Mxt threshold?

[rockpup1]

Ok I know my machines not working right.I pretty much got scammed on my used machine deal.I put up with the problem for the end of my season.Yielded some returns including a large gold wedding band,but I did better with my big bud 220-D.

I took the machine apart.I think I found the problem.Looks like a inside pot has a bad solider connection.
I'm sure I fixed that.I tried to test but its Canada and wrong time of the year to go outside.I still think the problem is there.

I can run the threshold to zero(silent) and the more I turn up the sensitivity the worse I get a irregular static sound.I can run around 3 sensitivity without problems.I turn it to prospect mode and play with the sat does nothing,Still real bad,static, jumpy, crazy thershold.

The internal pot is labeled threshold I do beleave that's what leads me to think this is the problem.Could the pot be defective and need replacing or would it be something else in the circuit.I'm not sure if my meter can test transistors,so Im pretty limited to what I can do.Could i turn this pot-I think it adjusts the tone?Maybe it will make a better connection?

I just got laid off and my last whites repair was costly not to mention took for ever.Then on top of that I had to resoilder the new female coil plug they installed on my spectrum after a hour of use.I sold that machine for a great deal on the forum(it worked just fine when I did).I know people swear by whites service.I swear by there machines,there great,but I must admit they have broken down more than any other brand I have owned.I own a compass machine that's as old as mine works just fine.Maybe Its just my luck with used whites machines.I know my infinium was used but garret fixed for free and payed return shipping.Im hoping maybe whites be just as cool.

I may call whites and get a estimate.I do beleave there email said $45 hour labour,plus parts,plus shipping.Im pretty good with electronics but must admit this is fairly complex stuff!!
Any help or suggestions be great.I may end up ebaying the thing or trying to swap for a old gold machine.I cant afford the repair bill but I paid $425 all said and done for a bunk machine.
I would like to get at least a older working gold machine for it.

 

[DavidRamey]

sounds like dirt between search coil and coil cover

 

[rockpup1]

No.No search coil cover and does it with both coils I have.Like I said its not a connection- Im sure its a internal problem in the circuitry.

 

[DavidRamey]

Then I would send it in to White's

 

[ExpIInut]

This might sound crazy - if you max out the sensitivity does the noise stabilise / remain constant or is it eratic

 

[rockpup1]

Its real eratic past about 7.It gets twitchy just past 3.You just cant get a smooth thershold.Im trading it or selling it.Dont want to offend anyone but my last whites repair job sucked-took 6 weeks and after a hour of use,I ended up taking it apart and fixing there bad soilder job.I know others talk the world about whites-maybe im the one exception.Dont get me wrong about there machine's there top dog.If I get another it will be new or on warrenty and I plan on the MXT Pro.

 

[RounderRick]

Sorry to hear of your bad luck with the used detector I don't think I'd trust buying a used one without the option of taking it for a test run first or it be a dealer and will refund the money if it don't do as it should.
I hope you get everything worked out.

 

[Barney II]

Just call the Whites company and let them know that you are sending it in---you will not get a better response, fix and quick service anywhere else. I can't say anything about the price but , it will be the lowest cost anywhere--------------------Whites =best service going

 

[vito]

Ok I know my machines not working right.I pretty much got scammed on my used machine deal.I put up with the problem for the end of my season.Yielded some returns including a large gold wedding band,but I did better with my big bud 220-D.

I took the machine apart.I think I found the problem.Looks like a inside pot has a bad solider connection.
I'm sure I fixed that.I tried to test but its Canada and wrong time of the year to go outside.I still think the problem is there.

I can run the threshold to zero(silent) and the more I turn up the sensitivity the worse I get a irregular static sound.I can run around 3 sensitivity without problems.I turn it to prospect mode and play with the sat does nothing,Still real bad,static, jumpy, crazy thershold.

The internal pot is labeled threshold I do beleave that's what leads me to think this is the problem.Could the pot be defective and need replacing or would it be something else in the circuit.I'm not sure if my meter can test transistors,so Im pretty limited to what I can do.Could i turn this pot-I think it adjusts the tone?Maybe it will make a better connection?

I just got laid off and my last whites repair was costly not to mention took for ever.Then on top of that I had to resoilder the new female coil plug they installed on my spectrum after a hour of use.I sold that machine for a great deal on the forum(it worked just fine when I did).I know people swear by whites service.I swear by there machines,there great,but I must admit they have broken down more than any other brand I have owned.I own a compass machine that's as old as mine works just fine.Maybe Its just my luck with used whites machines.I know my infinium was used but garret fixed for free and payed return shipping.Im hoping maybe whites be just as cool.

I may call whites and get a estimate.I do beleave there email said $45 hour labour,plus parts,plus shipping.Im pretty good with electronics but must admit this is fairly complex stuff!!
Any help or suggestions be great.I may end up ebaying the thing or trying to swap for a old gold machine.I cant afford the repair bill but I paid $425 all said and done for a bunk machine.
I would like to get at least a older working gold machine for it.

The pot you're talking about is R20 - a 100kΩ pot. It's adjusting the deglitching buffer amp (part of U7). Yes, you can adjust this. If you own a oscillograph and have the skill to use this.
Otherwithe let the whites staff do the job. You'll be amazed about their customer service, if you're livin' in the U.S.

 

[JohninNC]

Hello,
Even if you have an oscilloscope, that might not be the only problem. I've worked on enough electronics to know often a problem can lead to a follow-on problem in later circuitry. Sorry to hear about the job, but the best way to get your money out of it is if it's working properly. Most people won't buy a 'pig in a poke' (unknown problem or repair). I know money might be tight, but that is your best option. The other benefit would be, White's knowing the machine, may be able to fix it quick and cheap. The other side of the coin is if you get it fixed, you may want to keep it. I love my MXT and cannot see ever using a different machine. Hope it goes well with the machine and the job hunt. John