Fluke 8846A repair shenanigans.

[Jwalling]

Hmm...
Seems like this could be a common problem.

[Johnny10]

What does it cost to send them to Fluke for service?

Or is that a question not allowed in the repair forum. :-)

[GreyWoolfe]

What does it cost to send them to Fluke for service?

Or is that a question not allowed in the repair forum. :-)

At least you didn't ask that question in the TEA thread!!

[DC1MC]

What does it cost to send them to Fluke for service?

Or is that a question not allowed in the repair forum. :-)

The cost of sending them to Fluke for service is acceptable, on the other side, the cost of the servicing, this is what kills you .

[Jwalling]

What does it cost to send them to Fluke for service?

Or is that a question not allowed in the repair forum. :-)

The cost of sending them to Fluke for service is acceptable, on the other side, the cost of the servicing, this is what kills you .

 

Yep. IME, it costs about as much, if not more, than a used one in good working order. The four I have appear to have the same fault, but one is a bit different in it's behavior... More tomorrow.

[Johnny10]

Yea, why did I even ask 

I should know better! Waaaaayyyyy too expensive.

I have two units with same error but one has all power rails working properly and one has shorted -15 and +15.
So same error covers a lot of different issues.

[giosif]

Anyone getting bored of one of these sick puppies, I'd be glad to alleviate the burden. 

[coromonadalix]

Sad to see theses meters having problems and Fluke does'nt acknowledge a thing

[TiN]

What would you want Fluke to do? I'm sure they will help you with repair for 90% of new unit cost 

So far my experience with this 8846 just tend to consider it as overcomplicated design filled with unfriendly firmwares. BGA FPGAs with NIOS SoPC, no way to backup firmware, Fluke withdrawal of their own published FW and poor service documentation. Sure I'd accept that in meter like 8508A, but not in benchtop unit like 884X.

[Jwalling]

Yea, why did I even ask 

I should know better! Waaaaayyyyy too expensive.

I have two units with same error but one has all power rails working properly and one has shorted -15 and +15.
So same error covers a lot of different issues.

You're probably right. I can see the self test routine:
1 to 199: Run a whole bunch of self tests.
200: If anything fails, sit there and look stupid.

So the four units I have were bought by a friend of mine who brings me lots of repair work from a Govt. auction. Normally, he doesn't buy test gear, but other industrial equipment (hardness testers, etc)
https://www.govdeals.com/index.cfm?fa=Main.Item&itemid=17539&acctid=2863

If he had asked me about them before buying, I would have told him to stay away!

Symptoms:

1. All hang at the init screen.
2. When there is a USB thumb drive plugged in, three of them access the drive at 2 seconds and 8 seconds after powering on. No further accesses are done after that. The fourth one accesses the drive at 2 seconds, then at 3 second intervals over and over forever.
3. All voltage rails are verified and correct.
4. None respond to a GPIB scanning
5.All connect to LAN, and activity pulses can be seen at two second intervals. One time I saw one of them connect to my Asus router and get an IP address. I was unable to get it to repeat this though...
6. I never see any data going across the opto-coupler transmitter at DS3. The other one is transmitting a steady stream of pulses. I'll have to check whether the receiver is getting them, but you got to pull the board or remove the cover to access it. @ TiN: Does this sound like yours?

EDIT: The data stream from DS2 is making it across fine. Whether the data is correct, though...

[Jwalling]

Yea, why did I even ask 

I should know better! Waaaaayyyyy too expensive.

I have two units with same error but one has all power rails working properly and one has shorted -15 and +15.
So same error covers a lot of different issues.

Shorted to GND? Do you have a 4 wire DMM?

[Johnny10]

The 15 V rail sits at 2.18V the -15 at 0.434V

Found a comparator, IC LM393, that is running over 200 degrees F, on the second unit only 87degrees.
Will be investigating that today.

[Shock]

Tin these look under done, please bake yours more.

Might be something to look at I cannot see from the thermal image what temp the right hand one is at. Did you check them and are those tantalums between?

Did you freeze spray that area at all? You may have hit a cap.

[Jwalling]

Tin these look under done, please bake yours more.

Might be something to look at I cannot see from the thermal image what temp the right hand one is at. Did you check them and are those tantalums between?

Did you freeze spray that area at all? You may have hit a cap.

A better pic you can zoom in on:
https://xdevs.com/doc/Fluke/8846A/img/fixed_in.jpg

[HighVoltage]

I used to have a 8846A because it was so much praised here on eevblog.

My unit was bought used with a very weak VFD, but I thought that would be an easy fix.
I tried forever to get a new VFD from Tektronix or other sources and I finally gave up and let go of the instrument.

[TiN]

All power on my 8846 is fine, nothing cooking or shorted. It is not relevant to the "init screen hang" issue, because meter should boot even with inguard section completely unpowered (removed transformer cable from inguard).

Jwalling, yes, there is no life on optos from outguard to inguard. There is slow square wave on pair from inguard to outguard (perhaps just heartbeat signal).
I have tried so far things like:
* Replace RJ45 magnetics and Eth phy (suspected dead LAN input, that get NIOS CPU in FPGA stuck waiting) = no help.
* Replaced outguard SDRAM = no help
* Replaced outguard FPGA (bought new Cyclone from Digikey) = no help
* Freezespray bunch of stuff around  = no help anymore. Originally it helped and made meter work randomly for shortime.

When it was working, it took about 10-20 seconds to boot from init screen, and you can hear relay click after 2-3 sec from power on. Now it however does not click anything, just sitting silly.

Supervisor chip that drive reset to NIOS FPGA is ok, reset is correctly toggled high on power on. There is some life to SDRAM data pins, so it's doing something.
I tried to probe RS232 chip in hope to find debug CPU console output, but there was no signals.

So far best shot would be to trace JTAG to the debug connector, and connect USB Blaster, to try if anything can be done from that side (perhaps read back NOR flash).
But it's a long shot, as we don't have binary image from the FW flash. 8846A update tool have only bits and pieces, but not the full dump binary.

[Jwalling]

What would you want Fluke to do? I'm sure they will help you with repair for 90% of new unit cost 

So far my experience with this 8846 just tend to consider it as overcomplicated design filled with unfriendly firmwares. BGA FPGAs with NIOS SoPC, no way to backup firmware, Fluke withdrawal of their own published FW and poor service documentation. Sure I'd accept that in meter like 8508A, but not in benchtop unit like 884X.

Re: Firmware for the Fluke version, have you tried contacting Erik?
https://www.eevblog.com/forum/testgear/fluke-8846a-anyone-that-got-the-updated-firmware-downloaded/msg1511872/#msg1511872

https://www.eevblog.com/forum/testgear/fluke-8846a-anyone-that-got-the-updated-firmware-downloaded/msg395578/#msg395578

Apparently, Fluke removed the update utility as too many people could not follow the instructions. Maybe they were bricking them?
assets.fluke.com/software/bench/readme.pdf

[Circlotron]

What does it cost to send them to Fluke for service?

Or is that a question not allowed in the repair forum. :-)

You could always couch it in terms of how much money you would be saving ;-)

[TiN]

Jwalling
You think where I got this one from?

[Jwalling]

Jwalling
You think where I got this one from?

Oh. sorry. I thought you were looking for firmware...

[Jwalling]

Doing some more poking around.

Cost to repair from Tek is $895.

The three units I have that behave the same with a USB drive attached, were from the University of Central Florida. All three had an RMA generated, but they never sent them in. Probably when they found out the repair cost. 

The fourth belonged to Entest Inc.

My gut feeling is that the firmware is probably corrupted on these. But it's just a guess...
Oh for the days when firmware was in PLCC sockets.

[Johnny10]

$895.00 Guess that answers my question !

About the price of a used 8846A DMM.

But it comes back calibrated also!

[coromonadalix]

895$  Each dmm  or the loot ??

[Kleinstein]

I think from the screen shots it should be clear that this is $895 per unit and excluding shipping and likely sales tax.  Given the rather high price some units might end up as display donors. The repair price is so high, because is in many cases this would be a board swap.

Firmware corruption could be possible, though I would expect a check sum test at the beginning and than a corresponding error message - just like TiN's 3458. Several units with a similar fault might make it worth to dig a little further.  As a broken communication should be caught by the ground based part, I would suspect trouble with the outbound part. Just in case one could do a test with an intentionally broken link - at least this should be caught, as it would be an expected failure mode (e.g. spider at the optical link).

[TiN]

Kleinstein
Usual NIOS people not thinking the same way as Motorola designers of 3458 FW. Why need to include debug/fault info for user, if we can just demo pretty Fluke intro bitmap on that lovely VFD, and ask user to pay for service?

Friend of mine tried to block opto on working 8846 and meter still was able to boot into main UI, just don't show any readings. So if meter no boot = outguard issues.