vB Easy Archive - How do I replace Microphone on V3

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How do I replace Microphone on V3
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Posted by: nvrminds

I recently washed my phone (and spun it at 1100 rmps - GO LG front washer - and made it smell good with a little Downy). The battery died but a replacement has worked. It looks like the only casualty is my microphone. I can hear people just fine but they cannot hear me. I have found a replacement mic but as I inspect the board, I am not sure how to remove the old mic. It is sheltered by a silver "can" that appears to be fixed (glued?) to the board. What is the best method for removing the old mic? Thanks for anyone's help on this. Have a great day

Posted by: Black Cat

The microphone is a board level soldered componenet located underneath shielding.

Since the shields and mic are connected with a lead free solder, you will need some specialized equipment to repair this.

It can be done, we have done plenty, but it takes some practice.

Posted by: SimpleKindaMan

Quote:

Originally Posted by Black Cat

Since the shields and mic are connected with a lead free solder, you will need some specialized equipment to repair this.

What specialized equipment is that? I've been using the same soldering iron and heat gun since before the lead free revolution. Pb free just flows a little differently and has a higher melting point.

Replacing the mic will work provided that is all that is damaged. If the phone was submerged with connected current for that long, you're probably looking at a lot more than a mic problem.

Posted by: Black Cat

You can do them with the old fashioned stuff, but the quality of the soldered joints suffer. Given that the solder lands are totally hidden and the reflow temp is several hundred degrees higher than that of leaded solder, it is very difficult to properly set the mic and there is a very high risk of heat damage to the board. The failure rate on this type of repair is high when the correct tools are not used.

We have invested in a high end pre heater, board vises and hot air soldering stations. Not only is the failure rate very small, but the repair time is a fraction of what it would be otherwise.

I would also add teh mixing lead and lead free solders DO affect the joint quality as well as the conductive properties of the solder. It is very important to keep cross contamination from happening.

We have multiple solder stations, solder wicks, solder, tips, flux, etc.

Posted by: Mr.Conviviality

Quote:

Originally Posted by Black Cat

You can do them with the old fashioned stuff, but the quality of the soldered joints suffer. Given that the solder lands are totally hidden and the reflow temp is several hundred degrees higher than that of leaded solder, it is very difficult to properly set the mic and there is a very high risk of heat damage to the board. The failure rate on this type of repair is high when the correct tools are not used.

We have invested in a high end pre heater, board vises and hot air soldering stations. Not only is the failure rate very small, but the repair time is a fraction of what it would be otherwise.

I would also add teh mixing lead and lead free solders DO affect the joint quality as well as the conductive properties of the solder. It is very important to keep cross contamination from happening.

We have multiple solder stations, solder wicks, solder, tips, flux, etc.

What's a reasonable charge for such a repair?
I have heard prices from relatively cheap to disgustingly expensive.

It appears as though you know the procedure well enough to comment- and I'm lookin' forward to it.

TIA,
Mr.Conviviality

Posted by: Black Cat

We charge $75. Keep in mind we are set up for this kind of work and repairs are 90% of our business. The mic will also be replaced with a new part straight from Motorola - no scavenged parts.

The hard part in this case, knowing whether the mic is the actual issue. If the liquid damage blew the mic, the replacement solves the issue. If it blew and audio chip or circuit, the mic probably will not help.

Posted by: nvrminds

Quote:

Originally Posted by Black Cat

We charge $75. Keep in mind we are set up for this kind of work and repairs are 90% of our business. The mic will also be replaced with a new part straight from Motorola - no scavenged parts.

The hard part in this case, knowing whether the mic is the actual issue. If the liquid damage blew the mic, the replacement solves the issue. If it blew and audio chip or circuit, the mic probably will not help.

1)What other indicators are there to a blown chip or circuit?

I do have a background in avionics repair but I do not have access to the stations that I used in the Coast Guard.

2)Is the shield connected to the board with solder? Would that shield be removed then by heating up the edges and pulling it away?

3)It also sounds like the mic is "attached" to the shield. Is that accurate?

4) it sounds like the mic will need to be soldered in. Or does it "slide" into place under the shield?

5) would a blue tooth be a trouble shooting tool for the chip / circuit blowing?

Thanks for your earlier reply and it came very quick. I appreciate your information especially since it sounds like this is your lively hood. Honestly, this comes at a bad time (no job) and sinking money into it is not an option. I have seen the part for the mic for about $10 online and I was hopeful that I might be able to do the repair myself (considering my previous work). Thanks.

Posted by: Black Cat

1)What other indicators are there to a blown chip or circuit?

You would need to test each chip and the traces for continuity

I do have a background in avionics repair but I do not have access to the stations that I used in the Coast Guard.

2)Is the shield connected to the board with solder? Would that shield be removed then by heating up the edges and pulling it away?

The shield is lead free soldered, the process is to heat nd remove.

3)It also sounds like the mic is "attached" to the shield. Is that accurate?

No. The mic floats over 4 contact patches.
4) it sounds like the mic will need to be soldered in. Or does it "slide" into place under the shield?

The mic is soldered down and the solder joints are not visible so a soldering iron will not work. You need to get the solder hot enough (without damaging the board or the new mic since lead free melting points and reflow qualtiy require quite a bit of heat) to remove the old mic and then properly position and seat the new mic.

5) would a blue tooth be a trouble shooting tool for the chip / circuit blowing?

Not sure how.

It is easy to do once the skill set is there. The learning curve is the issue. We do quite a few board level repairs from chipsets to data connectors (like the charger port). But the lead free stuff and the shields and the floated solder connections took some time. We still melt the ocassional mic.

Posted by: Tyler Durden

I am actually glad this topic was brought up for the mic. I always tell my customers that when their V3's go into water, there's a 50/50 chance that the mic won't work. I can take them off the motherboard just fine and have the original Motorola mic parts as well. My question is (and since it seems you know more about this Black Cat, this is geared towards you) how do I solder the mic on if it's original soldering job is located underneath the mic and not around it like the sheild is?

Posted by: Black Cat

Tyler,

We have highly specialized SMD and board rework equipment in our facility. Our setup is similar to what might be found in the manufacturer's own shop. This repair does not involve a soldering iron at any point.

As a note, I do not replace mics on wet V3s. given the failure rate, I do not have the time to replace mics and not be paid (most people won't pay our price if the repair does not work).

Posted by: mds33200

I have no problem installing the new mic, I just have a hard time removing the old one without damaging the pad or the board. I use liquid solder and have had no problems with that method. any advice to remove the old one?

Posted by: cingularv551

you can grind away the microphone using a dremel with the appropriate attachment on it.

Quote:

Originally Posted by mds33200

I have no problem installing the new mic, I just have a hard time removing the old one without damaging the pad or the board. I use liquid solder and have had no problems with that method. any advice to remove the old one?