F75 LTD on the fritz or simple fix?

[grumpy]

My F75 LTD started getting lots of static and noize in it lately and finally got unusable; I changed the coils with no change and finally got the batteries changed , still no fix. Last result I just took the coil completely off the machine and it still growls and pops dif numbers up. Im guessing its in the brain board or something. If anyone else has had this happen and found a simple answer please pass it along, hunting is to good to be home without a md.
Thanks
Grumpy

 

[Elton]

Did you try the simple factory reset grumpy ?.. Another thing that sounds dumb is the batteries you use make a difference with the F75 series... Must be high quality Alkalines for proper operation.. That is even in the manual if I recall correctly.

 

[SteveP(NH)]

Here is a quote from Page 8 of the F75 manual ...

"BATTERIES
The F75 requires four AA batteries.
These non-rechargeable chemistries may be used: Alkaline, Nickel Oxy-Hydroxide
(Panasonic Oxyride or Duracel PowerPix), and lithium iron disulfide (Energizer L91).
Nickel metal hydride and nickel-cadmium rechargeable chemistries may also be used."

I have used both alkaline and NiMh batteries in my F75 and it picks up targets the exact same in my test garden, including a weak signal on the 12 inche deep mercury dime in discrim and a clearer signal in all metal. I have also used both in the field and other than how long before the batteries need to be replaced or recharged there is no difference.

The F75 like all other modern detector designs uses a regulated power supply with the minimum voltage (in the case of AAs) set at the equivelent of .9v per cell. If you understand electronics at all that should be enough said, as either the machine will be powered up or it won't and that is all the effect that a difference in batteries can possibly have on it.

You can try a reset - but if the machine is falsing without a coil attached then it likely has to go back for repairs.

 

[grumpy]

Working on the problem ; got some of it figured out I think; but some is still i think in the machine;
I took the cel phone out of my pocket and the blue tooth conversation equipment from my hearingaids and quite it down a bit BUT

It is still reading a problem; When detecting with the disc. set at 20 or 25; sens 60 and 2f ; nothing should read below the disc setting right? Well i swing over some things and the machine grunts like a pig and reads like 4 or 7 or 6 ; other than that it seems to be almost as quite as it originally was but not quite; My idea is it still has a bad chip in the mother board or somethin.? Im not a puter person but I still smell a rat in my fisher?

I have noticed that the f 75 has always been sensitive to outside elec. interference.

Thanks for any ideas; gives a guy something to make him feel he is not going pulm nuts
Grumpy

 

[Elton]

My referral was for not using standard AA Heavy Duty batteries..........

 

[grumpy]

Elton;
dont think batteries are a problem; using the same type i have been using for a couple years now. but i did put in new batch of them.
Grumpy

 

[tvr]

Grumpy,
Did you try the factory reset that Elton suggested? My F75-LTD sometimes kind of looses it's mind after sitting for a couple days between hunts. Gets very chatty, won't ground balance, won't find a dime sitting on top of the ground. A factory reset brings it right back to a wonderful metal finding beast (so far).
tvr

 

[Elton]

This will for certain cause the machine to act up.. Some of the connectors are a little tight and feels like it is snug, but it isn't..

 

[DanS]

My F75 LTD started getting lots of static and noize in it lately and finally got unusable; I changed the coils with no change and finally got the batteries changed , still no fix. Last result I just took the coil completely off the machine and it still growls and pops dif numbers up. Im guessing its in the brain board or something. If anyone else has had this happen and found a simple answer please pass it along, hunting is to good to be home without a md.
Thanks
Grumpy

Hello,

New member from Sweden.
If you here a iron grunt at that disc setting then you probably have notched in iron. Happend to me once. Try a factory reset as suggested or notch it out again.

Dan