EEVblog 1515 - Dumpster Tektronix TDS540D 500MHz Oscilloscope LCD Upgrade

Part 2 in the dumpster Tektronix 4CH 500MHz TDS540S oscilloscope.
Replacing the CRT with an LCD had a few issues...
Ebay listing here: www.ebay.com.au/itm/225251897379
Part 1 dumpster find: • EEVblog #1185 - Dumpst...
Part 1 Repair: • Tektronix TDS540D Repa...
Forum: www.eevblog.com/forum/blog/ee...
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[@EEVblog]

The results of a poll on Twitter said to move this video from the 2nd channel to the main channel here, so here it is.

[@scottbattaglia8595]

Geez, you always find awesome stuff, I been saving up for an oscilloscope for a a year and I got like $400 saved up, you got any old scopes you want to sell? I do need a digital channel at least 1 lol but for real, seriously help a brother out," I obviously am interested will pay for it" but let me know if you got an old scope with no use....

[@scottbattaglia8595]

I like that deal, at least it won't burn up, but hella frustrating if you don't know though.....

[@sarahjrandomnumbers]

Certainly seems more like a 1st channel video. :)

[@JH-tc3yu]

lmao the irony of polls on twitter becoming the most important thing in the world a few days later...

[@RingingResonance]

On eevblog, some brilliant people were successful in converting these older scopes into the better models via some 0ohm resistor settings, adding some chips on the video side, and changing some thing on the acquisition board to get full 1ghz bandwidth. I helped make the change necessary to use the NuColor CRT's and their respective driver boards. I even managed to use a B&W CRT to replace the original NuColor CRT after cutting off the LCD shutter, making a CRT adapter, and modding the case a little bit to fit the slightly longer CRT with the LCD shutter in front of it. More recently, I made a 'copy' of the flyback transformer for another project that needed one. I had several of the CRT driver boards and one with a bad flyback transformer I was able to remove the core from. I measured it's dimensions and designed a spool that can be 3D printed, wound, and then placed into a new case. I haven't used this for replacing any of the flyback transformers in any of my scopes, but I did use it for driving a 5FP7 radar tube. Worked really well after figuring out how to properly insulate the windings.

[@mickeyfilmer5551]

Every video is a learning curve for me and I'm in me 60's. -so Dave proves that you're never too old to learn.

[@johnwest7993]

I need to park myself in front of your dumpster. Although I've done pretty well over the years in the dumpsters here in Boulder, Colorado, USA.

[@rossdimitrov]

Was gonna ask about these dumpsters. Mate, I've worked in tech companies for the past 20 years and never ever have I found a scope in the dumpster. I'm sooo disappointed. I knew I should have moved down under

[@martinkuliza]

Boulder huh, The home of stephen king Question, is there REALLY a STANLEY HOTEL in Estes Park ?

[@thomasesr]

The reason that this scope had that failure mode is because it is a DIVA scope, which means that it needs a Fan to work.

[@RetroJack]

🤣

[@H-77]

TDS500, 600 and 700 series are all divas in general...

[@johnwest7993]

I always plug in the fans these days when I have the boxes open, because the fans are critical components to keep expensive devices from blowing up in modern gear so the designers make sure the fans are working during their power-up self-tests, and it's a piece of cake to monitor fan current these days.

[@eebaker699]

Definitely don't want to burn up the custom CCD's on those older Tektronix oscilloscopes.

[@MicheIIePucca]

I used a black felt marker to color a LCD frame in an arcade cabinet and it was behind slightly tinted glass. A black felt works well just to hide it.

[@florianhofmann7553]

I have upgraded my TDS724A, which had a colour CRT, with the same screen and also had to adjust the clock setting for it to work. I used a LM7812 bolted to the chassis to drop down the 24V CRT supply. I also backed those Dallas NVRAMs up via GPIB. Feels like home seeing Dave work on something this familiar. Have a good one everybody!

[@RingingResonance]

GPIB commands realated to the error log on TDS series scopes. errlog:first? errlog:next? errlog clear

[@RingingResonance]

yt deleted my other reply............................................................................... Probably because I mentioned a certain dog breed as it's the password to the GPIB command system for enabling/disabling features. Said password is one word all uppercase. Here's the commands. WORDCONSTANT:ATPUT 327686, 1

[@florianhofmann7553]

​@@RingingResonance Awesome one more incentive to get a GPIB interface.

[@RingingResonance]

@@florianhofmann7553 They make USB ones which is what I used. On the cheapo one I bought the software interface that comes with it is very simplistic/basic and not quite intuitive to use. You pretty much have to type in the raw data/commands and then read back 1 line at a time.

[@florianhofmann7553]

@@RingingResonance Thank you once more 👍 I already have a National Instruments PCI card and most options activated. But for someone who thinks about buying or already has one of the TDS scopes it is good information, that he can upgrade options and easily backup the NVRAMs with "unified tektool" using GPIB.

[@GapRecordingsNamibia]

I think Dave could use a 3D printer in the lab, a printed bezel would stop the metal from the LCD peaking through and would give you a means of securing one part to the other, and believe me once you have a 3D printer you start making up ideas to use it for.... Very handy they are......

[@EEVblog2]

Sure, but I'm not keeping the scope, so not worth the effort.

[@MattAtHazmat]

Years ago (~2000), I had Tektronix "upgrade" the memory on my work TDS784D. It was just a software unlock of memory already installed.

[@systemloc]

Yeah!! Been waiting ages to see you do this hack!! Glad it's on the main channel, I may have missed it. Thanks for taking this on!

[@derekfoulk4692]

People like these types of scopes because they actually have soul. Older, full of cool chips and does everything you would ever need. Btw the manuals for this thing dates back to good old 92'!!

[@ehsnils]

4:36 - those Dallas modules are actually potted an ordinary chip with a 3V Lithium coin cell and they can be "hacked" by cutting open the +3V and ground positions on the chip, cutting one of the leads to the old battery and then connect an external coin cell battery. I have done that with a Compaq 386sx computer and it worked great. I found the instructions on the net somewhere like 5 years ago or more and it was actually quite simple to fix it. The potted IC just have those battery legs bent upwards inside the potting.

[@PhonePhreak3z]

Great video would love to see more modification/repair videos Dave!

[@bluefoxtv1566]

Nice little upgrade. For a bit i was confused as to why you did not use the power from the fan. But then you showed the fan and it was 24 Volt.

[@pradeepramgobin4904]

love your sense of joking humerous

[@McTroyd]

+1 vote for a Safe Operating Area scope video! I had never heard that term used in that context.

[@leandrolaporta2196]

Green!! Absolutely!! I love it

[@danielmorrison7579]

Print a bezel with a 3D printer. Also print the holder for the LCD board.

[@eh42]

Nice upgrade. I just replaced the 510K resistors driving the focus of my Tektronix.

[@teslastellar]

You found this in the dumpster? Where's this dumpster so I can go do some dumpster diving too?😃

[@EEVblog]

kzbin.info/www/bejne/j4mTfn2gpp6Aq7c

[@organiccold]

I was wondering what has happened to this Scope! Good to see it back to life :)

[@sneugler]

As a note for anyone working on the later versions of TDS models (600, 700, etc.) with 4 ASICs on the acquisition board, they absolutely need airflow over them while powered up. They love overheating otherwise and can be damaged.

[@RingingResonance]

The case is necessary to get that proper airflow. If operating without the case you need an additional fan blowing across them.

[@JurassicJenkins]

@3:13 Poor diagnostic workflow when the fan isn’t included as a failure point. Sucks even more when $$ are dropped on a processor board and the issue still exists. Great video!

[@EEVblog2]

Yeah, should have been in there as first step.

[@lrrromicronpersei8294]

Nice to see it up and running, maybe you could find another youngster to donate it to like the one you purchased at the sale Keep up the great work Dave

[@TechNed]

That was fun. Thanks!

[@roboman2444]

There may be an opportunity to push your own voltage into the backlight circuit and artificially increase the brightness. I would not be surprised if that thing can handle 11 or 12v instead of 9.8.

[@EEVblog]

Likely possible.

[@n2n8sda]

Glad you moved it to main channel, hadn't come up in my feed... I'm laughing at that fan issue.. I did EXACTLY the same thing on some other hardware a few years ago.. flow chart said "can you hear the fan" and I thought no I took it out as the bearings shot and it wasn't spinning, it's only a 2 wire fan I'll change it when the things running... .. a day later of testing I put a new fan on and the thing worked fine!!!! That "can you hear the fan spin" should come with an asterisk highlighting the unit wont work without one connected.

[@RingingResonance]

Also in certain DPO modes, these B&W scopes will show a color trace out the VGA port! I think it's if you set it to manual persistence in the trace menu.

[@waltschannel7465]

I have heard the same thing. I have a 520D that I want to play with in this regard but, the CRT is still in good enough shape that I'm not quite ready to purchase a VGA LCD display just yet.

[@jaycee1980]

I wonder what the LCD board actually does with that 12V - id' bet it is simply input to DC-DC conversion which will be stepping down anyway. 15V would probably work just fine!

[@MaxPivovarov]

yep VGA+AV lcd driver board KYV-N2 V6 Operating Voltage 9~16VDC

[@sivalley]

With all those onboard buck regulators i would think it would tolerate being fed from the 15V rail. . .

[@rodlophus]

I think you couldn't have chosen a better t-shirt for this one 😄

[@nophead]

Perhaps, rather than actively detecting the fans presence, it just needed the current it takes to keep the PSU from hiccuping.

[@PeetHobby]

"yup, just center that in there and just tape that in place, I think?" Bob's your uncle. 😁

[@tocaamerillo431]

Like 15 years ago I had a similar thing with a pretty nice mitsubishi projector that I got sold for basically a beer as not working, with the lamp being the main suspect and the electronics being next in line. Turned out the lamp was basically brand new with just a couple dozen workhours on it, and the cause was fan connector coming loose, perhaps being poorly put in from the factory or maybe some mishap during some servicing.

[@electronic7979]

Good idea 👍

[@Ahmedahmed-rj9ss]

great work

[@idkkdi8620]

I just noticed i havnt got any of your videos in my feed in over a year.

[@chirculescuhoria2676]

Whoow... It detects the fan !!!😁

[@yoksel99]

Nothing says late 90s more than that Java logo! ;)

[@Myrddraalfade]

In a similar scope I used double sided carpet tape to hold the 8" lcd in position.

[@Kellen6795]

Tbh I still want to see a crt repair video. Would be super interesting

[@bobweiram6321]

I have an old TDS 1012B and it has the old B&W display. I read someone converted it to color on the EEV blog forum.

[@jeffm2787]

The Green rocks! 👍

[@abitofabitofabit4404]

I think the VESA standard video timings (800x600 and up) use positive sync polarity to distinguish from legacy VGA 640x480 which uses negative sync polarity. Your installed VGA to LCD converter apparently ignores that.

[@andymouse]

Result !....cheers

[@imark7777777]

I bet they're using the incoming video signal as a clock source, and that clock source is also used to drive the menu… and that clock source is a little out of spec for what it's expecting.

[@ThebigFlanc]

Nice retrofit :-)

[@jeditoto3441]

Nice job Do you have a project in mind to replace a CRT with an LCD when there is no VGA or other video output. I am thinking about the old tek scopes for example. Would it be possible to use the outputs of the display amps for deflection plates ?

[@paulstubbs7678]

Wow, wouldn't mind that one in my kit, Oh Sydney, darn.

[@santi308]

Dave, i repair many led tvs and that problem of double/triple image is related to shorted clock signals on the lcd panel itself. Very common on samsung displays. Maybe it has an of-the-shelf fault in it. Please if you found those memo ics, put on them to make it full colour!

[@alhassanomran244]

Many thanks for the cool video. Can you share the link to the LCD you used in this upgrade? I need it to upgrade my Huntron Tracker 2000 as it's Power transformer is dead and I can't use it anymore.

[@Torogol85]

I watched this video in Odysee, Mr. Jones uploads them there first. I'm watching it again...

[@jlucasound]

I never thought you could replace a CRT with an LCD. So cool! What a "Brick", though. 🤣🏋🏋‍♂🏋‍♀ No wonder you won't ship it! Not worth it.

[@catalinalb1722]

Have a similar scope just without the floppy drive. I think the caps are liking since channel two isn't working

[@MadScientistsLair]

I have the predecessor to this series, the TDS744A. It doesn't have DPO but also no hard disk to worry about. Mine still passes SPC. If these fail SPC, replace all the relays on the acquisition board.

[@burnte]

There are a lot of creators that I watch at 1.5x and I love how Dave speaks fast enough that I don’t have to. He values our time and doesn’t fuck around!

[@TradieTrev]

hahaha good call!

[@zedcarr6128]

16:04 I suspect the thing to the left of the fan is a heated thermistor or something similar that detects air flow like the MAF sensor in an engine does. This would detect the fan not running, running slowly and if the vents were clogged.

[@nameredacted1242]

MY HEART BLEEDS WHEN I SEE WHAT THEY REGULARLY THROW AWAY AT MY PLACE OF EMPLOYMENT..................... AND THEY ACTUALLY PAY FOR IT TO BE HAULED AWAY!!! THE HAULER IS LAUGHING IS ASS OFF, HE IS GETTING PAID BOTH WAYS!!!

[@reasonablebeing5392]

design and 3D print a frame or gasket for the LCD display in black filament?

[@sparqqling]

You can get floppy disk to usb converts, replace the floppy disk drive to a special one with USB output. Some require the USB drive to be formatted at 1.4MB.

[@liviu-dantimar9492]

Yes for SOA!!! : )

[@mfx1]

Doesn't seem likely to me that the hard drive is just for storage, might be worth checking it out/backing it up if you want to keep this alive longer term.

[@MrDoneboy]

SOA video, Dave!

[@domtom128]

👍 And thermal impedance tutorial (thermal time constant calculations - extension of the thermal resistance video).

[@frogz]

okay, im jealous... i dont have a scope at all and you're finding them in the dump!

[@ChristopherLionRoars]

Can those boards be used for non vga get replacement. I have a kaypro 4/83 that needs an LCD. I assume it's timing is ntsc compatible. It has separate h and v sync signals.

[@EE_fun]

@eevblog are you affected by the flooding in NSW?

[@JAKOB1977]

If there is fx 15v then use 15v, often quite a margin to work with even though it claim fx 12v nominel for the display board..aint there often some wiggle room on these modern products, and you can easily check how it being bucked on the display board and chedk the values vs the 12v scenario ..use your adjustable PSU and check it, while slowly dialing from 12v to 15v.

[@503jmn]

Ahh the Orca digital board!

[@oskimac]

Nice upgrade. Nice repair and nice scope. But please stop flipping that front flex

[@emptech]

You mentioned converting the floppy drive over. How successful has this been? I have a TDS644B. Great channel, but you knew that. Jim

[@monoamiga]

Show me where your dumpsters are! I wanna dive in!

[@JurassicJenkins]

@23:00 - Would it be ok to tap off the 15V rail with some diodes in series to drop the voltage to get close to 12V? I’m imagine the LCD board has some tolerance. That’s the first thing that came to mind. Please tell me if my concept is off. Thanks!

[@zitt]

Or just a LM7812 on the 15V line. I doubt the LCD takes more than a 12Watts at 12Volts.

[@Nukle0n]

3D printed bracket for the LCD?

[@X11R7]

Very pretty device. LCD upgrade OK but I think 2 upgrades for more quiet and modernisation : Floppy emulator drive for USB flash drives and IDE - SATA converter for SSD's. Mechanical IDE disks voice horrible. :)

[@ford1546]

Hello. Does the oscilloscope have HD images for better detail? How common are HD resolution oscilloscopes nowadays?

[@ToTheGAMES]

First question: No. Second question: Yes.

[@vencibushy]

Appears as it has enough space to fit larger LCD... or does it?

[@electronik808]

Hi can you dump the ram? I may have cleared the team of mine...

[@fixitalex]

Hey! What about CRT magic? Everybody like CRTs!

[@petersage5157]

Have another giveaway. They're always a hit and they're great PR.

[@notsogreat123]

These scopes will get very hot very quickly without that fan. Do not disconnect that fan !!! Even with the fan running the unit will overheat without the covers on. Also the 25vdc regulation is helped by that fan. The 25vdc over voltage is what is being detected.

[@goja52]

Whenever I had a problem with VGA it was because of SYNC-ON-GREEN.

[@dw1444]

i dont remeber this stream

[@alext8828]

I just replace the battery in my Garmin Nuvi 40lm and now the screen is dead. Any ideas?

[@ovalwingnut]

I approved this video - Old schOoL baby!

[@ehsnils]

If someone overseas want this scope they'll have to come to you and get it.

[@70lucatz]

The VGA Board has a 18V BUCK Converter on it no need to add external BUCK. The 540 has 15v points that can be used

[@listerdave1240]

I think the fan thing is simply a matter of the power supply being unstable from being too lightly loaded rather than it actively detecting its absence and aborting the startup.

[@H-77]

17:58 - NOBODY could have seen that coming.

[@gandalf87264]

All this fancy colour stuff.... All I want to see is a wave form.

[@julians7268]

How do you find these in a dumpster? Dang.

[@cberge8]

You should have 12v and 5v powering up the floppy drive.

[@jaycee1980]

Not neccesarily... there are plenty of 5V only drives

[@simontay4851]

Floppy drives don't use 12V. Only need 5V.

[@jaycee1980]

@@simontay4851 Depends on the drive. Some of the older floppy drives do. Anything since about 1991 will likely be 5v only

[@zitt]

And the HDD i that thing is probably a mobile drive so needs +5 and 3.3V,

[@gerardzi7930]

But TDS series have CRT and note LCD how IS possible to upgrade ?

[@josephchamness9915]

Looks like if you wanted to buy one you would have to pay from 700 to 2000 AUD ?

[@johnwilliamson467]

PWM current sensing to determine running .

[@EZ-HACK]

nice dumpster find.... im making a cable that u can use a cordless drill Battery as a backup batt for a laptop. my i have been testing a few batteries and the results are amazing basic clip/probes to laptop power port 18volts D/C EZhack Batt Cord HACK lol now what cheap scope can tell me the noise coming out a 18-volt D/C lithium im not marketing it just making a video for Utube

[@bltouch2852]

no need mate

[@pomo7496]

买个12V电源，安全又好用。v主话真多

[@gandalf87264]

Damn it Dave. Just put the scope into the box with my address attached to it and throw it into the ocean. Maybe in 100 years or so it will arrive on a shore near me. On second thoughts, scrap that idea because I will most likely be dead by then and whoever does find it will probably think that it is a cute little TV set.

[@LawpickingLocksmith]

Next trip to Sydney every dumpster needs raiding?

[@kittyhawk9886]

Don’t know where these elusive dumpsters are. Every one I looked in had trash and smelt bad!