ignore the fact that you could have a bad detector and/or a bad search coil. of the two my money would be a bad search coil, but it's hard to say w/o having it in-hand.
One problem comes up whenever someone posts a "help me", but there isn't ample info for readers to help with. In your case, some of that is possible because you are new to metal detecting, and probably are not that familiar with some input that could help. For example, it would be good to know the following:
Type of ground you are 'testing' in.
The Ground Phase read-out at the location you are doing the tests (on the MXT that is reported in the Prospecting mode).
The Discrimination and Sensitivity/Gain settings you use.
Is there a 'proper' Threshold setting used?
Are the sample 'test coins' passed across the coils center axis in a 'flat-to-the-coil' position?
gglav said:
Im new to metal detecting
So, lacking any experiences with other makes and models you're probably also lacking any pre-experience of what is anticipated or required for proper performance. It takes time to master any detector, even for an experienced user.
gglav said:
i had got a used mxt pro over the winter with the 10" D2 coil anyway after 3 months of using it ive notice it cant find anything deeper the 4 inches unless its a big object not a coin.
It shouldn't have taken 3 months to figure out if there was any 'poor performance' or not. Any detector can be "air tested' indoors or out, even during a stormy winter, so by now something should have clicked to start inquiring.
I'm also curious, as I always am when I read of a newcomer selecting a particular make or model is 'Why?' What prompted you to select the White's MXT? It is a very good detector, but not what I would call a 'starter' for most people, so I am curious about the types of sites you had planned to search, what you intend to search for, and why you picked the MXT?
gglav said:
so today i did a master reset on it
Please explain to me what you mean by a "Master Reset" with the MXT.
gglav said:
changed the batterys and i did a field test and i used a penny and quarter at different heights 2'' 3'' 4'' 6'' 8'' 10'' and i wasnt surprise it couldnt pick up anything after 3 to 4'' so now i know somethings wrong
Were the batteries bad? How low was the voltage?
By "field test" did you actually test the MXT with targets positioned
on the ground rather than a simple "air test"?
When you say you couldn't pick anything up beyond 3"-4", are you referring strictly to hearing any audio 'Beep', or are you also referring to seeing a proper TID or VDI for the particular target? Remember, TID and VDI can be inaccurate if the target is too far from the search coil, close to a masking target, in a bad position, or mixed with challenging ground conditions, such as intense mineral bodies (rocks, dirt clods, etc., etc.).
gglav said:
its in like brand new condition no scratches or signs of it being dropped or abused
That's good that you received an undamaged or unabused detector. I hate it when people offer a well-worn detector but try to suggest it is in good condition. But there could still be a problem with a detector and/or a search coil. This could be especially true if it was an early-release 10" 2D search coil because there were some that had a problem. I know because I had two of them.
gglav said:
does anyone know what it could be should i send it to whites i dont think it will be covered since its second hand
What it would be is a checked-out and properly operating detector and coil. They do great work in Sweet Home, Oregon. It's just too bad that you didn't take care of this during the prior 3 months and before your pending camping trip. If in doubt, now or after your trip, it wouldn't hurt to send it to White's for a check-up. First, however, is to check out the search coil as well as your control set-up and testing methods. I'd be willing to bet that the search coil might be the 1st point of concern.
gglav said:
i was think about buying a new coil plus if i send it in who know how long that will take. i leave camping on the ocean next week the reason why i got it. if the chances are high that its the coil i was thinking of geting White's Eclipse Deepscan DD 8x14" Search Coil if thats it a bad coil but im not even sure that it could be the coil or the machine it self. if anyone has any info or anything please help
IF you send it it won't be back in a week, but it would be good to check out a different search coil.
Probably the LAST search coil you ought to consider is the 8X14 DD. I love the MXT and M6, having had several of each, and the 6