Fluke 8846A repair shenanigans.

[ASEMechanic]

dmm4040 does have the USB while Fluke 8845A does not so in that regard dmm4040 is closer to 8846A/dmm4050

If I am not mistaken the boards on 8845A and 8846A are not identical. Well, they are but there are a couple of missing chips on 8845A
which might be the USB controller. I might be totally wrong...

I have not seen the inside of DMM40xx....

Gotcha. Well, it was a thought anyway.

As it turns out, Noritake Elec. *WILL* sell just the MN25664J display directly through them. 8-12 week lead time and ships directly from Japan. Price? $153.00 for 1-9 units and $135.20 for 10+ units.

Anyone with weak displays interested in a group buy?? 

[alligatorblues]

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

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

If you send a 884xA in for calibration (~200$), Fluke will make any small repairs necessary at no charge. Last one I sent in they reflowed the solder joints on front terminals, and updated to latest firmware, both at no charge. But you must have Fluke put on the quote to update firmware, or it might not get done, as was the case with a different meter I sent in for cal.. I had to send it back to get the firmware.

Fluke does not give out firmware, because if you buy the front cover, keypad, and what not, you can make a 8846A from a 8845A. They are nearly identical, except for the cosmetics and firmware. If you complain about no free firmware, Fluke will just tell you to shove it, like, "We're Fluke. We don't have to care. We have no competition."

They've even done some minor repairs on 732Bs when I sent them in for cal..

[gamalot]

dmm4040 does have the USB while Fluke 8845A does not so in that regard dmm4040 is closer to 8846A/dmm4050

If I am not mistaken the boards on 8845A and 8846A are not identical. Well, they are but there are a couple of missing chips on 8845A
which might be the USB controller. I might be totally wrong...

I have not seen the inside of DMM40xx....

The difference between DMM4040 and 8846A I can see from the outside is the color of the case, front bumper, handle, and the printing on the front panel (including the glass window and buttons).

I opened the case to see what's different inside (clear the dust by the way), and I saw an 8846A mainboard inside my DMM4040.

I uploaded some pictures here, you can also find high-res pictures of the board on github https://github.com/gamalot/DMM4040-Pictures .

[Kleinstein]

They have tighter specs for the 8846 compared to the 8845. So there can also be  differences in the quality of parts (e.g. better selected resistors or reference) and maybe testing of the whole PCB (those that did not so well in the tests get used for 8845). From the outside a new LM399 looks the same as one with a 3 month burn in and tested for noise.

[gamalot]

They have tighter specs for the 8846 compared to the 8845. So there can also be  differences in the quality of parts (e.g. better selected resistors or reference) and maybe testing of the whole PCB (those that did not so well in the tests get used for 8845). From the outside a new LM399 looks the same as one with a 3 month burn in and tested for noise.

I'm sure they'd save the money if they could.

---

You can see that J10 and J13 are populated in the picture of Illya's 8846A, but not in my DMM4040.

[analogRF]

Tonight is Chinese New Year's Eve, I gave myself a gift, upgraded my Tektronix DMM4040 to Fluke 8846.

Just about half an hour ago, I happened to see this topic, and then saw that someone had uploaded firmware to xDevs.com, so I decided to try my luck.

Now I am very happy, as you can see in the pictures it can correctly measure capacitance and temperature, those are not features of DMM4040 nor 8845.

Thank you so much everyone! 

i am still wondering how this could have worked? FW for 8845A and 8846A are the same, also the FW for 4040 and 4050 were the same so I think there must be something on the board or in the flash that identifies the model number and it should not be erasable and modifiable by a FW upgrade...

So did the fluke FW complately erased the flash including whatever identified the unit as dmm4040 and replaced it with 8846A?

Do you see FLUKE logo at startup now?

[gamalot]

I think all the information is overwritten during the firmware update, except the calibration data.

[analogRF]

I think all the information is overwritten during the firmware update, except the calibration data.

do you know what was the OutG FW version of the unit originally? was it below 2.10?

and one last question, are the Cap and Temp measurements in spec? They should not be I guess...

[gamalot]

I don't remember the exact original version number, but I'm sure the original DMM4040 firmware had a higher version number than the 8846A I flashed into it.

As for the capacitance and temperature test functions, of course they have not been properly calibrated, and some default values should be used. I found some capacitors and tested them. I can see that comparing the 34465A and the LCR meter, the results of the DMM4040 have very large errors in certain ranges. I didn't do temperature measurements because I don't have the right equipment.

[Miti]

I can see in the xDevs hi res pictures, there are two SOIC8 ST devices with labels on top. I assume they are configuration devices for the FPGAs. Has anyone tried to dump those and compare a good one with a bad one? Is it possible that something is corrupt there?

[charlyd]

Hi is there any progression on the bootup...initializing...... error?