Author Topic: Fluke 289 not quite sorted.  (Read 19549 times)

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Offline giosif

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Re: Fluke 289 not quite sorted.
« Reply #150 on: July 28, 2019, 02:40:28 pm »
Hi,

Apologies for piggybacking this thread, but thought I'd take advantage of the attention the conversations here have had recently and also save creating another thread.
I recently purchased a Fluke 289 from our loved & hated online auction site and this meter not only has the screen broken, but it doesn't exhibit any signs of life.
I mean, if I press the power button, it turns green, but it stays that way and doesn't turn off (watching some videos online, I see the button led should turn off once the meter has completed booting).
Also, testing "on the blind" some functions like continuity didn't work (no audio output).
Finally, using the useful information contributed to this thread, I checked for serial communication on the J5 port, but there was no output of any kind (checked with the scope and the TX line is High all the time).

So, I started checking the other things mentioned here:
  • Y1 and Y2 are oscillating at the right frequencies
  • pin 1 on U13 gets power
  • all power rails are fine, with one exception: the 5V rail
  • another measurement that didn't match was the 2.5V, but that's the reference voltage, not a power rail.

Now, tracing the above problematic power rail got me to U17, which is responsible with generating the 5V.
The input of the regulator is getting 9V, so we're good there, but this regulator also has an ENABLE pin which is active Low.
And, you guessed it, it is always High.
As such, no 5V rail and, checking further down the line, no 2.5V voltage reference output from U15 either, since it is being powered by the 5V rail.
Next, I checked who is keeping the U17 ENABLE pin High and I traced the connection to pin 72 on U13.

And this is where I'm stuck at the moment, as I don't know what to do next, to determine what makes U13 keep pin 72 High.
I guess it could be that U13 is toasted or that it is waiting for some signal before turning on the 5V rail, but never gets that signal.

Anyone any suggestions, please?

Thanks!
 

Offline say

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« Last Edit: July 28, 2019, 09:45:52 pm by say »
 
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Offline giosif

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Re: Fluke 289 not quite sorted.
« Reply #152 on: July 29, 2019, 09:47:55 pm »
You may like to check this thread too.

https://r.tapatalk.com/shareLink?url=https%3A%2F%2Fwww%2Eeevblog%2Ecom%2Fforum%2Findex%2Ephp%3Ftopic%3D59991%2E0&share_tid=59991&share_fid=25658&share_type=t

Thank you, say!
That is a very useful thread but which, unfortunately, significantly diminished my hope I might be able to resurrect this meter: all three caps - C46, C55 and C92 - measure short across their terminals (and are all tied to the battery negative).
Although, I don't know... I find it strange this tends to happen in most cases with a dead 289...
Also, these three caps are located quite apart from each other on the board and I am trying to imagine what kind of failure can lead to this short measurement across each of them.
Could it be a common power rail that, once the NXP goes bad, gets somehow shorted?
Let me ask on the other thread, then.

Thanks again!
 

Offline kjk24

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Re: Fluke 289 not quite sorted.
« Reply #153 on: December 28, 2019, 10:27:09 am »
Hi,

here a pic of the PCB under MSP430, i replaced it on two meters and reprogrammed it via jtag this works fine.
i replaced also on both bad units the MC9328 but i made no foto  :-- of the pcb i forgot it shame.

the tree units in my lab have PCB Rev. 014, 015, 027
my meters are switching on and the power led stays on, i have no console output and no communication on spi,rs232, no lcd
the specker make a short sound at switching it on.

there are two spi communication path from  MSP430 to MC9328 and from MSP430 to the Analog part of the meter for switching Analog switches adg714.
MSP430 to MC9328 8Bit 2Mhz
70 SDI
69 SDO
68 clk
67 cs

MSP430 to ADG714
48 clk
50 SDI
49 SDO

i try to find out howto enable the ram to get excess from the jtag of the MC9328 to flash the fw to the flashchip via j-flash .
attached readout address spaces from a working unit.

iam searching for mx1flash utility for programming the external flash connected to MC9328
 




« Last Edit: December 29, 2019, 10:10:50 am by kjk24 »
best regards
kai
-------------------------------
I7 &
E4 1.19.8
 
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Offline kjk24

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Re: Fluke 289 not quite sorted.
« Reply #154 on: January 03, 2020, 02:45:36 pm »
new fotos of the MC9328 & the Falsh & RAM
best regards
kai
-------------------------------
I7 &
E4 1.19.8
 
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Offline kjk24

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Re: Fluke 289 not quite sorted.
« Reply #155 on: March 25, 2020, 02:29:22 pm »
i replaced on one board the flash chip with a empty one,

tryed to flash the contense from other peoples flash and my extractions to 0x10000000 with j-flash and j-link-edu programmer.
loadfile "Z:\data.bin", 0x10000000
The j-link sw returned error unspecific -1.

in the i.MX Development Tools User Guide is a description how to doit, but i have not such a file to test it:
in chapter: 2.1.3 Flashing Bootloader
"BSP/Bootloader/bin/AMDFlash/programBoot_b.txt"

who has knowlage how to write the bootloader iguess its redBoot @ 0x10000000 in the flash chip ?
please let us know  :-+

other:
i add the bootloader jumper, and open a terminal program "9600-57600/8N1", and start the device connected to the rs232 pins next to the speaker.
it will respond with ":" when you type "a"
that means the chips first stage bootloader is alive.
best regards
kai
-------------------------------
I7 &
E4 1.19.8
 


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