Service manual Fluke 179 - Page 1
Forum section: electronics / repair

author: andy_speedy
author_rank: Newbie
timestamp: January 12, 2017, 02:00:26 pm
content: Hello,I have a Fluke 179 and looking for a service manual.The meter is not working.Battery has already been changed.Can someone help me?

author: retiredcaps
author_rank: Super Contributor
timestamp: January 12, 2017, 06:22:40 pm
content: You won't find any public service manuals with schematics, bill of materials, etc for any modern/current handheld Fluke multimeter.If you want help, state what is not working and provide clear focused pictures of your meter pcb (both sides).The more info you can give us, the more we can possibly help you. "Not working" can mean a lot of things.

author: andy_speedy
author_rank: Newbie
timestamp: January 13, 2017, 10:05:00 am
content: Hello here still a few pictures from the circuit board.It does not do anything, either a display or turn on the lighting.

author: jeroen79
author_rank: Frequent Contributor
timestamp: January 13, 2017, 11:10:38 am
content: Quote from: andy_speedy on January 13, 2017, 10:05:00 amIs that all it does not do?Can you make the continuity checker beep? On my 179 the buttons also beep.Do the resistance, continuity and diode modes produce current from the VoltOhm jack to the Common jack?You could start by checking if the various ICs get power from the battery. You'll have to figure out which pins go to the battery though.Can you measure some activity on the pads going to the LCD?Could the zebrastrips going to the LCD or the LCD be faulty?

author: andy_speedy
author_rank: Newbie
timestamp: January 13, 2017, 11:59:35 am
content: The lcd is a whole new one.From time to time you can see a display on the display.If you turn it on, there is a very quiet buzzing from the buzzer.No change when pressing the buttons.Where on the IC can I measure what?

author: jeroen79
author_rank: Frequent Contributor
timestamp: January 13, 2017, 12:28:08 pm
content: I don't know the pinout of the ICs. But you can follow the traces from the battery and see where they go.Does the display show a better or more consistent picture if you gently press it a bit harder against the PCB and zebrastrips?What about the other functionality I mentioned?

author: ModemHead
author_rank: Frequent Contributor
timestamp: January 13, 2017, 12:57:32 pm
content: jeroen79 asks good questions. In addition, measure the current draw from the battery. If it is significantly over or under about a milliamp or two, it could indicate power problems. Also, examine the board carefully with magnification. I have often found small amounts ofcorrosionwith accompanying copper erosion in those Fluke models, even if the inside is otherwise relatively clean.

author: andy_speedy
author_rank: Newbie
timestamp: January 13, 2017, 01:11:54 pm
content: I measure at the battery about 52mA current consumption.

author: jeroen79
author_rank: Frequent Contributor
timestamp: January 13, 2017, 04:30:32 pm
content: That is quite high, mine does 2-3mA, 5 when it is sourcing for diode/ohm/continuity.Is anything feeling warmer than the rest?

author: retiredcaps
author_rank: Super Contributor
timestamp: January 13, 2017, 06:20:31 pm
content: Quote from: andy_speedy on January 13, 2017, 01:11:54 pm52mA is about 20x more than expected. Sounds like something might be shorted to ground on the pcb or the MSP itself?This version of the 179 uses the MSP430. Datasheet is athttp://www.ti.com/lit/ds/symlink/msp430f448.pdfSome questions.Q1) Is this your meter or did you buy it from ebay "as is" with the intent of fixing it?Q2) When did this meter last work?Q3) Was this meter used to measure something very high voltage (say > 240V)?Q4) Did you lend this out to a friend?Q5) Did you buy this new from an authorized Fluke dealer?Q6) Why do you have a "new" lcd?

author: retiredcaps
author_rank: Super Contributor
timestamp: January 13, 2017, 06:23:39 pm
content: Quote from: jeroen79 on January 13, 2017, 04:30:32 pmI have a dead meter which is drawing 80mA (normal should be less than 5mA) from a 9V battery and I never found anything getting warmer by touching the components so I don't know if the OP will have any better luck than I. Maybe my fingers aren't sensitive enough?

author: carl_lab
author_rank: Frequent Contributor
timestamp: January 22, 2017, 01:14:08 pm
content: If battery idle current is much over standard I'd look for a shorted electrolytic capacitor (tantal cap...).QuoteThermal imager could help...

author: merricke
author_rank: Newbie
timestamp: April 11, 2020, 02:37:14 pm
content: Fluke 179Meter was dead, battery current 5 ma and higher at timesAfter trying to test this cap across the power line, battery current dropped to about 2 ma and the meter started working.Any idea the value of this cap?

author: retiredcaps
author_rank: Super Contributor
timestamp: April 11, 2020, 07:29:08 pm
content: Quote from: merricke on April 11, 2020, 02:37:14 pmThere is no service manual for the 179.However, the predecessor to the 179 is the 70 series III.There is a service manual for the 77 iii athttps://dam-assets.fluke.com/s3fs-public/77iii___smeng0100.pdfPerhaps the schematic may give you a clue as to what ballpark cap to use? Obviously, the 77 III schematic won't be identical to a 179, but it might be similar enough that you can deduce the cap value?BTW, there are many revisions of the 179 pcb. The revision number will be around the upper LCD area if i recall correctly.

author: merricke
author_rank: Newbie
timestamp: April 12, 2020, 02:09:41 am
content: Thanks. I don't see a direct cap across the battery but there is about 2 uf to common. That sounds about right to me.My pcb is 17X-3001 Rev 007Thanks again