First suggestion for future strip-downs, get an old tin lid, add a magnet, then put all your screws on the magnet. That way they can't run off and hide in the carpet! - - As there was corrosion (rust) inside the head unit, that says that water got in. Check that there is no corrosion on the tiny pins and sockets in the cable leading to the coil, and to the USB charging wire. Take the circuit-boards right out, and closely inspect all the tiny trace-wires on both sides - one of those or a component could have been broken by the corrosion - or there could be a bridge-link that has been displaced. - - When you cut the plug and two wires off the old battery, were the wires themselves nice and shiny, or dull, maybe black. (Commonly called 'black-wire blues). The wire itself has gone rotten and will never make a good contact. - - Those wires should be soldered, not just twisted together. - - The 'hot-spot' on one part of the board will be the charge control circuitry, making sure that the battery doesn't get over-charged - if it is getting hot, that shows that something is working too hard, either short-circuiting, or maybe even open-circuit (not connected due to a broken trace-wire). Does the head coil need to be plugged in before the head unit will wake up? - - - The best option is to find yourself a local radio ham, and see if he can give the head unit a good 'looking at' - as he/she will know what to look for, and how to fix it. I could do it, but can hardly just pop round, as I'm in the UK! - - - - As you have discovered, lithium polymer or lithium ion batteries do NOT like to be run down to zero volts, that is instant death. They need to be kept charged to about 40% of full until you want to use the device. The trouble is, a lot of electronic devices these days do not have a 'hard' on/off switch - a physical circuit-break switch, but use these press-on press-off things that keep a little trickle of volts going all the time, or they cannot know when they are being called to switch on! If you like, they are in 'stand-by', not completely off. - - So - EVERYBODY - keep an eye on your detectors, etc, and charge them up now and then - or you could have a little bonfire on your hands. (aka electric bikes, scooters, and even cars!)
I've been an electronics tech around 20 years on the Gulf Coast and I can tell you that having worked on equipment on the coast for so long that your machine probably has corroded parts that caused the battery to go bad in the first place. Attatching the new battery and leaving it plugged in will only short it as well. The place you felt the heat coming from the board is where you will trace the issue back to, because that is where the corrosion caused the short that shorted your battery. If you can get the boards apart, it's actually possible that you may be able to clean the boards with electronics cleaner spray and remove the corrosion with a brush. Just don't use a metal brush. There are brushes for cleaning electronics. All of these things are true if the board didn't already overheat to the point of damaging the board too much. Also, solder the battery cables, don't just twist them together. They can corrode very fast just twisted together leading to future problems with the battery, otherwise, he put them together fine.
Wires should have been soldered. You will eventually get corrosion between the twisted wires as you detect around salt water. Next time just fly me down from Ottawa 😅. It's cold here. You may have damage on your circuit board.
My suggestion is to save up for XP Deus 2. I used the Minelab Sovereign for years and had battery issues. The jump in Technology is amazing. Have Fun 😊
My wireless mouse had a battery pack very similar. Stopped charging, opened it up and it was puffed. Been getting random suggestions now, that youtube algo is amazing
mAh = milliAmphere hours is a measure of how much current the battery will discharge in an hour. The replacement is slightly less, so it will not last quite as long between charges, but as long as the voltage and polarity (+/-) is the same, it should work. Seeing the corrosion on the inside, some moisture probably got in at some point. You may have fried the charging circuit when you plugged it in the first time. You can try looking for corrosion on the circuit board and cleaning that up, but the damage may already have been done.
The electrical smell is a good indicator that there's something shorted on the board. Usually smd capacitors like to do that. This can actually be the failure mode of the detector. The old battery could have puffed as a result of a short circuit on the board that overloaded it. You probably shouldn't have left the new battery plugged in for 45 minutes because you can also damage the new one. I would suggest unplugging the battery and measuring the pins on the board with an ohm meter. If there's low resistance between the positive and negative of the battery connector it's likely a nearby filter capacitor. It could also be a charge controller chip or something else that's gone bye bye. You can further diagnose what gets hot using denatured alcohol: remove the green board from the housing, connect a charged battery to it, and apply alcohol around the hot area with a piece of cotton or something else suitable for that purpose. The alcohol is going to boil and evaporate from the shorted component very quickly. In any case this is getting to the point where a person with no experience in electronics can't do much more. You can either give the board to a repair shop to diagnose and repair, or consider the detector a lost cause. Keep in mind that when something shorts on a board like this it can also take out nearby components. So the repair could be more complex than replacing a single chip, or removing a bad decoupling capacitor.
First things first for your detector(s) if you are in the salt water with them... Always rinse your water proof detectors off with standard water... And Def don't use high pressure when doing it. This needs to be done every time. Or you are going to continue to have these problems. Also, the FL heat can get pretty scorchy if your detector is in your car for long periods of time. I always have window shadow reflectors if going to lunch after detecting. And Def crack the windows as well. I always remove the coil cover and rinse as well as not doing this every time will affect your detector readings eventually.
You being a diver should have some silicone grease. Put a small amount on the o ring for the cases and any o rings for the cables. Get some dielectric jelly for the connections. Make sure the voltage and polarity of the batteries are the same. If that doesn't work, then pick up that equinox and go find a big fat gold ring.
i really enjoyed watching you open up the detector. i'm guessing, but i think something fried way back at the beginning when the initial charge failed. thanks for the bloopers!
Yeah, it fried because she wired the battery backwards. If you look a the batteries side by side one is a positive 3.7 volt rating and the other is a negative 3.7 volt rating.
Inspect first circuit board closely with magnifying glass for bad/melted solder connections at pins, melted strips and crossed/internally melted together plug connections. If no issues on first board inspect display/controll board for same isssues. Sometimes components on board can also be damaged by over voltage, would look for discoloring around area's where board was hottest. Other than that would just replace or send out to professional/factory for repair.
The rusty screws is a clue of saltwater intrusion inside the head unit...My guess is that there was some corrosion on the board causing a short circuit and the board to heat up......The battery being swollen may or may not have had anything to do with the original problem of why it woundnt turn on...I would cut my losses and buy a nokta double score for $425...multi frequency and will handle saltwater much better than the multi kruzer...
if u feel heat or smell something burning wise i would look at the cricket board by the batter on the side u could not see check it for brown burnt spots or solder joints that might of got hot i had a power window regulator nissan wanted 180 for the part i removed it out of the box and re solderd every connection to freshen it up it worked to save me cash
I would have soldered the battery wire connections. Next I would use a volt meter and measure the voltage at the batter connector. The fact that things are getting warm would suggest that there is at least some charge in the battery. Does the display do anything when you turn the unit on. One other thing you might try is to have the search coil plugged in when you turn it on. Other than that you may have to send it in to the manufacturer to get it serviced. Good luck !!!
Little disappointed with Nokta on this. I would have thought they would have used Stainless steel screws, instead of regular steel. Also you would think they dabbed a bit of die electric grease on those pins and lastly apply a water proofing spray/coat on the PCB board. I've been rebuilding vehicle modules for many, many years and seen better quality on cheaper cars. But I like the Benny Hill Music!!! Bryan, Vero
How do you check if a battery has a positive or negative rating? Use a multi-meter and put the red lead of the meter on the red wire and the black lead of the meter on the black wire. If the voltage reading comes back as -3.7 volts than you have a negative voltage rated battery, if it comes back as +3.7 volts than you have a positive voltage rated battery. Although I'm thinking that you cooked the detector when you wired the battery up backwards.
Electrical engineer here. The voltages on the batteries were the same, so unless the motherboard just has a weird detection chip that rejects non-authorized batteries (unlikely) then it should have been fine. My best guess is that 1) when you spliced the wires, the connection wasn’t good enough to deliver the required power, so it was trying to pull current from poorly spliced wires, causing them to heat up. Or 2) perhaps some corrosion or something happend on the motherboard preventing it from powering on or charging properly My recommendation is if you can get your hands on the EXACT battery intended for the machine and try it. If that fails, it’s likely it’s the board Hope this helps!
well the salt air environment you live in can cause all kinda problems. move you detectors inside you home where air humidity is controlled by you hvac system. keeping in your garage with all that salt air and humidity kills electronics
As you are not likely to fly me and all my equipment to warm sunny Florida I think this is your best option. Not sure of the cost. Garrett charges about $50 and shipping to repair the AT Pro.
So I watched your video and read all the comments so far. Amazing that these “so called” electrical experts didn’t point out the most obvious problem. You’re lucky that the battery DIDN’T explode in your face. Your old battery is rated at 3700 milli amp hours with a negative 3.7 volt. Your new battery is rated at 3500 milli amp hours with a positive 3.7 volt. Even though you matched red to red and black to black wires one is a + voltage battery and the other is a - voltage battery. If you wire it red to black and black to red it should work.
I dont think the new battery is the issue. Seeing the rust inside makes me think it got to some of the components and is shorting them. With your level of electronics experience, you could remove the boards and scrub with a stiff plastic bristle brush, using isopropal (sp?) alcohol. That may be enough to clean out any shorts. If you are lucky the things that were getting hot were not damaged. The next step up would be to test diodes and transistors with a multi-meter, looking for shorts or opens.
