Agilent Keysight 3034a X-Series Oscilloscope Repair
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- เผยแพร่เมื่อ 27 ส.ค. 2024
- Let me know what you think!
www.salvagedci...
Time Guide:
00:30 inspecting oscilloscope
02:22 inside the oscilloscope
03:53 quick look at the internal power supply
05:47 first guesstimate of failure
10:07 check if oscilloscope works without PSU
10:57 Update procedure for 3034a Oscilloscope
12:26 out of circuit component analysis
16:35 Repair attempt 2
18:00 deeper failure analysis
21:47 Resoldering process
21:50 easteregg
25:30 PSU fix first test
26:00 reassembly
26:55 testing the fully assembled oscilloscope
Repair Details:
Datasheet for look-a-like lineage branded CCH125 power supply:
www.eevblog.co...
Genuine Keysight PSU repair part: 0950-5277
www.keysight.c...
Relevant EEVblog forum thread:
www.eevblog.co...
Power Supply Replacement Candidates:
www.digikey.co...
www.digikey.co...
Will need ps_on inverted:
www.digikey.co...
www.digikey.co...
Keysight InfiniiVision 3000 X-Series Oscilloscope Firmware (latest)
www.keysight.c...
PARTS PURCHASED:
Original mosfet:
www.digikey.co...
Replacement mosfet:
www.digikey.co...
Two pin Diode package near mosfet:
www.digikey.co...
Current mode controller:
www.digikey.co...
Replacement MOV:
www.arrow.com/...
Replacement NTC Varistor:
www.arrow.com/...
Replacement Fuse:
www.digikey.co...
Replacement 1w 22k resistor under main filter capacitor:
www.arrow.com/...
Tall cap I selected:
www.digikey.co...
Dimensionally compatible cap:
www.digikey.co...
At 23:41, if you use the hotglue method, make sure to use high-temp hotglue.
Alternatively, instead of using hot glue or a spacer, it is probably easier and more effective to just replace the (4) 1w 22k SMT resistors under the main cap with a 2w 88k THT resistor and space it from off the pcb slightly then add electrical tape to the back side of the oscilloscope aluminum frame to prevent the resistor from coming in contact with it. Close valued part:
www.digikey.com/product-detail/en/te-connectivity-passive-product/RR02J91KTB/A138369CT-ND/9371770
Song Lyrics:
Elton john - Someone saved my life tonight (Soldering iron party remix)
some-one saved my life tonight... soldering iron! (soldering iron!)
You almost had your hooks in me, oh didn't you you dear?
You nearly wrote me off and signed.
All about, compromise sweet signals, ringing in my ear
You're an LTI
And when a signal goes from low to high, rise away!
Rise away! Hi Hi
Michael McDonald - Real love (re-cal after-dark edition)
Darlin' I know, I'm just another tech at your bench...
If only just tonight, girl
let me hear no whine from your coils
Tell me that im the only man
that you ever really loved
Honey take me, back in eeprom memory, place where bits are all shifted right.
So very right (so very right)
Here, Darlin', stands another bench mate wantin' you
In and out your life, they come and they go
Your days and nights like a wheel that turns
Grindin' down a secret part of you
Deep inside your shell
Where nobody goes now, baby
When you say calibrate me
To anyone who approaches
Off a few hertz
goodbye my front end
but we've both lived long enough to know
that we'd trade it all right now
For just one minute of re-cal
re-cal now
re-cal
I need to believe that it's
re-cal
recal baby
re-cal
Whyyyy darling
re-cal
Oh, Just one minute of
re-cal
This is the single most useful TH-cam video I have ever watched. My MSO 2024A scope just let out a pop and turned off, and I thought I would need to send it in to be repaired and not have it for a month. Not only did this video identify the cause of my scope dying but after watching him run his scope off of his bench power supply - I realized I can do the same with mine and get back to work today. Great job man.
Glad the video came in use!
@@SalvagedCircuitry we had the exact same failure - thank you so much!
@@RandomUser2401 Glad it helped!
@@SalvagedCircuitry :+1: Do you know how the original PSU is controlled? Is there a standby supply to control the "remote" pin? Also, is the Fan really powered from the PSU power-good (PG)?
I was impressed by the performance. For this reason, I subscribed wanting to have more!
I knew that when I found this channel that some day I'd be watching cool teardown/repair videos.
Was worth the wait.
Hahaha. Thanks!
After the music, I had to sub. Lol
Nice vid btw.
Cheers!!
Cheers mate. You saved us from a 3k repair
I've worked a lot on the 4000A and could feed 13V directly to the main board connector. Didn't realize, until this video, that the small board creates the other supplies for 3000x series (3000A and 3000T). Thanks.
Interesting video! Didn't know there were 3x5 standard PSU boards, really helpful to know.
I think that maybe your failure analysis is wrong though? You talked as though the electrolytic had AC across it (which it can't support) and the "diode protection" before it that you talked about looked like the primary side rectifier. I'm sure you know more, but my guess at the failure mode is that the MOSFET is the switching transistor for the primary side of the transformer. It shorted (putting out a high voltage on the base thus killing the control chip), this short caused the resistors in series with the large electrolytic (maybe as a primary current sense?) to heat causing the electrolytic to vent. At some point the fuse eventually went preventing a fire.
BTW you're the first singing repairman I've seen, will keep watching :-)
Keep uploading brother I learn a lot from this video
My MSO3104 fan out because of exactly that reason. Thank you for the helpful guide. On my power supply, R7 (0.11 Ohms 5%) is gone also.
This was really helpful. I had my Agilent/Keysight power supply quit 2 days ago and you really saved me some work. Thank you. I'm looking for the power supply comparison, but I can't find it.
Thank you for the video
Singing is 10/10
Would probe that
That keyboard solo, 10/10 : ]
:D
i think the background music is the best 😜
Very good and thorough coverage, electronically sound descriptions. one added thing stick with electronics, not sure the singing career is going to take off :)>. One other note the power supply is rated for 2A max hence 2.? current draw will also cause overheating of the PS.
Very informative, thanks! I have a 3034A at work with a power supply that failed in an identical manner, but also the unit doesn't properly power on with 12V from a bench power supply. Any suggestions for next troubleshooting steps?
Grab a Meanwell EPP-300-12 or an RPS-300-12 and follow my most recent guide on the flash nand recovery:
salvagedcircuitry.com/2000a-nand-recovery.html
Or, send your scope into keysight, they will charge you for a new power supply and labor and might still cover the failed nand for free. The last time I heard, the power supply replacement is $300-400 USD. You do get a free calibration with the nand repair, which is great.
One detail .The Mosfets and diodes are on a common heatsink and the disassembly show that there is a common mounting point to the case of mosfet with no screws on center tab.I think this was on purpose as potentials are different. I see that screws were added in reassembly .I hope insulators were used.
Good eye. The shared heatsink is covered in kapton tape from factory and the screws are fixtured to metal strips that clamp the plastic dipped part of the to-220 package.
thanks for the video. Could you suggest me where I can get a schematic for agilent 54855A DSO 6GHZ scope.
I accidentally shorted power connector (ATX style) then somehow it is not turning on. Seems like the power supply is OK,
it is outputting all the voltages (there is a separate analog voltage generation board and when I disconnect from it and connect the power plug)
I can measure all voltages within range on SPS.
The front panel buttons are not working, but it power on itself and can boot without that connector plugged in.
Lineage Power))) ! Lineage 2 Chronicle One)
Can anyone tell me what the resistance of the resistor at the upper right pin(as seen in the image at 22:12) is? The pin is INPUT2 of the LP339M. It got fried in my Power Supply and I struggle to find the correct value.
You are a hero! Our DSO-X3014A from 2014 popped a fuse in our main line the other day and Keysight repair was quoted at 3.100 USD!! I took apart the instrument and sure enough, the PSU had a black spot under it. The Mosfet seemed OK but when disassembling I noticed a small black flake falling out. When examined under the microscope the marking clearly read 3042 :). I think we have the culprit. Changed the cap to be sxtra sure using your thermal insulation method. Scope worked fine on bench supply after beefing up the transient current supply capability with extra capacitors on the 12V.
Does anyone know if the 6.0V output is actually needed for the scope?
HI! I was glad that I can help. Here is the datasheet to the exact PSU agilent used. it is a CCH125 series 3x5 12v psu:
www.stockcheck.com/uploads/cherokee-international-cch125series-125-watt-switching-power-supply-datasheet1-162713.pdf
I would highly suggest to not repair the included PSU. Frankly, it is not worth the time or money. The overall power supply is just poorly designed. My repaired psu passed several hours of load testing at 30%, 50% and 90% under an electronic load, so I am confident my repairs worked, but I took thermal images of the unit under load and compared them to the meanwell
RPSG-160-12. The meanwell is roughly 15c cooler in operation. I would highly suggest grabbing the RPSG-160-12 from mouser instead and just making a new wiring harness:
www.mouser.com/ProductDetail/MEAN-WELL/RPSG-160-12?qs=StI9JdmCm6vmY5FsftfMUA%3D%3D
i have a Hantek DSO2D10 and i think i put 3000 volts on channel 2 so its not working anymore channel 1 is working what do you think i should look for to repair that channel 2 ? there is a signal on it but not messuring the right values
Kinda looks like the PFC(power factor correction) circuit may have freaked out.
The PFC circuit is basically a boost converter, that converts mains filtered by a tiny capacitor to a higher voltage on the big "mains" eletrolytic capacitor.
The big ring-core inductor, the foil capacitor, big eletrolytic capacitor, and diode+FET kinda hints to the function of the circuit.
Good point! Thanks for pointing this out. I was focusing on the circuit protection elements but didn't realize the traditional PFC layout. Thanks!
@@SalvagedCircuitry I would suggest retesting that circuit, it's probably still broken.
Whatever that drive that mosfet probably didn't like mains.
@@erlendse Yeah, the current mode controller which was responsible for driving the main switching mosfet was toast. I replaced it with an updated part. I checked all connected nearby components and they all checked out. The link to the part is in the video description.
@@SalvagedCircuitry Yes, you replaced the UC3842 (current mode flyback controller).
But that controller is not a PFC controller, you have multi-sage supply there.
The PFC controller meassure input voltage from rectifier, and bus capacitor voltage (via the resistors), and via a voltage multiplier varies the input current to follow the input voltage.
You should ideally check the capacitor voltage, to know the PFC section works.
I would expect something in the 350V - 400V range (even if mains happends to be 110V).
You will get 12V out with a faulty PFC section, possibly with somewhat limited current handling.
I don't quite remember how it works, but there's a way to add more licenses to these oscilloscopes - a friend of mine did it at our university lab. Possibly you need to leave an USB stick in there to activate the licenses on every power up, but it's definitely possible. Might be worth looking into
The singing is on point by the way 10/10
@@DerinTheErkan hahaha. Thanks. Yeah I believe there's an eevblog forum post about it. I'm just glad the scope is back up and running. If the oscilloscope had a boot-flash problem it would have been a lot more messy of a fix than a power problem.
I think i hav same issue with mine..which 2 pins you have connected with your bench power supply to check if rest of scope is good?
I watched it!
Awesome :D
The resistor immediately under Q1 is also smoked on mine, and I cannot read or measure the correct value. I noticed you soldered a thru-hole version to the underside, but can't make out the colors. It looks like Green-Blue-Black-(Grey?)-(Purple?) which doesn't make much sense. My entire Q1 was shorted across all terminals which would mean mains voltage was fed into the current controller IC as well, likely through this resistor. My trace didn't have any arcing to it, but it probably didn't need it since the gate on Q1 was shorted to source and drain. I checked the data sheet for the current controller and it only spec'd a low value of resistor in one use case, which seemed different from this application. I suppose it doesn't matter all that much, but with the gate capacitance and the switching frequency (500KHz), it can't be too large or it wouldn't work. Any suggestions?
For those interested, I found in a TI Datasheet for the (supposedly pin-compatible equivalent) that this elusive resistor should be between 10 and 20 ohms. www.ti.com/lit/an/slua143/slua143.pdf?ts=1663034205346&ref_url=https%253A%252F%252Fwww.google.com%252F see page 3-61 Figure 18.
I confirmed the value of the blown SMT resistor as a 5R11. That's 5.11 ohms, in what looks like an 0804 package.
What's the value of the resistor you replaced ? Can't quite read it on the video and mine is blown too (and marking unreadable ...). The one next to it as well (blue one).
I'd like to know this too. Can't quite make out the color bands with his thru-hole substitute. My scope blew this morning and I'm lucky I found this video. I ordered replacement parts and apparently just got the last UC3842B's on the planet until 2023Q2. You can still get the 0-70C versions but with the way it blew, I think I need to go all the way to 104 to be safe.
I feel like with all these scopes blowing up violently there is something Agilent should be doing about it.
Thanks for the video... on another note: I don't know any tech's that are not musicians... lol
hello friend.
I have this same equipment and with a defect identical to this one. So thank you infinitely for this video. Could you help me with a doubt? Could you tell me if the 12 volt power input without PSU is exactly at 10:07 in the video, are they on pin 2 with positive and 5 with negative of the connector? In the video I could not have a clear view of this. I'm sorry if asking seems a little silly.
You will find what you seek in the original CCH125 PSU datasheet here:
library.industrialsolutions.abb.com/publibrary/checkout/CCH125?TNR=Data%20Sheets%7CCCH125%7CPDF
Also read up on this forum thread:
www.eevblog.com/forum/repair/dso-x-3024a-power-supply-defect/
@@SalvagedCircuitry Thank you very much master.
Nice
How did he reattach the solder pads that lifted at 22:22? I suspect he just repositioned the pads and reflowed the solder with flux? If he used some kind of adhesive, what type/brand? Thanks for any advice!
Edit: Hilarious singing montage along with great electrical expertise. Made me laugh.
I added gorilla superglue gel below each pad with a needle. I put a tiny dab of superglue on the tip of the needle, enough that it makes a small drop, and then applied it under the pulled up pad. I then held the pad in place for a little more than a minute (the video segment was sped up and shortened). This method seems to work decently well, but there may be a better cyanoacrylate glue for the job. I usually use gorilla superglue / loctite superglue because they are very readily available. I'm glad you like the video :D
22:00 NOOOOOO!!!! PLEASE GOD! NOOOOOOO!!!!!!!
(nice singing though :-))
Hi Friend, its me again. My PSU did not repair.
It literally doesn't show the 12 volts. I believe it is definitely irreparable. And I find it difficult to buy quality components in Brazil and the shipping time for good components here is too long. I followed your conversations on the forum and at some point you say that a MeanWell RPSG-160-12 is the best option to replace it, right? Could you tell me if with this replacement source it would be plug and play, or would an adaptation be necessary?
There is no 100% direct replacement other than asking keysight / agilent themselves. They may still be able to sell you a replacement psu. The closest next alternative is the Mean Well RPS-300-12 or Mean Well EPP-300-12. Those psus are overkill, but they both have the remote sense wired identically to the oscilloscope and not inverted. You will need to create a custom wiring harness and slightly widen the mean well mounting holes. The mean well psus do not follow an exact 3x5 footprint, but they are incredibly close. Good luck.
@@SalvagedCircuitry hello . is that in my case, my equipment is not the 3034a, but a 2012a. That's why I asked if MeanWell RPSG-160-12 would be enough for this equipment. I don't intend to buy this original source, because I already realized that there is a manufacturing error, which probably in some time would burn again. Can you tell me if it would be possible to adapt a source without remote sense with enough power to supply this equipment. So, i have a good source 12v of 12A, 145w, but it doesn't have remove sense.
are you sure it's a good idea to put all that hot glue exactly above a bunch of hot resistors? Looks like a recipe for a mess...
Thanks for pointing this out. I did end up using high-temp hotglue. I forgot to mention this in the video. I originally had a 3d printed spacer planned, but I decided that having less surface contact would be a better idea.
Thinking back on this now, it would be a better idea to just replace the (4) 1w 22k SMT resistors under the main cap with a 2w 88k THT resistor and space it from off the pcb slightly then add electrical tape to the back side of the oscilloscope aluminum frame to prevent the resistor from coming in contact with it. Here's a close part:
www.digikey.com/product-detail/en/te-connectivity-passive-product/RR02J91KTB/A138369CT-ND/9371770
so what happened to those other videos you promised!
Sir digital oscilloscope freezing problems sir
Unbelievably, my DSO-X just fried and I found the PSU has exactly the same damage marks. For those who'd rather just replace the PSU than repair the fried one, has anyone figured out a suitable replacement?
Feel free to read the link in the description.
www.eevblog.com/forum/repair/dso-x-3024a-power-supply-defect/?all
There are plenty of PSU options listed.
@@SalvagedCircuitry Yeah I checked your list. None of them are drop-in replacements in the sense of having identical output connectors. I see the default approach is to go ahead and modify the scope's harness to adapt to the replacement PSU, so I'll do that.
I subscribed but I reserve the right to use the mute button :P
Hahaha. Go right ahead.
Hi
i just hope my oscilloscope doesn't have to go through that.