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#25 Reply
Posted by
GeoffreyF
on 13 Jan, 2019 17:02
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Your link goes to something my computer detects as a virus.
Mind explaining what is there at your link? Why should anyone click it?
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#26 Reply
Posted by
ElecSeb
on 13 Jan, 2019 20:44
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Just a normal page regarding end of internet, is around for ages (and often used)...
Page can be opened with any browser and tested with, KIS & Norton, so kinda curious what virus scanner/internet security you have...
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#27 Reply
Posted by
giosif
on 29 Jul, 2019 21:57
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Hi all,
I was just pointed to this thread, as it seems I am in the same situation as everyone else here: all three caps, C46, C55 and C92, measure short across their terminals (and are all tied to the battery negative - let's call it "ground" from this point onwards).
First, as I commented in the other thread, I find it strange for capacitors so spread out on the board to all exhibit this issue (not a an issue with the caps themselves, but an issue affecting them) and also in most cases with a dead Fluke 289.
Maybe they are all connected to the same power rail or data bus (and that somehow gets shorted whenever the NXP goes bad)?
Someone here mentioned they removed the NXP from the board and the short went away.
Can you please confirm that, with the NXP removed, the non-"ground" terminal of each of these three caps are linked to one another?
Also, is it just me but, having a really quick read of the NXP datasheet, it doesn't seem to have an internal storage?
If so, could we not just remove the dead NXP and replace it with a brand new one?
Thanks!
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Also, is it just me but, having a really quick read of the NXP datasheet, it doesn't seem to have an internal storage?
If so, could we not just remove the dead NXP and replace it with a brand new one?
Thanks!
I agree, it seems that the RAM is in separate IC's U25 & U27 and Flash is in separate IC U28, here is a review with high-res photos:
https://lygte-info.dk/review/DMMFluke%20289%20UK.html
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#29 Reply
Posted by
giosif
on 31 Jul, 2019 06:35
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I agree, it seems that the RAM is in separate IC's U25 & U27 and Flash is in separate IC U28, here is a review with high-res photos:
https://lygte-info.dk/review/DMMFluke%20289%20UK.html
Hmm... I suspect the challenge here is the reballing of the replacement NXP chip.
Nice, comprehensive review, BTW.
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#30 Reply
Posted by
mzacharias
on 31 Jul, 2019 16:26
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Hi all,
I was just pointed to this thread, as it seems I am in the same situation as everyone else here: all three caps, C46, C55 and C92, measure short across their terminals (and are all tied to the battery negative - let's call it "ground" from this point onwards).
First, as I commented in the other thread, I find it strange for capacitors so spread out on the board to all exhibit this issue (not a an issue with the caps themselves, but an issue affecting them) and also in most cases with a dead Fluke 289.
Maybe they are all connected to the same power rail or data bus (and that somehow gets shorted whenever the NXP goes bad)?
Someone here mentioned they removed the NXP from the board and the short went away.
Can you please confirm that, with the NXP removed, the non-"ground" terminal of each of these three caps are linked to one another?
Also, is it just me but, having a really quick read of the NXP datasheet, it doesn't seem to have an internal storage?
If so, could we not just remove the dead NXP and replace it with a brand new one?
Thanks!
I know this is crude, but it often works to feed a power supply at an appropriate voltage, and current limited as necessary, into the short, and simply wait a bit and see what gets hot.
If it's a true 0.0 Ohm short, then sure, no heat can be generated, but that's actually fairly rare.
I've found numerous bad microprocessors, chip caps, shorted tantalums, etc this way.
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#31 Reply
Posted by
giosif
on 31 Jul, 2019 19:56
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I know this is crude, but it often works to feed a power supply at an appropriate voltage, and current limited as necessary, into the short, and simply wait a bit and see what gets hot.
If it's a true 0.0 Ohm short, then sure, no heat can be generated, but that's actually fairly rare.
I've found numerous bad microprocessors, chip caps, shorted tantalums, etc this way.
Very good point, thanks!
Funny thing I've seen this done several times but, for some reason, it didn't really cross my mind in this instance (let's blame it on tiredness
).
I will try that.
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#32 Reply
Posted by
giosif
on 01 Aug, 2019 07:28
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How much current am I supposed to run through this part of circuit?
I set my power supply to 1.5V and, initially, about 0.8A.
I then gradually increased current all the way up to 3A, but still no signs of heating on the board.
Heck, at 3A, the cable I soldered to one of the short points started to heat up, yet, I could not detect any hot areas/components on the board.
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#33 Reply
Posted by
giosif
on 01 Aug, 2019 09:17
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So, I bit the bullet and did what I have been considering for a while (but wanted to exhaust all other options before that): I've reflowed the NXP chip (i.e. U26).
This is because the seller of this meter mentioned they had dropped it, thus ending up with a broken screen.
So, I thought the impact may also have affected the connection between U26 and the board.
I am happy to report that, following the reflow, I am seeing a positive evolution: the 5V rail is now coming up and, consequently, the 2.5 reference voltage is present too.
Moreover, on pressing the power button, the LED beneath it turns on for a while, then turns back off, with the meter still drawing some current - from the videos I watched on Youtube, this is the expected behaviour.
Also, if I press the power button once more, the meter turns off (very little current draw from the power supply it is connected to).
The other good news is that, with the rotary switch set to Resistance, if I measure the current between COM and V terminals, I see very exact current being generated.
Moreover, if I press the Range button repeatedly, the current changes to very specific values (e.g. 100uA, 1mA, etc.).
So, at least some part of the meter is alive now.
Now, the not-so-promising observations (all this is done on the blind, as I have no working LCD):
- if I switch to Continuity test mode and short COM and V terminals, there is no sound generated (and I checked outside of circuit that the buzzer is working).
- if I set the rotary switch to DCV, for instance, and insert a lead into the u/mA or A jacks, the meter should beep to warn me I got the lead in the wrong place - however, I'm not hearing any sound.
- (still not sure if this is really an issue or maybe a red herring) the shorts on caps C46, C55 and C92 are still present.
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#34 Reply
Posted by
giosif
on 01 Aug, 2019 12:24
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It's ALIVE !!!
What I've done since my previous post was to test the IR connectivity (thankfully, I had the IR-USB cable for it).
And the connection worked:
- I issued the "ID" command and got the correct response back
- I started issuing some "QM" commands in various settings of the rotary switch and the meter displayed at least the correct function
- Suspecting the meter might have some custom configuration settings from the previous owner, I went ahead and issued a "RMP" to reset to factory defaults.
And, surprise-surprise, the meter beeped when I turned it off.
So, of course, I then tested the input jack detection and I got the alert when the lead was inserted in the wrong jack.
Also, continuity testing is working now as well.
- Finally, I tested DCV readings from my power supply and they are pretty much spot on.
So, thanks to everyone here, it seems I've now got myself a meter in a fairly decent state (except for the LCD, of course).
Thank you all for your help!
Now off to finding a replacement LCD for it...
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#35 Reply
Posted by
say
on 01 Aug, 2019 14:31
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Congratulations on excellent results.
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#36 Reply
Posted by
giosif
on 01 Aug, 2019 19:39
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Thank you, say!
I wish it gives a boost of hope to yourself and everyone here in a similar situation with their meter.
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#37 Reply
Posted by
giosif
on 23 Aug, 2019 23:14
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Just a quick update on this: I can confirm that the shorts on caps C46, C55 and C92 are NOT indicative of a problem.
My resurrected 289 measures short across those caps, yet it works just fine.
Moreover, I've recently got my hands on another working 289 (this one is the newer revision, with the coin-cell battery instead of the supercap) and the shorts across these caps is also present.
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Can you tell me how you do it..?
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#39 Reply
Posted by
giosif
on 02 Sep, 2020 18:14
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Amm... Not sure if the question is for me and, if it is, what it is about (i.e. how I did what?).
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Unless mistaken Fluke never issued a recall for the supercap issue, my 189 worked fine with no supercap while being ordered
Only time feature / clock did not work until settled, the clock will start a zero ..... no problem ?
No but if you mentioned to your AD that the DMM would have an abnormal consumption of batteries when turned off, they would ask you to send it back, even if you weren't the original owner (happen with me with my 289 that I am the original owner, and with one 187 that was bought used from a colleague).
At least in Portugal, they would service, exchange the cap/PCB for one fixed and even calibrate free of charge. From what I remember, mine doesn't now have consumption of battery but at the same time it doesn't keep the time when the batteries are removed (can't be sure, I don't have it with me currently to test).
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the 289 first revisions had a super capacitor who gave some problems, normally it should keep the clock ticking for a while ... the latest revisions had a coin cell if i recall correctly, you could have a bigger current cosumption because of this
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Never noted or even tested to be sincere after being service. I realised that the batteries were not being eaten at a fast rate as before - When it had the faulty Cap it was at a rate from full to half battery indicator in less than 2 weeks turned off.
Back in 2017 I tried with batteries a full 4 months in standby, no depletion of battery (I always take out the batteries if I use Alkalines instead of Eneloops).
Also worth mention that my 289DMM is one of the first ones to be manufactured, lower 200s serial number.
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It's ALIVE !!!
What I've done since my previous post was to test the IR connectivity (thankfully, I had the IR-USB cable for it).
And the connection worked:
- I issued the "ID" command and got the correct response back
- I started issuing some "QM" commands in various settings of the rotary switch and the meter displayed at least the correct function
- Suspecting the meter might have some custom configuration settings from the previous owner, I went ahead and issued a "RMP" to reset to factory defaults.
And, surprise-surprise, the meter beeped when I turned it off.
So, of course, I then tested the input jack detection and I got the alert when the lead was inserted in the wrong jack.
Also, continuity testing is working now as well.
- Finally, I tested DCV readings from my power supply and they are pretty much spot on.
So, thanks to everyone here, it seems I've now got myself a meter in a fairly decent state (except for the LCD, of course).
Thank you all for your help!
Now off to finding a replacement LCD for it...
how you did this what i mean.. i new in this forum.. i want to ask you but i dont know how directly ask you, i have same situation as you, my fluke 287 blinking, how yo do it with usb ir.. pls help me..
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#44 Reply
Posted by
giosif
on 07 Sep, 2020 20:07
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Hi,
Not sure I am reading your post correctly, but I think you are looking to fix the meter using the IR-USB cable.
If this is indeed what you intend to do, it is not how I fixed my meter and the part you are quoting was mainly to do with the fact I did not have a working screen for the meter (in addition to the original issue).
The way I fixed the meter was by reflowing the main IC (U26) - i.e. I used a hot-air station and flux to heat the IC and the board area around it until the IC would move ever so slightly (and then spring back on its own), when pushed (very gently) to the side with tweezers.
At that point, I let the board and IC cool down, put the meter back together and tried to power it on (using a bench power supply).
And, this time, it looked like the meter was powering on properly (i.e. the led would turn solid green for a few seconds, then turn off, while the meter was still drawing a few miliamps from the power supply - indicating it was not turning itself off).
Hope this helps...
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As you discusion you try test that any component short.. i have same situation to.. my meter have short component to i try to check capacitor short and nothing capacitor short.. and my fluke gone blinking and it cant be turn off only with with cut off the baterry, i want to test to do like you are doing to..
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#46 Reply
Posted by
nixxon
on 23 Sep, 2020 19:05
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I just bricked my Fluke 289 that previously "only" had two issues with a non working LCD circuit and resistance measuring.
After connecting my oscilloscope ground to battery negative and probing the LCD driver pins one by one (the breakout board pins), the 289 entered the well known bricked mode (5 flashes of the power button). I have searched the internet, but it seems that nobody has figured out how to exit this 5 flashes of death mode.
It is a shame, because everything (other than the screen and resistance measuring) was working perfectly before I messed with the LCD driver pins. I could do regular logging and communicate via the IR-USB connection.
Has anyone figured out how to exit the 5 flashes bricking mode?
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the 289 first revisions had a super capacitor who gave some problems, normally it should keep the clock ticking for a while ... the latest revisions had a coin cell if i recall correctly, you could have a bigger current cosumption because of this
to whom it may concern: did a supercap replacement on my 289 (ser. 22160xxx) long time ago.
current consumption is:
OFF : 25 µA
ON : 25 mA
Bright_1: 36 mA
Bright_2: 55 mA
HTH
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#48 Reply
Posted by
BravoV
on 25 Sep, 2020 07:09
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the 289 first revisions had a super capacitor who gave some problems, normally it should keep the clock ticking for a while ... the latest revisions had a coin cell if i recall correctly, you could have a bigger current cosumption because of this
to whom it may concern: did a supercap replacement on my 289 (ser. 22160xxx) long time ago.
current consumption is:
OFF : 25 µA
ON : 25 mA
Bright_1: 36 mA
Bright_2: 55 mA
HTH
Thanks
, btw how did you measure the cap's current ?
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self-adhesive copper foil and kapton make for an excellent current spy.
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