EEVblog 1564 - Agilent/Keysight U1273AX Multimeter Repair
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- เผยแพร่เมื่อ 27 พ.ค. 2024
- A very interesting repair of an Agilent/Keysight U1273AX OLED display multimeter. It had two distinct unrelated faults.
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00:00 - Faulty Agilent / Keysight U1273AX OLED display multimeter
01:36 - Battery leakage, OF COURSE!
04:26 - Bottom of PCB
05:47 - The OLED display
10:09 - Annoying voltage measurements
15:14 - At great expense to management, a new OLED
18:18 - Winner Winner Premature Dinner
20:19 - The Repair is over, right? RIGHT?
21:22 - Accuracy fault. Repair time again.
25:23 - Hybrid Thin Film Resistor Dividers
26:56 - Parallel contamination
29:44 - When in doubt, suck it off
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#ElectronicsCreators #Repair #Multimeter - วิทยาศาสตร์และเทคโนโลยี
OLED displays are extremely sensitive to oxygen and moisture ingress, which is one of the reasons they are expensive-- they must use a glass envelope with metal feedthroughs that is hermetically sealed. Can't recall the channel, but the owner actually did some of the R&D on the original displays, and he explained how that was a major hurdle when developing them, just how to create a perfect seal. Apparently it wasn't that difficult to get them emitting light, but without that seal they will very quickly fail.
Back in the day when OLED displays were quite a new thing, I had purchased a bunch of OLED character display modules to use in various projects. About a decade later, none of them work anymore, even ones that were still new in the box. The controller (HD44780 compatible) is alive and well but the OLED display emits no light at all. It would seem that when OLED was a very new technology, they hadn't quite figured out how to seal them properly.
Really cool but sounds like yet another reason to not use OLEDs in a meter. Just stick with good ol' LCD!
@HuygensOptics is the channel you are looking for, he has a video on how he did research on early OLED tech.
I wonder if this is the same reason cell phone OLEDs (the glass ones, not the film based ones that can be adhered to a rounded piece of glass for those stupid edges) completely stop showing an image once any part of it is broken.
I've had a few friends tell me they dropped their phone and it stopped turning on but in reality they managed to crack the oled without cracking the front glass and it simply stopped displaying an image.
but a lot of smartphones, generally high end ones use the soft oleds where the panel is kinda flexible, and even cutting a piece from it rest of the display is fine except for a few dead rows due to the cut, my point being there is technically no hermetic seal in those right?
Your recent repair videos demonstrate a remarkable ability for planning years ahead, leaving batteries in so many devices and waiting for them to leak. Of course, I find these videos quite entertaining, although my first thought is oh, Dave, not again.
It was really cool how you found the calibration fault by reasoning and analyzing the way the front end would work!💪
It's situations like this that have me fondly remembering our old-school ozone-killing Freon dip baths for PCB cleaning and decontamination.
Fail for Agilent.
Not only having their top tier multimeters failing their displays, but also not having spare screens available, luckily the aftermarket came to the rescue, this time.
@lakinnenlako6883 I can't vouch for their old instruments for electronics, but Agilent is a top tier chemistry instrumentation company. It's the world leader in high performance liquid chromatography.
@@lakinnenlako6883 Hardly, they are the defacto standard for an awful lot of test equipment.
@@EduardoWalcacerthey rebranded a few years back. Agilent is only medical now, Keysight is the test equipment company.
It seems to me that this meter was outsourced, no excuse still for its poor build quality. And the cost of these things is exorbitant compared to Fluke, FLIR, etc. for same specs.
@@lakinnenlako6883 this is indeed a video about the multimeter, not liquid chromatography or whatever that is 😁
I have this series of Agilent DVM, and leaking batteries absolutely wreak havoc on the plastic. I had to make do with popsicle sticks and epoxy as the “new” battery compartment since the old one turned to dust.
Interesting. There seem to be lots of subtle differences instrument plastics manufacture.
High impedance board cleaning would make a great topic for a video. Almost nothing about it on youtube. The proof of a clean board is a test at 90-95% humidity, cleanish boards can pass at low humidity like in an airconditioned room.
I was just thinking this. It would need a controlled experiment with high impedance exposed traces and controlled amounts of contaminent.
@@EEVblog that sounds great!
The humidity vs creepage path problem makes a good argument for conformal coating PCBs where accuracy is important.
Yeah man do it
Back to front is a very common issue. In the display controller it is done with a single bit, and if you are trying to send commands before display is ready, it may be missing that command. And those displays take forever to initialize.
I wonder how easy/difficult it would be to either increase the reset delay, or have the display hold the main meter in reset until it finishes doing its weird and wonderful things.
@@iamdarkyoshi Meter just sends the data, so display module MCU can just accept and wait it until the panel is ready. It would be an easy fix if the source code was available. OLED initialization just needs to be made more robust.
I assume STM32 here emulates the commands of the original display controller, so it is possible that it is actually just missing that register write for some reason.
It is 100% fixable, but it would be on the makers of the board to fix it.
Although logically, it makes no sense to even interpret the initialization commands for the original display. You just need to accept the data. So, the issue is purely in the initialization code in the new module.
@@AlexTaradovCan you dump the programming of an STM32 and put it through Ghidra?
@@der.SchtefanNot unless they forgot to lock it. And clonners are usually good with locking stuff up, they know how easy it is to clone things. In practice it would be much easier to re-implement the whole thing from scratch. It is not doing anything complicated or involved.
Contacting the vendor may also work. This does not look like a typical cheap garbage, there is a chance they want to know about the issue and can fix it on their own.
I recall sending my meter in for a recall. Keysight exchanged it for another model. I can't remember what the issue was with the original product though. Stinks because the OLED is great for use in pitch black electrical cabinets. Easy to read at any angle.
Downside is she chews the batteries compared to an LCD!
@@TradieTrev true.
To wash the pollution, it is not enough just spray and wipe with a brush, you need to collect the dissolved pollution using a napkin. If an alkali hit the printed circuit board, you must first wash it with a light solution of citric acid, then rinse with water with a soap, and then rinse with ethyl or isopropyl alcohol and wipe dry with a napkin. I saved a lot of electronics flooded with different active liquids (alkalis, acids, salt).
After neutralizing the alkaline stuff the best is to soak in lots of warm de-ionized water. Product of acid and base mixing is some kind of salt which in solution is conductive too
You'll find that your calibration problem is probably due to battery electrolyte soaked into the fibreglass of the pcb causing stray conduction paths. I have come across this problem before. It's a very difficult job trying to remove the paths by soaking it in solvents etc for many days, but always worth a try I suppose.
That could be tough to clean without destroying the PCB and you don't want to damage the surface mounted components. I find modern electronics almost impossible to fix.
That sounds prone to becoming sensitive to humidity, where the soaked in battery goo comes active on sticky days.
My lab received 5 of these as "freebies" when we bought real Agilent Source Measurement Units (~$10K each). Five years later NONE of them worked. No battery leakage. We threw them out. My Fluke 23 I bought new in 1981 works like the day I bought it. All the handhelds we use now in the lab are brand 'F'.
Dave!!! I have a similar model Keysite that had leaking batteries and has never been the same since. I cleaned it but now will give it another shot based on your repair! So glad i watched to the end. Thanks for such high quality videos!
By chance I ran into someone I didn't know and we both agreed that this was 1st class infotainment. Just saying. Cheers!
Amazing repair. Great diagnostic and reasoning to isolate the problem and $80 for a screen is still worth it for this high end meter. The screen is beautiful.
Nice, Thanks for all your work, video and all.
. Great repair video. Finally. Thank you, Dave
Nice repair !
My OLED went on my U1273AX - just completely blank one day. I ordered an LC-OL12864-09-YO-A7 from LC Design (Germany, around 110 euro incl shipping) and it dropped straight in & works perfectly. Such a shame Agilent presumably know full well this is a design issue on a very pricey meter (as they offered replacement screen modules) - Didyou see their pricing for a replacement (when they offered it)? Truly stupid expensive. It's my most expensive meter, and the one that lasted the least long. Now happily working again without fault. Nice video, Dave, as always.
brilliant video dave always love how you faultfind thanks for shareing.
Great repair!
Great job loved the repair job fantastic love your channel
Winner winner, chicken dinner! That's one more back in the world of the living. I love your ACV standard :)
That standard is pretty schmick.
@@EEVblog a thing of beauty indeed! I love the Cold War era electronics. Especially if it comes in a 19" rackmount form factor, haha!
@@KeritechElectronics Does take up a lot of room though.
Nice repair!
informational!
Some suit made a genious move with pushing for oled, it makes people wanting new stuff want it and it breaks far faster so companies will outright replace the device instead of repair if it fails after warranty.
They looked at meters working just fine 10-20 years after production and went "THAT IS NOT ACCEPTABLE"
Always wondered how Fluke stays in business as it's buy one last forever model isn't good for repeat business.
@@jonfreeman9682 By having reputation and people thinking that buying Fluke makes them real engineers
I bought the 1253A, and that OLED is N/A. I then bought a newer meter refurbished from Agilent and it’s display was going out. Grrr. I bought an aftermarket display and I’m back in business. Those OLEDs last 10 years max, no matter the power-on hours.
Nice repair thank you!
Ah the good ol SSD1303 display issue. They only make ssd1305 now which fits but then the picture is flipped, hence needing a whole new driver board.
Nivona 855 coffee machines have this same issue.
Exelent video, Mr Jones,.🎩
“Reverse engineering” - Literally 🤣
Interesting. I recently changed the exact same screen on an aftermarket car product (apexi power fc hand commander). Took a punt on the aliexpress one (£60 delivered) and it worked. My first time soldering fpc too
I'm glad the budget only stretched to a lesser model with an LCD when I bought my Agilent (U1232A) meter
I bought my el-cheapo DMM about 20 years ago, and it still works. 🙂
But can you reverse the display on it so you can view it with a mirror.
Well el cheapo accuracy is likely off as they don't test or calibrate these things. They're produced to be disposable. But hey they work.
@@ianhaylock7409 I can think of a few times when that would have come in very handy. 🙂
@@jonfreeman9682 I've never needed that much accuracy, nice but not needed. 🙂
I would use the choice of OLED over LCD in an otherwise equivalent Keysight DMM as a really good tell in a job interview.
Another Save by Dave 😁
The OLEDs on TS100 Irons go bad for no other reason than they want to !...cheers.
Had that happen on my exmaple
But that's a product in a totally different priceclass.
A ts100 display can be had delivered for $4 or so and the complete iron is like $60.
This multimeter is supposed to be a top tier product, priced at $500 or 600 or so.
yes it shows High end kit and Low end kit have the same problem with OLED@@mrpetit2
Well what do you know! I acquired a 1273A which had the exact same issue - suffered battery leakage and was scrapped due to being out of calibration. Pulled that same capacitor and gave it a good cleaning (despite no signs of gunk under it) and it seems to have fixed it. This'll be a nice upgrade over the AN8008 previously bought due to Dave's video on cheap meters 🤣
It still has the RF interference problem on the current range but I can live with that...
The reverse image is a feature not a bug 😅
I have a Fluke with battery damage, after cleaning, restauration of the contacts, 3 years ago, it failed this week. Feeding it with a bench supply there was no problem. When I wanted to clean the again corroded battery contacts, one of the still good looking contact dropped off in 2 parts. Turned out to be corroded away from the backside. For battery leakage repairs I always remove parts and clean under them, did that here too, but not the battery contacts. Also had something similar on an other meter, there the wire from battery holder to PCB was corroded away from the inside of the wire.
Battery damage if not too bad you can still clean and repair as long as the surface mount components haven't eroded. I haven't come across too many battery leaks. Not sure what causes it but for extended non use it's best to leave the batteries out.
Looks like a really hard bend on the OLED flex. Wouldn't be surprised.
Great troubleshooting David. I had a feeling the battery leakage was under a component. Still NO easy finding that one !
You and Paul Carlson do a super explanation of electronics fault finding, and repair.
Sad to see how much dollar pinching is going on new electronic test equipment.
I remember many Years ago using Hewlett Packard Optical Spectrum Analyzer HP OSA 70004A / 70952B, I used just to align the input collimator to the first wave splitter filters, was great equipment to use FUN TOO yet made The Brain go on Full Afterburner.
If you have done any work on optical test gear David, could you reply with a playlist please. Thanks
Best
Kristy
This is my favourite multimeter. The OLED screen is great to read at any angle. Also I use the non-OLED version of this which I don't like as much. Also I find that the Fluke 289 is the worst LCD I've ever used (can't read it unless looking at it directly).
On the U1273AX, I've disabled that silly startup melody and also disabled auto power off (nothing worse than using all hands and legs to probe something with the tongue at the right angle and the DMM beeps and goes off!).
OLED is the future of high end meters. They need to differentiate with cheap meters. OLED definitely looks more cool even if it's kinda gimmicky. Would be nice if they use higher res OLED and add more useful functionality.
This is why I ALWAYS using Energizer lithium's because they are lighter, have more power, voltage hardly drops AND they don't leak.
Great repair! The meter is up to AUD$359 already with 3.5 days to go. I probably won't get it but I have a strange urge to buy a Lenovo headset.
And now the listing has been pulled, item is 'lost or broken'. I wonder what happened.
Awesome!
I avoid OLED now if I can help it, I have a 1" one on my DIY solar/house power monitor its on 24/7 and it gets weaker and weaker with every month.
LOL at Dave's sound effects rendition
It's a shame such a nice, premium meter has a major reliability issue with the screen. Perhaps a few more will be repaired thanks to your video.
It is only marketed as nice and premium, it is trash. OLED is not the right thing to use for frequently used electronics (eyes strain) and it is not reliable as rugged indicator either.
Just another reminder why Fluke meters are worth their cost
Dave, doing Robert De Niro Facial expression😄
Did the exact same OLED module replacement you did, but the module I bought has a bug where when it shows the negative sign, one or two columns of pixels of that minus sign are basically wrapped around to the right side. A bit distracting I have to say. Messaged the seller and they actually came back with a detailed explanation of the issue, but I'm not convinced they couldn't have done something to suppress it. It doesn't have the reset issue yours has though lol
So did they have a solution. Is it defective or faulty design. That's the problem with 3rd party parts.
My U1253B had a long history of failures and finally gave up the ghost with the OLED, worst purchase decision I've ever made when it comes to test equipment.
Fluke is the best meter on the planet. Have been using fluke from the 1980s. All others fail
@@clivewright7778 Yeah, I was thinking of getting one but my use case heavily depends on very fast refresh rate of the display, and I didn't really see Fluke meters offer that so far unfortunately, If I found one I would get it immediately.
Reason the screen ( New one was back to Front ) Dave was because it was reverse Engineered lol
Now I really want to sample you making the startup sound (at ~ 3:52) and mod my multimeter to play your version.
I love my Brymen BM786 😄
What I learned is, recycle your plastics with batteries and they take care of each other 😂
i think the plastic cracked because the metal screw increased in volume when corroding
Nice
I saw on Mr Carlson's Lab one of these displays faded a lot. Seems to be a very common failure.
Battery manufacturers need to be accountable for battery damaged devices
Duracell will pay for a replacement item damaged by battery leakage, I've been paid out for 2 D cell Maglights ruined by leaking Duracell batteries.
I am blown away. Dave actually repaired something! Whats the current status of your "clock" project with this weird case from a gas detector thingy?
Dave has repaired other things too. He's got some great videos showing how he diagnose and fix defective equipment. The challenge is always getting parts.
Note to Agilent. Keep sensitive areas of meter away from venting batteries….
Hi What the value the capacitor that you unsolder ( the white color capacitor) thanks.
Isn't the startup sound a check for the speakers all frequencies? As a self-test.
But imagine that you need to look at your multimeter from a mirror!Niiiice! 🤣
Thanks Dave for this vid... I stupidly invested in the U1453A DMM but also the U1253B 'blue' coloured OLED insulation meter. It was not a cheap kit either & in 4yrs probably used it 4 times.... until the other day i really needed it & find it's gone dark on the OLED & Keysight have ensured i will never support them again! So finding another OLED for it is going to be interesting & since my daily use U1453A with its yellow OLED is still rolling along fine i guess i'll be up for spending time to have my U1253B usable again....
Mine has the same problem in one of the ranges.
Isn't that just a 0.05" pin header? Buy or make a ribbon cable for it to be able to probe the control board. Also, 138mA current draw is with all pixels on, which is atypical. With only 10% of pixels on you're looking at more like 14mA.
Dave. I only own Fluke meters, because... They were the meters that you dropped from a hill onto concrete, and you even took them swimming with you! Lol
Nice little $700 multimeter.
Do you know how to calibrate extech clamp meter .I turned potentiometer and I think I need jumper wire to processor .It changes with the weather now with about 300 mv
👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏👏 Great, Dave!
On the battery corrosion issue, I'm sure I'm the only one in the world who has replaced all the alkaline batteries in my devices with Lithium Ion. Undoubtedly a grocery list of reasons NOT to do this, but after have the batteries corrode in my EEVBLOG meter--I made the switch. And no more corrosion issues--just fire issues (LOL).
I’ve done this too with items of significant value. For the cheap items I didn’t bother.
@@timwhite8500 I bought a wholr bunch of AA & AAA Lithium batts so did everything. Even my toys.
Lithium batteries are not cheap. But they definitely last a long time. You buy a set they last forever.
@@jonfreeman9682 The most important thing to me is not have corrosion which will leak and destroy my devices. I have many gadgets which aren't use for months or years. Lithium batts puts a stop to this.
@@shubus Lithium batteries can leak too but they're less prone to leak than alkaline. You can also use carbon zinc. They're the cheapest and I heard they don't leak but not sure.
Dodgy OLED display panels are starting to worry me a bit - I bought an ASUS Vivobook with an OLED display last year. So far the thing is beautiful, but now I'm wondering just how much long it'll be before I have to replace that hi-tech panel... :(
I avoid using alkaline batteries in anything that doesn't see frequent use. I'm gradually switching to lithium ion, but I'm still happy with carbon cells, for the safety of my devices.
So you're saying only alkaline leak. Carbon and lithium can leak too. We use alkaline as it lasts longer.
@@jonfreeman9682 Indeed, I bought a brand new 996 battery (the big square 6V one) and it was dead; I couldn't be bothered returning it, so I popped the top off and found 2 of the 4 cells were heavily corroded with almost no zinc left. This was a Varta battery, although I note it was made in China and had no production date marked on it.
@@cambridgemart2075 Thanks for sharing. I use alkaline as it's cheaper than lithium which lasts longer but lithium is expensive. Carbon is cheapest but for double the price you get better quality with alkaline which holds the charge longer. I think all batteries can leak and the cause is moisture humidity and overheating of the batteries which cause swelling so the seals are broken and moisture gets in reacting with the chemicals hence corrosion and leak. But lithium is definitely higher build quality. I think if you keep equipment in a dry cool place there won't be any leak no matter carbon or alkaline.
Pretty sure I've seen a clothes washer (or dish washer) with the exact same startup sound
Life is too short to buy Agilent/Keysight meters.
IS THEIR SOME TYPE OF PADD WE CAN PUT UNDER A BATTERY TO STOP CORROSION OF A UNIT FROM BATTERY LEAKAGE?
For how good and nice to use OLED screens are for multimeters, they are kind of a mixed bag in terms of longevity. Especially when you are dropping something like 700USD on a bench multimeter that is similar to this (the keysight 34450A).
When the display died about a year after I bought mine it costed more to ship it to keysight to repair it under warranty than to just buy a replacement screen and do it yourself. Changed the color to a more high contrast yellow too in the process.
OLED are great and last a long time. Practically as long as LCD and look much nicer. But expensive to replace.
@@jonfreeman9682 That's not true. They don't last nearly as long as LCDs as the pixels get dimmer over time ("burn-in"). While they are more expensive, the difference is not massive. The only reason it is expensive to replace in this case is that it is custom to this model. A custom LCD would be pricy to replace too.
@@0xbenedikt I remember my old Samsung S4 phone did have OLED burn in but phones are on all the time. OLED should have improved since then. They are brighter and richer color than LCD so all top phones use them now. Meters should be able to use OLED without burn in as they're not on all the time. That being said meters don't really need such colorful displays like phones which are used for entertainment.
That sound and then a Markita charger there can play charge then the boss know there are been working.
Sorry, noob here.. So a bit of dirt under a component, like in this case, can throw the calibration of the meter off? What does it do? Is it increasing the capacitance or something because you deal with such tiny amounts of capacitance?
Would like to know, thanks!!🤔
Is the EEVblog forum working ? Or it is just a problem on my side? I get a database error.
0:57 Its fun. Some people like fun.
Auction ended: "lost or broken."
What's wrong with testing wether the beeper works on startup?
What batteries do you recommend that dont corrode?
Anything without Alkaline
Re the OLED orientation: They call it "reverse engineering" for a reason, don't they? 🤣🤣🤣
Wait... that sound is what it is supposed to do?
When's the next multimeter kayaking trip??
They are fun but I've never been successful repairing and simply toss it out.
All the 6 OLED models failed me after the warranty passed.
Taobao has the whole module for 22.00 USD (160.00 RMB)
I really don't like the the 1272A ... quite a few measurements are incredibly slow, you sometimes have to wait several long seconds to get near to the proper measurement. Also often the resistor measurements drifts away happily for minutes.
OLEDs are a terrible idea for a handheld battery powered device that's supposed to be reliable on the field and keep working under tough conditions for a long time. I don't know who thought this would be a great idea.
OLED display prices have come down so you see them more often in equipment now. High end premium meters use them as it looks nicer. A definite step up from dinosaur LCD tech.
I wonder how many oled panels will be working in 10 years time?
They can last 10+ or more years no problem. Depends on usage.
Silicon chip and electronics australia still around in australia? ;))
Ultrasonic shower?
Hi Dave, You still didn't respond to my request. Did you find a spare LCD panel for my BM235?
If it didn't make a doobly-doop 1980's bleep bloop start up sound, how would you know that it was the screen??
What do you do about batteries? I guess take them out of devices if not using regularly. I've had too many leak in test equipment in the past.
Eneloops.
My usual problem is that I am using the device regularly, but then something comes along and the device sits unused for an unpredictable amount of time. Sort of a side effect of having too much stuff and too many interesting projects partially completed.
Are there any leak proof batteries that you can safely leave in any equipment? @@mikebarushok5361
Generally batteries don't leak. Put devices in a cool dry place and it'll be fine. I think it's heat that causes battery to leak.
I used to fix TV's in front of a mirror so I could see the screen while probing the chassis in back. A meter that reads right seen n a mirror could be handy! (OK no, not really ;^)
You liked silicon chip and electronics australia magazines? you work now on microscopy? different tech mate!