Video Repair of PXI-2596, PXI-4461 & PXI-4071 Modules - Page 1
Forum section: electronics / testgear

author: Hugoneus
author_rank: Frequent Contributor
timestamp: October 04, 2015, 03:44:17 am
content: You can watch it here: [32 Minutes]youtu.be/dAnMCgdRAHkMore vidoes at The Signal Path:http://www.TheSignalPath.com

author: TheSteve
author_rank: Unknown
timestamp: October 04, 2015, 05:36:50 am
content: Another great video Shahriar - thank you for posting it. Do you have Pooch helping when you solder stuff, an extra set of paws can be pretty useful.Shame the DMM didn't come back to life. The memory chip you replaced is ram I assume. Have you spent any time to see if the module is killing the power supply or is it the data bus itself? You've likely done more troubleshooting off camera - maybe walk us through what you have all done.

author: bktemp
author_rank: Super Contributor
timestamp: October 04, 2015, 06:22:33 am
content: In the video you said the missing component looked similar to the one on the other side. And this looks like a Flash memory, most likely containing some firmware, or the FPGA bitstream.If you replace it with a new one, the firmware is still missing. If this firmware controls and initializes the PCI controller this could explain why the bus is not workling.

author: Hugoneus
author_rank: Frequent Contributor
timestamp: October 04, 2015, 04:12:18 pm
content: Quote from: bktemp on October 04, 2015, 06:22:33 amIt is possible that some firmware is missing, unfortunately I don't have the original firmware...

author: TiN
author_rank: Super Contributor
timestamp: October 04, 2015, 04:33:21 pm
content: Perhaps you can read firmware from your other module and try flash that one. There is little chance PXI side of things is unified, so firmware from other module would work.Or maybe NI can send you the correct one?

author: lukier
author_rank: Unknown
timestamp: October 04, 2015, 04:45:50 pm
content: Do you have high-res photos of these cards by any chance?I'm curious what ADC and DACs they use on the PXI-4461. 24 bit DAC is actually something spectacular, so I strongly suspect they use cheapo audio AD/DA! These things have horrible DC specs, so often they don't even mention INL/DNL and ENOB in the datasheets (not to mention gain/offset temperature drifts).

author: Hugoneus
author_rank: Frequent Contributor
timestamp: October 04, 2015, 10:35:19 pm
content: Quote from: TiN on October 04, 2015, 04:33:21 pmI am not sure if this is easy to do... My other PXI modules don't use the same PCI bus IC...

author: TheSteve
author_rank: Unknown
timestamp: October 05, 2015, 02:27:14 am
content: Well if it is a flash chip I'd say you're much stuck unless you can find another DMM module and remove/read the flash chips to copy the images. I would have thought a card with a blank flash would not cause problems on the bus. Perhaps it reads some code from the first flash and then gets stuck looking for the second one.

author: Vgkid
author_rank: Super Contributor
timestamp: October 05, 2015, 03:19:18 am
content: What is the voltage reference in the 4071?

author: Hugoneus
author_rank: Frequent Contributor
timestamp: October 05, 2015, 05:28:15 pm
content: Quote from: Vgkid on October 05, 2015, 03:19:18 amLTZ1000

author: guido
author_rank: Regular Contributor
timestamp: October 05, 2015, 05:32:11 pm
content: I would have done the repair of the relay module differently:put the connector on the third, unused, sectionconnect the transistors (or FETs, can't remember) to the equivalent transistor pads going to the connectorConnector mounted sturdy on the pcb and just six (or seven with gnd?) easy connections.Just my 2 centsEdit: too bad that was not possible. Looked that way but i guess you checked.

author: Hugoneus
author_rank: Frequent Contributor
timestamp: October 05, 2015, 06:01:57 pm
content: Quote from: guido on October 05, 2015, 05:32:11 pmThat was not possible. The empty connectors aren't actually empty. The connections go to the other MOS switches which are already occupied. The connections are designed with some other type of microwave switches in mind.

author: Vgkid
author_rank: Super Contributor
timestamp: October 05, 2015, 07:10:52 pm
content: Quote from: Hugoneus on October 05, 2015, 05:28:15 pmThanks, that is what I assumed it was.

author: AF6LJ
author_rank: Unknown
timestamp: October 05, 2015, 07:52:40 pm
content: Good video.Good luck with the DMM module, but I am not holding my breath.

author: BFX
author_rank: Frequent Contributor
timestamp: October 05, 2015, 10:39:41 pm
content: Thank you Shahriar for another instructive video. It's very helpful for lot of people here I thinkDid you try thermal camera scanning with power of this board ? Only to be sure if isn't bug somewhere in power lines.

author: free_electron
author_rank: Super Contributor
timestamp: October 05, 2015, 11:05:24 pm
content: PXI ? SET IT ON FIRE !!#$%(@*#$% overpriced craptional instrucrap crap.

author: Monkeh
author_rank: Super Contributor
timestamp: October 06, 2015, 12:07:35 pm
content: Another showing of the rare and underappreciated oscillocat

author: Hugoneus
author_rank: Frequent Contributor
timestamp: October 06, 2015, 08:32:30 pm
content: Quote from: free_electron on October 05, 2015, 11:05:24 pmHaha! Yeah... that DMM is listed for $3.3k.

author: rx8pilot
author_rank: Super Contributor
timestamp: October 06, 2015, 08:39:46 pm
content: Quote from: free_electron on October 05, 2015, 11:05:24 pmI like PXI and LabVIEW.Sent from my SAMSUNG-SM-G890A using Tapatalk

author: c4757p
author_rank: Super Contributor
timestamp: October 06, 2015, 08:41:18 pm
content: It's so overengineered! That microwave switch module had what - an FPGA, a PCI interface chip, like three memories, some unidentified SSOP, some microcontroller-looking thing... did I miss anything? All to switch relays! Even if they want it to be PCI only, it doesn't take that much to slap something onto a PCI bus, pretty much a lone FPGA with no external memory other than the main flash can do that. The FPGA can also generate the relay control signals directly, store the actuation counts back into the flash, etc...

author: rx8pilot
author_rank: Super Contributor
timestamp: October 06, 2015, 11:19:31 pm
content: Quote from: c4757p on October 06, 2015, 08:41:18 pmI won't argue that. I will say that as I have been researching and learning a lot about automated T&M for design validation and production and National Instruments has been a great thing. If you look at it from the perspective of someone like myself that will use LabView with PXI hardware and stand-alone T&M - the integration is hard to beat. I can rather quickly setup and automate a test that was taking 30min to do and required me or some other qualified engineer to do and smash it down to 1 minute and require next to no skill at all. The time savings of automated and integrated tests that I can have housed in a single chassis is enough to justify the cost of a PXI system.In my previous careers, I have always 'over purchased' what many called over engineered. It made me and my companies the quickest most reliable in our field - and the most profitable. I am a relative newbie in electronics design and manufacturing, but I can already tell that buying the high-end pays for itself. I have not yet purchased my PXI system, but I am confident the $ that goes in will be $$$ that comes out.It may be never that I need a 26Ghz relay on the PXI system.....

author: c4757p
author_rank: Super Contributor
timestamp: October 06, 2015, 11:23:01 pm
content: And yet theexact same functionalitycan be implemented with significantly less faff. What does any of that have to do with whether or not the modules are overengineered?I'm not saying anything against the PXI system existing. It looks quite nice, I'd love to have one. It just looks like they made it cost about 10x what it has to.

author: rx8pilot
author_rank: Super Contributor
timestamp: October 06, 2015, 11:49:02 pm
content: The over-engineered part raises the price of the modules. While I wish they were less expensive - I voted to pay extra to have a single, compact, totally integrated test system that is easily operable by a low-level technician. Having an immobile bench with a stack if 8 instruments all connected to a laptop is not nearly as friendly.You say....Quote from: c4757p on October 06, 2015, 08:41:18 pmThe most glaring problem with over-engineered T&M is that the price makes it scary. My point was - who cares if it is over engineered if it solves all of my problems and I don't have to worry about it. The problem with the traditional route is the significant increase in labor costs since it needs a much better technician or engineer to operate. The over-engineering buys me a solution that cost very little to operate every day. I can put a PXI chassis on a cart with a bed of nails, roll it over to the end of the P&P line and have the operator running testing and programming of the PCB's as they come out. At that point I don't care if the relay card is controlled by FPGA's - I am happy that I don't have a $75k/year technician/engineer testing PCB's.Hopefully that makes sense.

author: c4757p
author_rank: Super Contributor
timestamp: October 06, 2015, 11:51:53 pm
content: Sure, of course, it can be overlooked, and clearly is, by many people. Just saying, all that stuff to drive some relays is a bit comical.

author: rx8pilot
author_rank: Super Contributor
timestamp: October 06, 2015, 11:58:27 pm
content: I agree.There is a company that I used to buy very expensive video terminal equipment from. They had many general purpose designs that could be used for many purposes. What you ended up with was a product that was totally appropriate if it was the most sophisticated in the series. When you look at the entry level configuration - it was hilarious. Sometimes a few FPGA's were doing what could be done with a single microcontroller. The I/O architecture required all three FPGA to be doing a teeny tiny bit of work.The justification was the the cost of the extra components was less than the cost of whole new dedicated and optimized design. Volume was rather low, so I believed that explanation.

author: Bud
author_rank: Super Contributor
timestamp: October 07, 2015, 01:00:14 am
content: Speaking of the relays, at 8:20 it was said they have remarkable repeatability because they are mechanical, not solid state, which i find hard to believe (that mech ones are better)

author: tec5c
author_rank: Frequent Contributor
timestamp: October 07, 2015, 01:59:54 am
content: Quote from: free_electron on October 05, 2015, 11:05:24 pm

author: rx8pilot
author_rank: Super Contributor
timestamp: October 07, 2015, 04:53:34 am
content: Quote from: Bud on October 07, 2015, 01:00:14 amAt 26Ghz....a very carefully designed and constructed contact probably works better than silicon. It is rather far out of my understanding, perhaps Shahriar can help decode that one. I have worked on many projects (as mechanical engineer) but was watching over the shoulders of the EE's dealing with 3Ghz digital and the delicate nature of that work. At 26 Ghz, its hard to imagine how delicate that is.

author: RFerri
author_rank: Newbie
timestamp: April 02, 2025, 03:31:43 am
content: I will soon open a channel on YouTube, where I will post photos of equipment and so on. If anyone needs photos of equipment, then write in what form these photos should be. I have a large collection of National Instruments.