Tesoro 11" widescan µMax coil opened up, falsing problem:

[sido]

Hi kt315, yes i would say also that the coil is un-repairable due to epoxy glue and the difficult nature of removing the coil from housing and without damaging further the coil winding lacquer protecting coating on copper wire with such epoxy remover as listed above.

Interesting epoxy remover though kt315. I worked repairing BGA components for ten years with Nokia mobile phones. Thankfully no clear epoxy glue was needed to be removed on such delicate components. Though they did have a similar soft black epoxy looking putty on some earlier BGA components in 2000, but the process was scrapped for easier removal and repair.

Never seen this product, but looks interesting.

Below on pic is just a few observations of mine.

Cheers Sido

[kt315]

sido, best suggestion is to sell the coil as-is at ebay and forget about. the case is deadly burnt because there is not any progress movement.

http://www.ebay.com/itm/INSAT-BGA-EP...item4d01789e95

Insat BGA Epoxy Glue Remover
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[Pinpoint]

Thanks Sido, I'll try that, I've actually striped back some of the foam, the shielding wire is a bit sus in one area, just looks a bit messy but I'll try squeezing it in that area.

[sido]

Hi Pinpointer.

After thinking about it, i may have a suggestion that may help you in isolating the problematic area for you.

Either your problem is as Kt315 suggests that the coil lead entering the coil or maybe the upper side ground wire similar to the loose wire shown on your pic is loose. Try this.......

Take unit out side on soil/grass free of metallic objects. Get someone to help you to hold the detector as if there detecting that area. Get the person to hold the detector still, flat on the ground. Once you have the detector settings adjusted, GB etc, try this....

Now squeeze, hold or apply pressure with a couple of fingers to the coil area you think maybe faulting. You might need to secure and tape the loose wire in the picture under the coil so it does not move. Then while applying pressure, tap the coil gently with a non metallic object. Keep rotating, holding and trying different positions on the coil with tapping off course.

If squeezing and applying pressure to the top half of the coil eliminates the falsing when tapped, then visually observe the position. If it happens to be the opposite side of the cable entering the coil, then the problem area maybe the faraday shielding wire may have come loose from graphite material on the top coil housing.

If falsing is still occurring then as Kt315 suggested.

Note also: if the wire is broken though and some internal moisture has built up between wire and graphite material then the above method will be useless, due to a higher resistance, Worth a try though.

Cheers Sido

[Pinpoint]

I'll probably end up putting it back together.

[kt315]

it's real problem you have not the hands. i see one same picture everyday like Groundhog Day movie playlist. hey! you there! do anything man! take epoxy resin remover, wash it out!
silent, new day will begin again from f-ng wakening because that is Groundhog Day!

[Pinpoint]

The more I look into it, the more I think post #5 is the issue, I think you are right kt315. I know this sounds stubborn, but is there any way to push the coil cable through the housing?

[Pinpoint]

have you an electronics service around? there are always nuts'n'bolts guys with LC meter wishing help you.

You don't want to know what happened last time I took something to an electronics service near my area. Thankfully Sido fixed it.

Though yes, it would be good if I could take it to an electronics guy without having to send it somewhere. I'm still thinking.

[kt315]

Yeah, I won't be able to test the inductance in that case, but I'm keen on removing part of the foam, I'm sure I know the source of the problem.

have you an electronics service around? there are always nuts'n'bolts guys with LC meter wishing help you.

[Pinpoint]

Yeah, I won't be able to test the inductance in that case, but I'm keen on removing part of the foam, I'm sure I know the source of the problem.

[kt315]

This acetone, could it damage any part of the coil?

I don't know how to measure inductance, I have a multimeter, don't know if that will do. Looking it up now.

I mean you will not run the acetone of big dose. do by a sodden brush deleting gradually. you need in LC meter, not ordinary cheap multimeter.

[Pinpoint]

pinpoint, can you measure inductivity of coil? by acetone you can delete the foam. get it from your moom, they use liquid for nail varnish deleting, it contains acetone.

This acetone, could it damage any part of the coil?

I don't know how to measure inductance, I have a multimeter, don't know if that will do. Looking it up now.

[kt315]

pinpoint, can you measure inductivity of coil? by acetone you can delete the foam. get it from your moom, they use liquid for nail varnish deleting, it contains acetone.

[Pinpoint]

Upon further inspection, tapping around the bottom of the coil, the falsing mainly seems to come from a specific area, I've marked it in red. The area marked in blue is where the coil cable goes into the housing:


Can this be fixed? Should I try to get to the problem by removing the foam around the area marked red?

[Pinpoint]

Solder the wire to a short spring (10mm to 15mm long) of about 15mm diameter. When you refit the bottom half of the coil shell, the spring will make electrical contact. Garrett Crossfire coils use an electrostatic sheet either side of the coils, and this is how they get a good connection.

Thanks for advice , but that didn't help.