Author Topic: Fluke 289 not quite sorted.  (Read 28950 times)

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Offline purpose

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Fluke 289 not quite sorted.
« on: November 16, 2017, 10:43:24 pm »
Evening all.
I just took a punt on a faulty ebay 289.
Fixing what was most obvious (a broken battery connector) bore no fruit, but power was getting to it and it was drawing a steady 25mA.
There is no screen action (not booting) and I'm unable to turn it off without removing the battery, or turning off the power supply.
Nothing on the pcb appears to be getting hot and the lcd connector is properly seated.
Bit of supercap crud, but showing 3.2V when powered.
Anything sound familiar?

Any and all help warmly welcomed.

Peter

« Last Edit: November 18, 2017, 11:26:38 pm by purpose »
 

Offline retiredcaps

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Re: Fluke 289 woes.
« Reply #1 on: November 16, 2017, 11:46:41 pm »
Q1). Is there any alkaline leaked battery residue/corrosion on the pcb or battery terminals?

Q2). Maybe check Y1 and Y2 to make sure the clock is running.

Q3) Check to see if the MSP430 is getting vcc?

Q4) You could trying removing the supercap to see if that allows the 289 to boot?

I don't have a 28x so I don't know if 25mA is normal or not.  I do know the 28x battery life is supposed to be a minimum of 100 hours.  So if your alkaline are 2500mAH, then 25mA draw sounds correct.
 
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Offline purpose

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Re: Fluke 289 woes.
« Reply #2 on: November 17, 2017, 12:27:28 am »
Evening Sir.
A1 There is not. Pcb is in good order, apart from the previous owner scratching up the battery pads, which are now covered in solder and getting power from a psu.
A2 Both clocks running, but wandering.
A3 Pin 1 showing -0.8V... which doesn't sound right. Those pins are miniscule.
A4 I could, but have no hot air. I could butcher it though... needs replacing anyway. I'll report back on that one.

Cheers
Peter


 

Offline purpose

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Re: Fluke 289 woes.
« Reply #3 on: November 17, 2017, 12:33:35 am »
All those lovely test points and no list of pokery... sigh.
 

Offline purpose

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Re: Fluke 289 woes.
« Reply #4 on: November 17, 2017, 12:52:46 am »
Lifted the supercap... no joy.
 

Offline retiredcaps

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Re: Fluke 289 woes.
« Reply #5 on: November 17, 2017, 02:57:16 am »
A2 Both clocks running, but wandering.
What frequency is it running at or what range?

Quote
A3 Pin 1 showing -0.8V... which doesn't sound right. Those pins are miniscule.
This a picture of a Fluke 287 from another eevblog post, but I suspect the 289 will be close or identical, but it looks like C42 connects to pin 1 of MSP 430.  You can measure the vcc at the + terminal of C42.
 

Offline retiredcaps

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Re: Fluke 289 woes.
« Reply #6 on: November 17, 2017, 03:00:13 am »
All those lovely test points and no list of pokery... sigh.
I don't have a 28x, but maybe someone with one can kindly provide voltage readings at all these TPs for reference.  That might help narrow down which section is wrong.

Past Fluke service manuals had documented readings for each TP and a suggestions on what might be wrong if that reading was missing.

Those service manuals now are no longer made available to the general public for modern generation meters.
 

Offline purp

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Re: Fluke 289 woes.
« Reply #7 on: November 17, 2017, 11:43:38 am »
Morning,
Second moniker, as I faffed something last night.

The MSP430... I was checking one of the other pin 1s..!! Pushing 60, my eyesight is no longer like a hawk. 3.4V is what my scope is now seeing at C42.
Frequencies are Y1 32.77k and Y2 32.76k and solid.

Cheers
Peter


 

Offline purp

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Re: Fluke 289 woes.
« Reply #8 on: November 17, 2017, 12:40:29 pm »
Would you Adam and Eve it... Turned it off and on again and it sprung into life..!! Turned itself off after a minute, but some progress.
 

Offline mzacharias

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Re: Fluke 289 woes.
« Reply #9 on: November 17, 2017, 11:36:11 pm »
25 mA quiescent current is excessive - something should be getting hot, perhaps after a minute or two.
 
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Offline purp

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Re: Fluke 289 woes.
« Reply #10 on: November 18, 2017, 12:02:43 am »
I believe you to be correct sir, but I can't find the culprit with the back of my finger.
When it works, it's pulling 18-20mA, but then shuts down after a minute or so, usually when menu hopping.
I'll get to the bottom of it if it kills you.
 

Offline purp

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Re: Fluke 289 woes.
« Reply #11 on: November 18, 2017, 09:15:12 am »
On one of the rare occasions that the meter was functional, I managed to do a 'reset to factory default' and it's been on for an hour now.
Looks like this may have been a software problem.
Anyway, I'm delighted to have a meter long lusted after.
The only downside is that it makes my hands look small..!!

Thanks for chiming in gents.

peter
 

Offline retiredcaps

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Re: Fluke 289 woes.
« Reply #12 on: November 18, 2017, 08:07:51 pm »
On one of the rare occasions that the meter was functional, I managed to do a 'reset to factory default' and it's been on for an hour now.
I was going to suggest that when I saw your post about it shutting down after menu hopping.  I'm glad you got it all sorted out.

I think 1.16 is the latest firmware for the 28x?  See

http://www.fluke.com/fluke/r0en/Support/Software/DMMUpgrade.htm
 

Offline purpose

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Re: Fluke 289 not quite sorted.
« Reply #13 on: November 18, 2017, 11:28:14 pm »
I spoke too soon.
It was working flawlessly for around eight hours and then died on me.
My work is still ahead.

I'll not attempt flashing the beast until it's 100% stable.

peter
 

Offline Samogon

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Re: Fluke 289 not quite sorted.
« Reply #14 on: November 19, 2017, 12:09:57 am »
 Cold joint?
 

Offline purpose

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Re: Fluke 289 not quite sorted.
« Reply #15 on: November 19, 2017, 12:37:20 am »
No thanks... I just had one.

I've got a hot air gun on order and will likely go over the old girl.
Failing that, I see a professional needed.
 

Offline Yakuzza

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Re: Fluke 289 not quite sorted.
« Reply #16 on: November 26, 2017, 12:40:33 pm »
Hi all.
This is my firts post here at the forum. I did some reasearch and this thread seems to be the closest to what I’m experiencing. Here is my story.

Recently I found a broken Fluke 289 in my company and decided to take it apart and check if I can repair it. Basically, after pressing the power button it lids up for couple of seconds and turns off. Nothing on the LCD, no other action.

Just for the record, I don’t have education in electronics, just some minor hobby projects (like trying to repair a multimeter :) )

I’ve opened it and examined the PCB, but in general it was in a very good shape. No visually burned elements etc., except for the coroded supercap. I’ve found the thread on this forum about it and I thought that might be a reason for it not to work. I’ve order a new one and replace it, but nothing changed.

Here is what I measured:
1. I push the power button and the meter starts to draw current up to around 45mA in the first 4-5 seconds.
2. There is a very short blink of the power light after maybe 1-2 seconds form powering it up.
3. The power light turns off and the current draw goes down to around 25mA. There is nothing on the LCD. The current draw is steady.
4. I have to push the power button again to see that the current draw is dropping to 130 microA, but dropping slowly, which I assume is due to charging the new supercap.

In addition, which I didn’t mentioned this at the beginning, there was a bit of greenish dried fluid marks in on PCB close to Amper input (between the two left input jacks) and similar thing on the top corner of the LCD, close to the soldered wires. I’ve clean it but found no source.

The meter is probably quite old, but I don’t know how to check that. I have only the unit, no probes, no box etc. There is a date on the board: 2005.

Here are some questions to you guys:
1. Just to check if there is a warranty option, where can I find the production date, serial number, and other info needed to fill the online form for requesting repair by Fluke. I’ve read that it might have 10 years of warranty, right? Note - LCD doesn’t work.
2. Assuming the warranty is not an option, what else can I check?
3. Does the power light in an operational meter behaves in this way, that is lids up for couple of seconds and then turns off? The steady 25mA might be a sign, that everything except the LCD is fine, right?
4. How can I check the LCD itself?
5. Anybody have some readings on the test points, so I can compare them with my unit?
6. This might a silly question, but how can I attache voltage to PCB? There are those two small copper areas in the middle of the board and small holes right next to it. Are there any special probes cable that you stick the board on them or what?

I can upload pictures of any interesting parts of the multimeter.

I would really appreciate any help and tips you can give me.
Thank you all and have a nice day!
 

Offline Muttley Snickers

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Re: Fluke 289 not quite sorted.
« Reply #17 on: November 26, 2017, 12:55:53 pm »
You can forget about the warranty altogether unless you are the original purchaser and can prove that it was bought from a local authorised Fluke agent. Make sure you are using a good set of new batteries, which batteries are you currently using to power the meter ?.
 

Offline Yakuzza

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Re: Fluke 289 not quite sorted.
« Reply #18 on: November 26, 2017, 03:50:14 pm »
I’m using Alkaline Energizers with measured 1,47V per cell, with total of 8,82V.

In addition I just checked the following:
 :-/O 5. On the constant voltage setting the meter is drawing 19,6mA. I started to push other buttons to see if I get other readings and when I pressed the light button the LCD starter to glow nicely with current draw increased to 33mA. After pressing the light button again the intensity of backlight goes up and the current draw also up to 53mA.
Still, there is nothing on the LCD.
 

Offline saturation

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Re: Fluke 289 not quite sorted.
« Reply #19 on: November 26, 2017, 04:42:20 pm »
Fluke will only warrant defects in factory parts or workmanship, not damage from use.  If you send it in, assuming you find serial number etc., they can reject the claim if they find it damaged from use, also you need to have bought it through an authorized reseller.  However, the cost for a repair maybe less than the cost of a new unit since its cheaper to do a board swap and a cal thereafter.

If the unit refuses to boot and the input jacks appear contaminated make sure there are no shorts on the board, or any liquid residue.  If it still won't boot, its likely toast.

You can download the Calibration manual and follow the troubleshooting procedures, but in all instances, the unit first boots before a test can be run.

The simple first thing to troubleshoot a Fluke DMM if you still choose to proceed is examine the inputs carefully for damage, and then desolder the input protection.  It cannot reliably be troubleshooted in circuit.  This section takes the brunt of most injury during an input fault.  If a fault made it past input protection, the subcircuits are more delicate and it can damage quite a bit. 

Good luck!
Best Wishes,

 Saturation
 

Offline Yakuzza

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Re: Fluke 289 not quite sorted.
« Reply #20 on: November 28, 2017, 12:37:45 pm »
@saturation
Do you mean to desolder input protection and check it piece by piece?
Assuming the input protection is fine, what else can I check and how?
If the input protection is faulty, does that mean that the board might be fried as well, or should the input protection actually protect the further elements?

I will be updating this question list from now on.
Here is a summary of my questions (slightly rephrased) and with some answers:

Q1. Just to check if there is a warranty option, where can I find the production date, serial number, and other info needed to fill the online form for requesting repair by Fluke. I’ve read that it might have 10 years of warranty, right? Note - LCD doesn’t work.

Ans: Since I’m not the original owner and I don’t have any papers to even show when and where the meter was bought, the conclusion is that the warranty is off the table.
-Q1 closed-


Q2. Assuming the warranty is not an option, what else can I check?

Q3. Does the power light in an operational meter behaves in this way, that is lids up for couple of seconds and then turns off?

Ans: I’ve just found out that according to Calibration Manual, in the “Power LED test” section: “... power button [should] lights for approximately 4 seconds, and then extinguishes”, which is what I observe in my unit. That is okay than.
-Q3 closed-


Q4. The steady 25mA current draw might be a sign, that everything except the LCD is fine, right?

Q5. How can I check the LCD itself?
Can I assume that pin 1 is ground and pin 2 is VCC, and check if get readings on the board, after disconnecting the LCD?

Here are some data I found in the Calibration Manual:
dot matrix LCD, DS1,
LCD MODULE,289,320X240,FSTN,3.5 MONO GRAPHIC,TRANSFLCTV,WHITE LED,0.22MM PITCH, Part number 2734828.

Q6: Anybody have some readings on the test points, so I can compare them with my unit?

Q7: This might be a silly question, but how can I attache voltage to PCB? There are those two small copper areas in the middle of the board and small holes right next to it. Are there any special probes cable that you stick the board on them or what?

Ans: According to Calibration Manual: “TP8 and TP10 can also be used to apply power to the PCA.” And since these two points are on the side of the board I can use crocodile connectors or something similar.
-Q7 closed-
 

Offline purpose

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Re: Fluke 289 not quite sorted.
« Reply #21 on: November 28, 2017, 08:57:26 pm »
Yakuzza,
I'll be borrowing a working 289, so I'll get some readings up soonish.
Trouble is knowing from where to where one measures.

I was onto Fluke UK, asking about their 'fixed price repair' and was told £271 plus this and that.
I'll not be sending it to them.

peter
 

Offline Yakuzza

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Re: Fluke 289 not quite sorted.
« Reply #22 on: November 28, 2017, 09:13:14 pm »
@purpose
Hi. I’ve assumed you managed to repair your unit, but I see you still haven’t fix the issue. Well, about the readings in test points I thought to measure in respect to ground, but maybe that is not a correct approach. Anybody?

I actually just did some readings on the LCD connector and few test pins, and then I realized that it doesn’t make sense to compare it with other unit’s readings. There is no Service Manual available for this model (as far as I tried to find one), so even if we identify differences in readings there is no reference to say what does that mean and what is broken. Don’t you agree?

Tomorrow I will try to grab a friend which owns a CAT mobile phone with infrared camera, so maybe I can have a look at the board and see if there is something suspiciously warmer than other.

The fact is that I don’t want to spend hundreds of pounds for repair of an old unit (with unknown history of usage, without all the accessories and even test leads). I will do few attempts and check what I can, with some advices from you guys, and if it does not help I will just ditch it.

I can share my readings in test points if you like, maybe we can see a pattern anyway  8)

Cheers,
Mike
 

Offline purpose

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Re: Fluke 289 not quite sorted.
« Reply #23 on: November 28, 2017, 09:55:27 pm »
Yep... it's back to NFG.
I'll measure all points on the working 289 relative to the common input for starters and post the results.
I invested in a cheap FLIR TG165, in the hope of seeing something the back of my finger is missing.

peter
 

Offline purpose

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Re: Fluke 289 not quite sorted.
« Reply #24 on: November 29, 2017, 10:43:04 pm »
I've got most readings from a good one... enough to know that my -2.5v rail is kaput.
All measurements taken relative to COM input, switch at VDC and 9V to the battery pads.

TP    BAD    GOOD
1    -0.81   -2.49
2     2.26    0.61
3    -0.13    2.49
4     2.26    0.61
5     2.25    0.61
6     2.24    0.61
7    -0.81   -2.49
8     8.23    6.53
9     1.16    1.11
10  -0.81   -2.49
11   0.23    0.46
12   -0.81   -2.49
13   2.22   0.438
14   -0.81   -2.49
15   2.13   0.438
16   2.11   0.437
17   2.26   0.609
18   0.98   0.68
19   2.13   0.43
20   2.13   0.43
21   2.13   0.43
22   2.13   0.43
23   2.13   0.43

28   -0.81   -2.49

30   -0.81   -2.49
31   -0.81   -2.49
32    2.26    0.61
33    2.26    0.61
 
U20, which I assume to be some sort of pwm, is chuffing along on one side at 293kHz and other side at 143kHz. Both at 97/98% duty.  How pertinent that may be, only one of you can tell me.

BTW... My new TG found the 10mA hungry component, but removing it just brought the draw to the normal 19mA and did nothing for the rails.

peter


« Last Edit: November 29, 2017, 11:27:49 pm by purpose »
 


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