Author Topic: Fluke 289 not quite sorted.  (Read 67809 times)

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Offline MihaiV

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Re: Fluke 289 not quite sorted.
« Reply #225 on: March 12, 2022, 08:30:53 pm »
Correct, the configuration file from post 163 is set with an ARM7 core, while the MXS datasheet says it uses an ARM9. But won't the setting be the same (base address, size, organization)? (I have a 287, by the way).
 

Offline maximalcho

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Re: Fluke 289 not quite sorted.
« Reply #226 on: March 13, 2022, 07:43:14 am »
Yes the flash settings are the same but when you change core type they return by default and you have to set them again.Maybe changing core type from arm7 to arm9 doesn't matter but i changed it just in case.
My English is not very good I hope you understand what I mean. :)
 

Offline MihaiV

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Re: Fluke 289 not quite sorted.
« Reply #227 on: March 13, 2022, 12:52:29 pm »
Your English is good, I understood with no problems!
I switched to ARM9 too, re-configured the flash settings.
Here is a fun fact though: I tried reading again the entire chip and got the same error with ramCode and all, and after that it struck me to try it without using the target ram. I unticked the setting and now I can read the chip, without any command-line magic! And fairly quick too, only 23 seconds.

I also tried to program it with AnJu's file but the chip is locked. I get a "Block lock-bit detected!". I guess i have to erase the entire chip to unsecure it, right?
 

Offline MihaiV

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Re: Fluke 289 not quite sorted.
« Reply #228 on: March 17, 2022, 07:17:00 pm »
I must have done something really wrong here...
I erased the entire flash yesterday and then I was able to program the first part of AnJu's binary (2.fs 0x10040000.bin).
Without using target RAM it only took 14592 seconds, but it completed successfully (in attachment). Today I tried to upload the remaining part ( 3.FIS directory 0x107E0000.bin ) but I couldn't! I got the same "Block lock-bit detected!" message on the J-Flash.

Prepairing for another 4h of uploading, I erased the flash again to "unlock" it, to flash the FIS directory and after that the rest of the fs. But I couldn't do any of it! The flash is empty, I can read it back, but I can't even write the initial content!

Is there a way to erase those lock-bits? Did I brick it?
 

Offline ehobby

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Re: Fluke 289 not quite sorted.
« Reply #229 on: March 18, 2022, 09:06:44 pm »
Hopefully just a quick question...  Has anyone come across a datasheet or app note for the LTC939CS regulator used in the 289?  I have not been able to find anything on the web except the fact that lots of third parties stock it.

Thanks
 

Offline MihaiV

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Re: Fluke 289 not quite sorted.
« Reply #230 on: March 19, 2022, 08:20:28 am »
Hi,

If it is U10 you are refering to, it is a LTC2415-1, and it is a sigma-delta ADC, 24 bit.
The second row contains the actual part number.
Datasheet in attachement.

MihaiV.
 

Offline ehobby

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Re: Fluke 289 not quite sorted.
« Reply #231 on: March 20, 2022, 03:36:00 am »
MihaiV,
Thanks for responding and providing the datasheet for the LTC2415-1.

I actually was looking for the datasheet for the LTC939CS which seems to be near impossible to find. Been hunting this for quite a while. Have looked in Linear databooks from around 2000 and all over the web, including the Linear/Analog website.

Thanks
 

Offline maximalcho

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Re: Fluke 289 not quite sorted.
« Reply #232 on: March 20, 2022, 09:02:23 am »
Hi MihaiV,
You can try what i did,First try to flash dump from kjk24 then from AnJu but from AnJu dumps i use only one file but I don't remember which of the two files I used fs or fis.There is also a high probability that the flash chip has bad blocks.Why waste your time and not order a new ram memory and a new flash chip according to what you describe your problem is in one of them or both.Did you try to reflow ram ic ?
« Last Edit: March 20, 2022, 09:09:22 am by maximalcho »
 
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Offline kaiser

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Re: Fluke 289 not quite sorted.
« Reply #233 on: March 20, 2022, 10:22:53 am »
I must have done something really wrong here...
I erased the entire flash yesterday and then I was able to program the first part of AnJu's binary (2.fs 0x10040000.bin).
Without using target RAM it only took 14592 seconds, but it completed successfully (in attachment). Today I tried to upload the remaining part ( 3.FIS directory 0x107E0000.bin ) but I couldn't! I got the same "Block lock-bit detected!" message on the J-Flash.

Prepairing for another 4h of uploading, I erased the flash again to "unlock" it, to flash the FIS directory and after that the rest of the fs. But I couldn't do any of it! The flash is empty, I can read it back, but I can't even write the initial content!

Is there a way to erase those lock-bits? Did I brick it?

Try shorting J4 jumper at power up to put into boot mode and try and read flash with J-Flash and the init script and use target ram ticked..  Hopefully you won't get any errors..  If no errors, then you should be able to write...


K..
 
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Offline MihaiV

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Re: Fluke 289 not quite sorted.
« Reply #234 on: March 22, 2022, 07:09:40 pm »
Hello everyone,

Here is what I did:
- Thank you Kaiser for the J4 tip: shorting it during power-up (and removing it after 2s) allowed me to use the target ram setting in Jflash. I am now able to upload binaries in the flash.
- The chip being blank, I uploaded first the "3.FIS directory 0x107E0000.bin" from post 83, followed by "2.fs 0x10040000.bin". After a re-power, nothing happened. The splash screen that used to appear before my gray screen did not come up and the green led remained constantly on.
- I erased the flash again and uploaded my initial flash contents (with application and bootloader). Now it was doing the splash screen and the gray screen after it. The led turns off, so I am back to my initial state.
- I attempted to upload only the fs ("2.fs 0x10040000.bin") and to keep my initial bootloader, but I couldn't write those sectors because (maybe?) they were not blank. So I erased only the sectors that would be occupied by the fs, starting from 0x10040000 until 0x107DFFFF.
- After erasing the selected sectors, I uploaded the "2.fs 0x10040000.bin".
- Repower and ... IT BOOTS!!!
- It went past the splash screen, greeting me with the lost date and time message (the back-up cap being gone). The buttons work, the beeper works, I can see the meter info (photos 1 and 2) ... awww, it's awesome!!

But hold on to your hats, it's not over yet!
I had the selector on VAC, and sure, it displayed 0.0000VAC (photo 3).
Check photo 4 on the mVAC: blank! Same on the VDC, Ohms A/mA and uA.
But on the mVDC it displays Ohms and on Diode/Cap it goes in uA. Lead detection works, by the way.

Continuity does not beep and Ohms measurement has a ~2.2K offset. Once eliminated with relative mode it measures resistors accurately.
This appears related to the weird voltages i measured during reverse engineering the rotary switch (in post 185).

Voltages available on pin 95 of MSP are not monotonic with rotary switching and some positions provide overlapping voltages.
Will investigate this now, starting with voltage measurement at the voltage divider input, followed by providing voltages externally, to identify the voltage range for each meter function.

I hope I don't have a swapped rotary encoder, I would be screwed! Since the meter works with a standard 287 software, is is clearly a 287 board swapped in a 287/Nuc case.

Thank you Kaiser, maximalcho and everyone for al your tips and advice, I wouldn't have don it without you!
Now, to deal with the rotary...
 

Offline MihaiV

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Re: Fluke 289 not quite sorted.
« Reply #235 on: March 22, 2022, 07:10:24 pm »
And the following photos...
 

Offline MihaiV

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Re: Fluke 289 not quite sorted.
« Reply #236 on: March 22, 2022, 07:11:55 pm »
Here is the one on VAC...
 

Offline MihaiV

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Re: Fluke 289 not quite sorted.
« Reply #237 on: March 22, 2022, 07:13:37 pm »
And mVAC.
 

Offline maximalcho

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Re: Fluke 289 not quite sorted.
« Reply #238 on: March 23, 2022, 08:05:38 am »
I forgot about the damn jumper. Good thing at least Kaiser remembered.I'm glad you made the multimeter too.
 
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Offline kaiser

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Re: Fluke 289 not quite sorted.
« Reply #239 on: March 23, 2022, 10:45:38 am »
And mVAC.

Is it possible that the aligning holes on the rotary switch which mates to the rotary housing is out by 180° ?  I realise that one of the locating holes is larger than the other but possibly with enough force it will mate incorrectly..

P.S  Well done on your progress thus far..

K..
 
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Offline MihaiV

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Re: Fluke 289 not quite sorted.
« Reply #240 on: April 09, 2022, 07:45:31 pm »
Hello,

I had to delay the repair for a while, but I'm on it again. I started troubleshooting the weird selector switch operation.
First, I checked all contacts, on PCB and the moving parts, to ensure there is no oxidation or faulty contact. No problems here.

In a previous post (nr 185) and with the help of Towlerar I focused a little on the voltage divider used for range selection, so I checked what voltage is required for what function. Also useful to see if the software does what it should.

I took a multi-turn pot (1K, the panel mount type), tied its ends to GND and the 2.5V reference and the wiper to R19, going to pin 95 of MSP.
All ranges are detected, and the results are in the table below. Measurements were made with a meter from work, set on Hi-Z. Putting 10Meg in parallel with 1Meg of R19 introduces a bit of error.

Fit the moving parts back (by the way, there is no way to assemble it wrong, maybe with the hammer, but there were no signs of brute force) and measure the output on each range (attached in the second table).

I noticed that all were a bit higher than it was needed. First, I thought that there was some flux residue under the first few resistors, so i cleaned them again, but there was no change. Using the 10Meg input also didn't change a thing. I wanted to fit a higher resistance above the first resistor in the divider, on the 2.5V side, an then it struck me to check R19. Out of the circuit, it was open!

I imagine I must have broken it myself when I desoldered it first time. Replace it with a new one and it works !!!
All functions are on their proper positions, none missing! Put the thing back together, to check the enclosure effect (meaning that things work when open and not when in their enclosure) and it works, all of it! Wow, I thought I wouldn't make it!

Big thanks to everyone that contributed to this forum and tipped me with great advice!

Here is the list of faults in my unit:
- Slightly corroded back-up capacitor. Remove and replace (don't know with what yet, but I saw a topic on it in the forum).
- Faulty solder joint under the MXS: showed the splash-screen only when pressing on it or warping the board. Reflowed the thing with liquid flux and hot air.
- Faulty MXS crystal, 32.768 KHz. Not oscillating, maybe cracked (?). Replaced with something else, and it runs. Make sure you use a low capacitance probe on it.
- Corrupted/wrong application. Fixed using the binary from AnJu, only the "2.fs 0x10040000.bin" file, I kept my own bootloader. Make sure you short JP4 at power-up. This removes the lock-bit problem when using the Jlink to write/delete the flash memory.
- Faulty resistor at the rotary switch, showing wrong voltages to the MSP430. Most likely because of me, not a fault from the beginning.

Glad to save it from the landfill!

I wanted this meter for my little brother, he got in the Polytechnic University last year, at some kind of light version of the electronics faculty, and I want him to start working with actual parts and tools, not only with paper and simulations. He saw it, but he doesn't know it's for him (he calls it "the yellow dumpster"). I can't wait to see his face when I'll give it to him!  :-DMM

Thank you everyone!
« Last Edit: May 01, 2022, 08:24:03 am by MihaiV »
 

Offline lern01

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Re: Fluke 289 not quite sorted.
« Reply #241 on: November 19, 2024, 10:20:44 am »
Expected non-working LCD to Working DMM.
This way when it works you know for sure the LCD works.

Other way around when good LCD attached to defect DMM, you know screen from new unit is good, but if it does not work, you know the Mainboard of the defect DMM is broken. But till that moment you still do not know if the suspected LCD is broken.

My 2 cents



I did as you suggested. The LCD from the 289 woke up fine when connected to my good DMM (287).

It seems that the LCD driver circuit on the 289 is no good. I noticed that one of the crystals had a low amplitude (200 mVpp) the way I measured it. According to the Fluke 27 Service Manual a similar 32.768 kHz crystal should measure 600 mVpp or more.:

  • 4. Connect either an oscilloscope or frequency counter, using a low-capacitance probe,
    to pin 54 of U1 or to the junction of C17 and Y1 (the crystal). A 32.768 kHz sine
    wave with an amplitude of approximately 600 mV peak-to-peak should be present at
    the junction of C17 and Y1 (3 V peak-to-peak at U1 pin 54). Note that U2 and the
    display will not operate if the clock signal is not present. If the clock signal is not
    present, the most likely causes are U1, Y1 or C17.

Can a missing (or low) clock signal be a part of the LCD problem when the rest of the meter seems to be working ok?


U1, C17, and Y1 are not in a functional circuit, and they seem to have nothing to do with the LCD circuit? Please advise, thank you!
 


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