HP 54501A Oscilloscope Teardown & Repair

[@V0ngard3n]

I woke up in the middle of the night with this strange music and your voice , I literally felt like I was an android after some upgrades ❤ lots of Love from the Underworld

[@johannesparkmann3899]

Nice video, but god why that acid trip soundtrack in the background? I am now afraid of HP scopes

[@mbirth]

And you should be…

[@keeboudi]

Hahahaha

[@momo-dm3rw]

I like trips.

[@Damjanhd]

that soundtrack makes me cut my weins

[@GLAJMAN]

Jesus this video is so cool. This looks and feels like a repair shop from Blade Runner. I really dig the camera sounds while it focuses, it really goes well with the soundtrack. Good job on this video.

[@ArnaudMEURET]

Marco, please disregard the hundreds of complaints about the eerie background music. Just trust the five of us who testify that the mood is perfectly balanced for this journey into last century high-end electronics. I can almost smell the dust on the aluminum blind blades in the lab where this device was sitting on this hot summer late afternoon as the last Coulomb left this NVRAM battery.

[@ritvarsrizikovs7117]

Hello! I have exaclty the same oscilloscope and made NVRAM change also. It was not very easy, but with patience and good tools/settings I manage to get out old NVRAM without damaging board. I did not solder new NVRAM into board but solder some good quality DIP28 chip socket. Next time I need to replace NVRAM - I will just take it out and put in new one even without taking out board. My old NVRAM was DS1235YW (8912), but since its not in production anymore I bought from Farnell new DS1230Y-120IND+ (1804). Big fan was also replaced - its standart 12V 120mm fan - I replace it with Thermaltake 120mm fan and put some rubber plates under it to make it more silent. Calibration screen is a little bit different like in Yours, but result is the same. For Calibration You can just use 2 probes and stick them together :). Now I have this very nice Oscilloscope for my workshop up and running again - big thanks to You to intruduce me in this not very complicated, but very important procedure. Good luck in Your future projects.

[@mafan.stenole]

Just got one of these units, and while looking into troubleshooting the notorious NVRAM issue, I realized that the CRT might also be nearing the end of its lifespan. I’m curious to know if you’re still using yours after 5 years and whether you’ve noticed any dimming in the brightness. Thanks!

[@simonbrouillet6156]

Thanks Marco, I decided to fix my 54503a because your video inspired me. By the way, the bg music is perfect since real electronic freaks can get in trance when we dig deep into it.

[@siegmundeurades5753]

Going back to older Marco Reps videos is quite the trip. Especially with eerie music playing throughout the video

[@ViniciusMiguel1988]

When life was simple and Marco had a single bnc cable, the new Marco can't let the triax go 😁

[@alliefdxproductionservices5856]

This has to be my favourite of your videos. I will admit I've fallen asleep to it once or twice.

[@reps]

Don't dig up this old cringe material :)

[@GeorgeTsiros]

@@reps Are you kidding? This is one of your absolute best videos. The eerie ambience, your almost whispering voice, even the camera focus noises makes it seem like some retro-futuristic documentary or something

[@billquantrill4960]

@@GeorgeTsiros It is quite great. oh and its useful to boot.

[@stryder751]

the way it focuses and the sound of the camera you are using reminds me of the scenes in the original Blade Runner where Ford is using the computer to enhance the pictures he was looking through. Nice!

[@setSCEtoAUX]

The documentation of this fix is really excellent and deserves the thumbs-up, no matter what is thought of the music (I didn't mind it). Thanks!

[@chemistryscience4320]

So the secret advice is to Fix expensive equipment with scary background music, these helps you maintain precision. Nice Videos BTW :D :D

[@jaakjaak0427]

Love HP (the real HP, not the post November 1,1999 HP), but these scopes are what made people hate DSOs. Cool that you've fixed it!

[@eperksmedia]

Absolutely loved the atmosphere of this video.

[@Darieee]

Hmm, kind of stupid to have a 10yr life part NOT socketed ... I mean ... why ... Also - aren't there any of these with aftermarket battery holder mods? Is there a reason these chips don't simply habe BAT+ and BAT- pins?

[@Jeremy-fl2xt]

0. Yes, I know this video is 3 years old, but still it's interesting and worth commenting on. 1. The translucence of that PCB is awesome! It's so cool to compare the routing strategies of the day vs current strategies. Many component orientations appear to be Design For Hand Assembly rather than optimal routing or Signal Integrity. 2. The music is great, but perhaps a bit too poppy. Have you considered using a straight waterphone without the chime/bell? 3. A socket would be a great idea, as long as the stack-up fits within the chassis slide-in clearance. 4. This takes me back to using a similarly interfaced HP logic probe. Now you can get USB2.0 equivalent equipment of both in a single unit 5. Slide on SMA? WTF is the point of SMA if the connection is slide on? 6. What flux do you use that IPA is adequate for cleaning? I seem to have to use Acetone based stuff, lest I wind up like a cat with tape any time I touch the board...

[@josseman]

Awww, look at this, some cute little old MarcoReps.

[@YuriyKrivosheyev]

Thx, great. I do appreciate “Key ignored” message on UI :)

[@DoRC]

The repair witch project!

[@DoRC]

digitalradiohacker It wasn't really meant as a criticism. I liked Blair Witch project. However you are right. I have no one to blame but myself for stopping making videos. I really do want to pick it back up one day.

[@bdivi2000]

Why did you not use socket instead of direct soldering ?

[@DangerousPictures]

in order to easily replace the part if it fails again

[@jacekpaw1]

Very interresting video but I found the background tune a little bit annoying after 25 minutes.

[@reps]

Jacek Pawłowski Well sorry :) Maybe you find a little comfort in the fact that it's completely algorithm-generated?

[@uptonroboticsptyltd3665]

+Jacek Pawłowski I liked the music. I was on a sixties alien planet finding new life.

[@ChipGuy]

Guess why algorithm-generated music didn't really take off ;) It may be interesting on it's own but surely not suitable as background music for these kinda videos.

[@youpattube1]

Some people think a soundtrack must include drums. Sad.

[@youpattube1]

So as to not bother you with a question you have already answered, I read all the comments and responses before asking this. I found the combination of your measured narration and the soundtrack to be relaxing/mesmerizing. I understand that the sound is generated, but would you mind giving more info about it ? Not that I look for special treatment, but I am one of your patreons.

[@johncherry108]

At last, a KZbin video which DOESN'T begin with a greeting like "Yo, what's happening, man?" Those things really irritate me, and I usually close the video at that point.

[@suzannemccutcheon8741]

Well made easy to use

[@matti17690815]

Nice video. I have just used a Dremel for the DALLAS chip and soldered the new outside battery to the pins...

[@andymouse]

You've come a long way !....cheers.

[@bigbox8992]

the design is so beautiful and primal. that screen is a delight.

[@lambertax]

I would have put a good quality socket for sure... expect if the height...

[@rhythmhappenings3578]

How am I just now coming across old Marco reps. Forbidden content. Thanks also, this is my first scope :)

[@kirkpennock2997]

i like the sound. Compressed air from air comp works so nice to clean like new.

[@eugenfrick559]

I'm wondering why they didn't used a socket for the Dallas chip

[@jamesgrimwood1285]

The slightly unnerving soundtrack, combined with your calm, methodical accent made it sound like I was watching some sort of electronics torture film :) Those battery-backed chips are nasty things. Arcade cabinets used to have them containing decryption keys for the game ROMS.

[@nasralquds]

thank you ,I have the same model but with different error message .to clear, cycle power with one front-panel key pressed..., can you help please ?

[@Stampe-OZ0AS]

Did you solve the problem?

[@schneisim]

This... was very relaxing. Thank you.

[@stormchsr101]

wow. i have a 54600a . does the calibration on mine the same as the video?

[@rabeabenmaarouf5140]

Hi, thank you for the video and the explanation. What does it happen if I use ds1230y-150 instead of ds1230y-120?

[@reps]

+Rabea Ben Maarouf I believe that last number is the acess time in ns. But these oscopes don't rely on fast r/w of its calibration data, so using one with a higher access time shouldn't cause problems. (purely guessing here!) Though try to avoid old stock! 10 years from the date of manufacture.

[@rabeabenmaarouf5140]

+FPV Electronics Thank you very much for your response and explanations, have a good day!

[@OctavMandru]

Absolutely beautiful main board and construction in general. Good video about it, nobody builds like that anymore (I think, maybe NASA). Sountrack... maybe if it was a bit quiter... Great work as always, none the less.

[@packratswhatif.3990]

What other option is there for that battery memory chip ? Guess you could just add a separate lithium battery with an extra plug for a second battery change out.

[@Swataia]

Thanks for very nice informative video! This job is waiting me when I get a new Dallas chip. Luckily I have desoldering station so it will be easier job. Its been a good scope, only thing I don't like is quite noisy fan sound, which is normal for these early digiscopes tough. Unbelievable that there is all equipped in the unit for a calibration!

[@dinosworkshop6870]

Absolutely fantastic repair video!!!!!!!!!!!!! Great work. Thumbs up on a very good tutorial. Thanks so much !!!

[@Huderson]

Very good friend your video! I would need the motherboard wiring diagram do you have it?

[@electron-1979]

Am I now healed, like the HP?

[@PauloConstantino167]

Hello. I have one of these and It was perfect but I left it unused for a few months and it became uncalibrated. For example a +ve DC voltage source doesnt show correctly. The voltage shows as negative on the scope, and turning the voltage division knob makes it jump all over the shop. What do you think this could be? Should I just calibrate it? I did the standard cal but didnt solve it.

[@Fredjoe5]

Disregard the comments about the background music and instead get some ESD precautions, such as getting off that carpet, setting up an ESD station, and using a wrist strap.

[@Uvisir]

Marco, where can i hear just the music? Is it your bowl music?

[@MichaelKingsfordGray]

Why the grating background Sturm?

[@newlyrossetti4803]

Hi Marco, thank you very much for this detailed video tutorial.

[@douro20]

I wish my LeCroy 9410 was that easy to service. Granted, all the digitizing hardware and the CPU plug into a FastBus backplane, but the frontend and the video card are much harder to get to.

[@1959Berre]

The guy is German, technically highly qualified and specialized in mental torture. You do not want to live in his head... :) But I like his videos.

[@khroe]

This was helpful, I have the exact same scope that developed the exact same problem, performed the same fix with the same results, thank you.

[@sebastianschneider4252]

Are soundtrack is "Brian Eno" "music for the airports" ?

[@ChrisWilson5006]

Excellent video, I have just acquired one of these `scopes, may I ask exactly where you bought the new chip from please? Thanks for sharing the repair.

[@stryder751]

Question for a newbie, is it better to get a Siglent Technologies SDS1202X-E 200 mhz which is 2 channel and $20 more or the 4 channel 50 MHZ Rigol 1054?

[@reps]

Would you trust the judgement of someone who thought it was a good idea to add this soundtrack to his video at some point? :) I'd say Rigol! Because even as you transition to a non-newbie, you'll rarely exceed the bandwidth of the Rigol DS1054 (unless you specifically pursue HF stuff). It has all the hardware for higher bandwidth built-in already and when unlocked it's good to go even beyond the 100 MHz from the spec sheet. Up to around 150 MHz with very litte attenuation, over 200 MHz with significant attenuation (meaning the signal gets weaker)

[@chrisyln1]

hi do you know what the dc cal voltage is at the back BNC socket

[@ChipGuy]

12:15: No socket for the Dallas chip, eewwww! That music is irritating btw

[@joelw781]

Fun to watch....I worked for HP Colorado Springs in the late 1980s when this product was introduced.

[@0xbenedikt]

For the calibration, I would not use a single wire, as you did. While the grounds are connected, the signal is not shielded as you are aware of, so the calibration can be off.

[@vladimirriabov459]

Hi! I have the same model which starts to shut down soon after power up. Screen shows warning: cal ram unprotected. Is it likely to be caused by same problem(described here)? The unit was in storage for long time before it was given to me... Thank you!

[@reps]

+Vladimir Riabov There is a switch on the back of the unit that lets you turn RAM protection on. Dead NVRAM module usually produces a checksum error if I remember correctly.

[@JohnCena-iw2vk]

the background noise is making me slightly uncomfortable.

[@heiligcomp]

Can anyone please tell what the part number is for that chip?

[@kkendall99]

Whats the deal with all the irritating sound effects?

[@Kennynva]

I 100% AGREE

[@barroweer]

awfully sound

[@sendark001]

They are healing Tibetan bowls. You have now been healed of your anger issues.

[@Bigwingrider1800]

DOESN'T THE SCREEN HOLD A HIGH VOLTAGE CHARGE?

[@GeorgeTsiros]

THE SCREEN ITSELF, I DON'T THINK SO, BUT SOME OF THE COMPONENTS CONNECTED TO IT CERTAINLY DO.

[@ruhnet]

Oooooooh great and mystic Marco: can you heeeerrre me oh great one?? We your most humble viewers thank you that we no longer must suffer the agony of this music on your more recent videos. 😁🤣

[@ianshepherd917]

Very annoying and unnecessary soundtrack. Silence is golden!

[@reallyniceaudio]

Cool disconnect your speakers!

[@xConundrumx]

@@reallyniceaudio or even better click the speaker icon at the bottom of the video and mute sound. But of course you would also lose the commentary :)

[@thebood4553]

Great repair tips for this model. Thank you for sharing your knowledge!

[@dalmolima8862]

Very good, thank you. The sound in background it is very sinister , but if you are Dracula or HAL9000 computer it is very appropriated!

[@scottkirkpatrick8516]

He should have put in a socket and I'm surprised the IC wasn't socketed to begin with. Perhaps this was out of concern that the part could potentially come loose due to vibration. If that's the case, they could have put in a tie wrap or some other mechanism to keep it secure in the socket. I had to replace one such part in a Setra model 2000C part counting scale and it was socketed. The company that I work for even used a variation of the part with real-time clock and it was socketed.

[@williwuchtig3336]

Beautiful sounds.

[@drulli1]

Geiler Sound! Lief so oder so ähnlich in einer Ausstellung im Gasometer Oberhausen. Berge, glaube ich. Dort fand ich es sogar noch einen Tick transzendenter als mit der hp Büchse. 😁

[@dancahoon5349]

Liquid Solder Desolder - LSD music. Great Video. Great sense of humor!

[@siliquaesid703]

I have a 54502A same fault but this one won't even power up with this fault so I replaced the PCB battery with a rear panel mounted holder that way I don't have to strip down to change battery.

[@edgeeffect]

Is that Tibetan singing bowls in the sound track? Oh... seeing your answer to someone else's comment, it's digital. It works really well with the sounds of your camera struggling to focus too! ;)

[@EvertvanIngen]

German voice is very soothing... Is this ASMR? Is that a Canon EOS 500D you're using to film this? I recognize the autofocus mechanism sound :D

[@stryder751]

love the background music!!!

[@reps]

Oh you do? Well it was procedurally generated and I found that quite a charming idea. In another of my very early videos I tried a pure data program, that actually reacts to my voice. I wouldn't call the result groundbreaking, but I like the idea of "automatic audio decoration" without copyright n stuff

[@sanjursan]

Calibration starts at 20:00.

[@partisanguerrilla3167]

Sounds like Rife frequencies, great for focus!

[@chriskeegan2906]

great video. Not enough appreciation for HP scopes IMIHO. They're really so simple. Know of a forum where people can exchange info on these scopes?

[@a.bergantini4129]

I love the background music! I rewatch this video frequently before going to bed... it calms me down

[@lionheart8193]

Might as well use Ic socket next time...

[@dilpagalho4306]

No static protection while walking around on carpet? Why are you scratching up the nice table ? Should use a anti-static mat and wrist strap..clean off all the dust and electrical contacts with contact cleaner. Replace any electrolytics and film caps while you're at it. You half-assed it by not using a real BNC Cable. The ground return loop will be much longer if it has to go thru the chassis. Return current follows the signal at high speeds.

[@therealdjryan]

Beautiful soundtrack

[@youpattube1]

Perfect background soundtrack.

[@johnalexander2349]

Jesus! That "music" really grates my carrot!

[@artsandclouds]

soundtrack IS AMAZING!!! LOVED IT

[@Damjanhd]

when solder doesn't melt add your solder and than use pump

[@theelmonk]

Sound is fine (suit's Marco's pace perfectly). Soldered-in-memory is fine (sockets will be unreliable before the battery next runs out). It's that clip lead that gets me. Haven't you got a BNC lead ? :)

[@janosnagyj.9540]

All the EPROMs are in sockets, and a good, gold-plated precision one would definitely survive a lot of batteries... IMHO this is the only big mistake of this repair operation.

[@edhalferty]

I, for one, think the music is a good choice. I was going to suggest multiple audio tracks so people can choose voice-only, but apparently youtube doesn't support that. Amazing.

[@GeorgeTsiros]

replacing the crt with an lcd could easily bring down the size by half. It's mostly empty inside!

[@KuntalGhosh]

whats up with the ghostly sound track? lol

[@andrewverran6998]

I think it is a Theramin ,maybe he built it. Bought one of these for 100 bucks,only 2 years since it was calibrated,calibrated tagged 2/2017,next calibration due 2/2018 ..might post a viseo when i power it self diagnose test for the first time in a couple of days. . Great video for some like me who has ,in the 90s ,plenty of ACID.

[@wowacwejman2012]

good repair, nice ambient tune. :)

[@richardvickers148]

Thanks for the video ,You just helped me fix my HP 54501a NVram issue in my scope hahahaha ,Thank you

[@PiotrK2022]

@ Marco Reps Meh, IMO waste of time. That Dallas chips can be cealsy hacked by attach external battery holder and coin cell. Look: www.google.com/search?q=Dallas+rtc+chip+mod&oq=Dallas+rtc+chip+mod&aqs=chrome..69i57j33i160l3.8255j0j4&sourceid=chrome&ie=UTF-8

Its very weird that almost everyone has their first videos likes this and then they get comfortable doing videos..

[@scotshabalam2432]

Slenderman is coming from INSIDE THE CASE!!!

[@AlainHubert]

You've got a really slow and noisy auto-focus on that camera.

[@mattedj]

Yeah great ambient music

[@tookitogo]

Seriously, what's with the creepy yoga soundtrack? It adds nothing but distraction.

[@rubusroo68]

the dings are making me salivate

[@PlasmaHH]

Just mill away the case and replace the battery

[@scottferguson1932]

oh my god, the sounds... Make them stop, I beg you.