T4D #88 - Fluke multimeters with leaking / corroded surface mount supercap

[Davel81]

Ok guys..
I took apart my meter again.
17:16pm removed batteries
left them out for an hour
replaced batteries at 18:17pm
meter time message said i had to update the clock
it was showing a time of 17:17.15pm
so the cap isn't holding a charge at all

i put new batteries in meter 9.75V dc off load using a fluke 117 dmm
used links from battery pack to 289 meters pcb.
the cap was measuring 1.190V dc before i connected battery
with battery connected  9.74V dc on load
the cap charged to 3.142V dc instantly and topped at 3.162V dc
removed supply voltage and cap dropped to 1.237 over about 15 seconds and continued to drop at a much slower rate.
Metered cap using the 117 dmm set on capacitance and the  display changed from 0 nF (leads open circuit) to ol micro farads.
id safely say the cap has failed

[SeanB]

Dead, died and the only reason it is still there is that it is soldered to the perch. It is pining for the fjords. It is an eX-capacitor.

Probably the internal impedance is rather higher than the maximum specced 4k of the datasheet. If it was mine i would put in a 1F 5V5 supercap, plenty enough room in there for it, though you might have to use 2 short leads to connect it for some of the larger units and a small foam tape hold down to stop rattling.

[Davel81]

Ya if it were only that simple
put the meter back together and now its dead. i have a blue screen on the meter and nothhing else it wont even turn off unless i pull the battery pack 

[SeanB]

Open, short the cap terminals for around a minute, short the battery terminals and try again. Likely the internal micro was confused by trying to measure the capacitance, that can only be done with a controlled constant charge and discharge to get the slope of the line or by coulomb counting from fully discharged ( takes a long time) to charged.

[Davel81]

thanks i've tried that a few times but still the same

[SeanB]

At least you still have a RMA coming. Leave the batteries out overnight.

[Davel81]

Ya ill send it back now anyway. not much choice. 
So checking the cap with the dmm caused this??
well on the plus side i learned that doing that is BAD  and ill never do that again!

[Davel81]

So I got my fluke 289 back the other day and it's working flawlessly, fair play to the lads in fluke service they even replaced the back cover as the battery connection was dodgy. new board put in so I won't open it as is calibration stickers and tested seal would have to be broken.

[M. AlGailani]

Hello,
I have the same problem with my 4 years old fluke 289, when I replace my batteries I lose the time setting. The super capacitor is suffering from corrosion also.

[M. AlGailani]

I decided to order the super capacitor and replace it myself, but after reading the posts, I decides to contact fluke, to see if it is possible to get a fix, and hopefully a calibration to my fluke 289. It was calibrated on Mar 3, 2008 and a fresh calibration will be nice. 

[M. AlGailani]

I called fluke service and they issued an RMA immediately. Although I am original owner, they did not ask if I am the original owner. They asked me if I had an account in fluke and I replied yes, but I could not remember my account information.
I received the RMA on May 9, 2014. Send the meter and received confirmation from fluke on May 12, 2014 that they had received my meter.
My fluke 289 was in a very good condition (like new). No scratches no dirt no sign of wear.   

[M. AlGailani]

It took some time before I got any information about the status of my fluke 289.
After 43 long waiting days (Jun 24, 2014), I received back the meter.  ;DI was indescribably happy to notice that fluke: 1. replaced the main PCB, 2.replaced the LCD, 3.replaced the battery door, and calibrated the multimeter.

   

   

[M. AlGailani]

The condition of my 289 was very good. I do not know why fluke replaced the battery door or the LCD, but I am very happy because my old board had ID: 1 and the new board had an ID: 3. I am not sure what are the difference between board ID: 1 and ID: 3, can anybody post a photo or provide any information about the differences?
In the beginning, I was hoping for a simple repair and calibration, what I got is almost new meter. Every part is new except for case that contain the serial No.

    

[SeanB]

Probably they replaced the battery door because they had done an upgraded mould to reduce breakage in the field. Main board and LCD probably came as a pretested and prebuilt unit, so faster in the service centre to just place the whole module if doing a board swap, as you do not then risk breaking tabs and the time is shorter.

[M. AlGailani]

SeanB,
Yes you are probably right.
What are the differences between board ID1 and board ID3?

Thanks.