USB to GPIB adpater - To get the IO Libraries, you just download them off the Keysight website. No license/keys etc required.

@gerryjamesedwards1227 6 жыл бұрын

Just for interest, I've seen a guy on YT who managed to verify the sub nS rise time of the Jim Williams avalanche pulser from AN47 on a 2467B with its MCP CRT.

@tgsoapbox 6 жыл бұрын

I sort of failed with this scope and lifted a track trying to repair it (from memory) - I just picked up a 53310A and was reading that you can use it to do sub 1nS rise time analysis by setting triggers at the 20% and 80% up and down then measuring the time interval - I need to try that out to see if it's possible. Thanks for the comment and I hope you enjoy the videos.

@gerryjamesedwards1227 6 жыл бұрын

Sorry to hear that. Did you get your measurement in the end with one of the other 1GHz scopes in the end?

@tgsoapbox 6 жыл бұрын

Thanks - These things happen, I'd just prefer if they didn't happen right under the memory IC on top of the parallel address bus - I ended up getting and repairing a HP 54845A 1.5GHz scope and got what I needed done, though to be honest the user interface on the Tektronix scopes is way better (in that era, don't know about today).

@nhokboqn123 2 жыл бұрын

its lovely

@tgsoapbox 2 жыл бұрын

Thanks for the comment - Appreciate it.

@bobbauvian7700 2 жыл бұрын

very details. nice . thanks. if I had one of these I would be viewing this video several times and listening word by word. I just bought a TDS3054B but I ran the diagnostic on it and it failed the acquisition so waaaaaa. anyone know what could l be causing it. the manual says main board. but you know... is there any other real fixes?

@tgsoapbox 2 жыл бұрын

What I've seen work is to clean the IC holder for the acquisition IC (if there is one, I might be confusing this with the HP scopes) - Otherwise you might want to inspect the solder joints on the front-ends and the A/D to see if any need to be updated. Have you checked out groups.io/g/TekScopes2 to see if they have any suggestions?

@bobbauvian7700 2 жыл бұрын

@@tgsoapbox thank you for your reply, whoever I asked, said this is a major problem don't touch it. so I returned it. If I spent a couple of 100s I would mess around with it. when I am spending 1200 which is a good deal for this scope, I want a working scope.

@yenaurapourtoulmonde 2 жыл бұрын

That LCD shutter was not their best idea cause the overdriven CRT ran out pretty fast. So was ergonomics: menus suck...An IT guys oscilloscope.

@tgsoapbox 2 жыл бұрын

Completely agree but I do wonder if it was just a sign of the times - Right now we have multi-color LCD panels and I find they're great but back in the day I preferred more resolution and a single color.

@tgsoapbox 2 жыл бұрын

Also I never ended up fixing this thing - Sold it to a Tek guy who did.