Fluke 179 won't tun on

[keeney123]

Re: Fluke 179 won't tun on

even If you used a high intensity light in the back and then you your USB microscope.

[tibimakai]

Re: Fluke 179 won't tun on

That was made, with a USB microscope to show the broken trace inside the PCB.
The rest won't show, because if I look through the board is all black.
Only around the selector switch, is "see through".

[stj]

Re: Fluke 179 won't tun on

he ltpz is a regulator

[keeney123]

Re: Fluke 179 won't tun on

Good effort, but this is what I expect. From the eevblog 179 teardown thread, this photo shows what is needed in terms of focus, clarity and readability. My only wish is that it is a bit higher resolution to make it easier to read some of the smaller print and that it is shot directly over top.

https://lh4.googleusercontent.com/-3...h572-no/15.JPG

So is that the IC in the Lower left corner?

[tibimakai]

Re: Fluke 179 won't tun on

That trace is broken. Via is filled with oxidation as well.

[retiredcaps]

Re: Fluke 179 won't tun on

This is the best I can touch up of the picture for you retiredcaps.

Good effort, but this is what I expect. From the eevblog 179 teardown thread, this photo shows what is needed in terms of focus, clarity and readability. My only wish is that it is a bit higher resolution to make it easier to read some of the smaller print and that it is shot directly over top.

https://lh4.googleusercontent.com/-3...h572-no/15.JPG

Here I can clearly see that PCYI is a 5V LDO made by Texas Instruments. A few more searches, I found this application report entitled "Interfacing the 3-V MSP430 to 5-V Circuits". It gives a number of suggestions on how to convert 5V down to the 3V needed by the MSP430.

https://cdn.badcaps-static.com/pdfs/...26c30b52eb.pdf

Just to the left of PCYI pin 1, is a via hole. Just to the left of the PCYI pin 5 is another via hole. Assuming both are pins are connected to their respecitve via hole, if you turn the pcb around these vias will have tracks. Tracing these tracks will show where they go.

There are also 5 other major ICs on the same side as PCYI. Get the datasheet for each IC and check to see if VCC/VDD exists. Note the min and max for each IC wrt to VCC/VDD. Some might require 5V which is why the PCYI is used and not some other LDO that drops it directly to 3V? This will also help track down possible broken traces and vias. Continuity, with a reading of less than 1 ohm, is your friend when checking the vias and tracks.

As I mentioned there are at least 3 revisions of the 179 that I know of. The earliest ones didn't even use the MSP430!

[keeney123]

Re: Fluke 179 won't tun on

Found this trace, which to me it doesn't look good.
It seems like it's going to the negative of the battery.

You could ohm that trace to find out if it is good. I would stick with what retiredcaps suggested as he knows the sequence of how the meter's circuits function. So if that trace checks out you will want to find the LDO circuit. You would trace the 9 volt supply line until you come to some regulator that lowers the voltage to the 3.6 volts. I do not know if they would do this with a IC or discrete components or a combination of the two. What ever it appears to be, it will have the 9 volts that are input-ed into it. The idea is to lower the voltage and regulate it so when the battery starts to decrease it maintains the same 3.6 volts DC

[tibimakai]

Re: Fluke 179 won't tun on

Found this trace, which to me it doesn't look good.
It seems like it's going to the negative of the battery.

[tibimakai]

Re: Fluke 179 won't tun on

It seems like, none of the ICs getting anything. At the top half part, I don't see traces through the board, it's all black.

[tibimakai]

Re: Fluke 179 won't tun on

Measuring, from pin #98 to pin #100 or from pin #99 to pin #1 I'm getting 0V.

[tibimakai]

Re: Fluke 179 won't tun on

You guys, are really awesome and I'm not.
I have some visitors(family) for a couple of weeks and I'm not able to work on this, the way I should.
Sorry about this.
I try to measure some voltages on the fly, when I have a couple of minutes.
I have other devices that require my attention, 55" Samsung LED TV, Kenwood DNN990HD nav unit, etc.

[keeney123]

Re: Fluke 179 won't tun on

This is the best I can touch up of the picture for you retiredcaps.

Tibimakai the way to take the picture would be to put a white light under it, somewhere around 5000 kelvin. Make sure the board is completely flat. If the light shines around the edges of the board use black paper from the board to the light to block this out just use scotch tape to secure the black paper. Next if your camera has a macro setting then set it to this. Get with-in 30" of the board aim down making sure the camera is completely parallel with the board. Fill up the entire camera view, however close the camera will let you get. Take pictures with flash off and then flash on. With flash off it is best to take picture outside if you can. Good luck.

[keeney123]

Re: Fluke 179 won't tun on

Finally, the right question is being asked.

The MSP430 maximum voltage is 3.6V. The Fluke 179 uses a 9V battery.

So something has to drop the voltage down into the 3V range. If the photos weren't so bad, I would be able to see the 5V LDO that you are talking about.

Thus, if the MSP430 isn't getting around 3V, check the 5V LDO. If there is no output on the 5V LDO, check the input voltage on the LDO. If there is no voltage on the input pin, check the trace from the 9V Battery positive terminal to see if the track/via is broken. If I found one broken track, there might be more.

As I said, there are no schematics, but if you photograph the 179 PCB and use a very bright source like the sun from behind, you might be able to see the traces. For example, here is my photo of the UEI DM393

http://www.eevblog.com/forum/repair/...-all-the-time/

As you can see, the picture is focused and you can see all the writing even on the smd components. You can see all the traces despite it being a multilayer board.

I have cleaned the image up some. If you magnify it I think you will be able to see the runs.

[retiredcaps]

Re: Fluke 179 won't tun on

We need to find out, how the battery voltage reaches the TI IC.

Finally, the right question is being asked.

The MSP430 maximum voltage is 3.6V. The Fluke 179 uses a 9V battery.

So something has to drop the voltage down into the 3V range. If the photos weren't so bad, I would be able to see the 5V LDO that you are talking about.

Thus, if the MSP430 isn't getting around 3V, check the 5V LDO. If there is no output on the 5V LDO, check the input voltage on the LDO. If there is no voltage on the input pin, check the trace from the 9V Battery positive terminal to see if the track/via is broken. If I found one broken track, there might be more.

As I said, there are no schematics, but if you photograph the 179 PCB and use a very bright source like the sun from behind, you might be able to see the traces. For example, here is my photo of the UEI DM393

http://www.eevblog.com/forum/repair/...-all-the-time/

As you can see, the picture is focused and you can see all the writing even on the smd components. You can see all the traces despite it being a multilayer board.

[keeney123]

Re: Fluke 179 won't tun on

So we need to go back to the information sheet on the micro controller. The supplied voltage to this chip is measured from Vcc to Vss. You can see this on page 53 of the attachment I provide previously. The range of the low supplied voltage is from 1.8 Volt to 3.6 volts maximum this can be seen on page one. If this measurement is at or above 3.6 volts maximum the chip will be damaged. So if you can try to measure this voltage. If it is too hard to measure on the processor then follow the traces back to a component that would be easier to measure. So there are two possible available supplies voltages. One pair is DVcc1 the positive and DVss1 the negative. The other pair is DVcc2 the positive and DVss2 the negative. You will need to measure across each pair. Also, you want to measure the pin under pz terminal which is the 100 pin chip not the 80 pin chip

[stj]

Re: Fluke 179 won't tun on

you need a cheaper meter for "risky" work.

most people i know have a good meter on the bench - usually fluke or UNI-T and a cheap meter for outside work incase it gets lost or damaged.

the same with the soldering iron, good one on the desk, and a cheap one for "away" work.

[tibimakai]

Re: Fluke 179 won't tun on

That is not possible to trace it, if it's the only one dmm that you have. Thanks though, for you effort.

[dj_ricoh]

Re: Fluke 179 won't tun on

Thanks for opening yours, but I don't know where should be look for yet.
Maybe somebody else can point me what else to check first.
The battery has 8.963V.
When I measure and use the the battery's negative terminal, or the COM, it seems like the result is the same.
We need to find out, how the battery voltage reaches the TI IC.

like i said mine got 5.7v

i`ll try to trace it down.

the sad part is that this is the only dmm at my home

[tibimakai]

Re: Fluke 179 won't tun on

Thanks for opening yours, but I don't know where should be look for yet.
Maybe somebody else can point me what else to check first.
The battery has 8.963V.
When I measure and use the the battery's negative terminal, or the COM, it seems like the result is the same.
We need to find out, how the battery voltage reaches the TI IC.

[dj_ricoh]

Re: Fluke 179 won't tun on

I have placed the PCB in the case and that way I have turned the switch.
I'm trying to measure DJ Ricoh's measurements, but I'm having problem seeing those small numbers.
At pin #14 I have the battery voltage of 8.963V.
At all the pins I'm measuring above 7V. That is normal?
CD4069UBE

Ill open it again check.

Tell me where to focus.