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!