PimentoUK

The beeper cover is just a push-in item. If you poke a blunt tool into the slots, you can pry it off. From memory, there are two fixings, one at the rear, on at the front end. Inside, there's just plain (thin ) plastic, no electronics gubbins etc gets exposed. It should be easy to clean out.

"Not sure what model the white one is?" It looks like a First Texas case, I'm thinking it's a Bounty Hunter Discovery 3300.

Here in the UK, we occasionally dig up the carbon rods from carbon arc lamps. They are quite large, about 0.5 inch / 12mm diameter, lengths 2 to 4 inches / 50 - 100mm. One of mine was marked with the German manufacturers name, which is how I identified it. I presume the lamps were being used out in the fields, so harvesting etc could continue after dark ... though it's possible they were simply dumped there, along with every other kind of rubbish. But they do give a good signal.

There's plenty of old Whites catalogues on Sven's Treasurelinx site, you'll likely find it listed in one of them. I assume late 1970's ? Treasurelinx Whites

Here is a technical article that goes into some detail about charging, discharging of lithium cells, and how it impacts life-span of the cell: battery university link

It does sound like a battery problem. Batteries in general are not the most reliable things, they can fail quickly, slowly, when the battery is quite new, or after many years. Have you tried plugging in a 'power bank' battery , into the USB charging port? That may keep the internal battery topped up enough to make the machine useable, so at least you can carry on digging the treasure. If you do decide that a new battery is required, there are two options: A genuine Minelab battery, complete with the right plug, so it's a simple swap over, or: Buy your own seperate cell, and transfer the cable and plug over from the old one. Cell size is '26650', and you want to ideally get one with a capacity of 4800 mAh or greater ( 5500 may be the largest, I recall ). You don't need a 'Protected' cell ( with internal electronics ), but a Brand name type is recommended, as there are plenty of 'Lucky Golden Sunshine' / no-name-at-all types out there. Ones designed for vaping, or high-power flashlights are a suggestion. Obviously you will need electrical skills to do this work. Minelab branded replacements are approx 40 Dollars, a single cell about 10 Dollars. "Your battery should last a lot longer than 1 1/2 years. My original 800 battery is still going strong since Feb. 2018." Mine too, but they can fail inside a few months. "I charge my battery after every outing so it's always up for a day's hunting." This actually can contribute to a reduced life-span. I imagine most people do this, it seems a reasonable thing to do. Unfortunately, being fully charged to the maximum 4.2 Volts stresses the battery, and reduces life-span. It would be better to leave the machine with a part-discharged battery, and top it up shortly before using it. And only charging it up to 4.0 V would be ideal, if you're not the "11 hour hunt" type of detectorist. But that's not an option with a built-in battery ( and built-in charging electronics ). I mentioned in the "How can the Equinox be improved?" thread that it would be useful to actually have a more accurate readout of battery voltage / state-of-charge. There's an "88" display on the screen. Using it to display "41" for 4.1 Volts etc would give about 8 steps resolution ( 35 - 42 ); or have a '0 to 9' scale, example "b5" for '50%+' , "b9" for '90%+'. Have it work with the coil disconnected, as that's how the machine will be when most folks charge up their machine.

It's likely that someone on the Geotech1 forum may have some answers: geotech1 forum However, the M6 is a single-freq detector, there's no way that will have coils compatible with CZ multi-freq machines.

"I've also had .. strong signals that turn out to be nothing. Ie a 13 or 14 on the screen with strong tone and seemingly 3 or 4" deep but nada when I turn up the turf" Sounds like a common Park2 ( or Field2 ) issue. Caused by large deep iron, especially if it's 'loop shaped', like nuts, washers, chain link(s) , iron buckle, horse bridle joining rings. Changing to Park1 ( or Field1 ) and seeing if it's 'still there' is one technique to try. Also .. pinpoint mode doesn't "lie" , if it indicates something is there, it's almost certainly right. So you know to keep digging, if it's not in the top 4 inches. This is where an electronic pinpoint probe could show it's use, as putting it into that 4" hole, it would likely get the target at 7", maybe more if was a large item.

"This may not be a Big deal but I just wanted to bring it up.. " It's well-known, hence me mentioning it in my last post: Quote: "The answer is a big NO. They consist of a lithium cell, ( about 800 mAh capacity ), with some magic electronics board [switching regulator] integrated in the package, to drop 3.7V down to 1.5V. They are not what you need, they produce electrical interference, and need a special charger. The idea of just one of these switch-mode regulators is bad, but a pack of 8 of them, for example, is not going to get my vote at all. For what it's worth, the regulator will likely operate at about 1 Megahertz, so some way above the main detector frequency, but that doesn't stop them potentially causing interference. For what it's worth, there are many detectors with switching regulators integral to them, everything from an ACE250 to a Teknetics T2 to an Equinox. But if it designed properly, the risk of problems can be eliminated.

Quote:"Anyone angry with me yet?" For posting off-topic? This is a friendly civilised forum, we can tolerate that. So, while we're off-topic, here's a few reasons to have a pinpointer, and a few disadvantages: older pinpointer thread

Quote: "I have my original Garrett ProPointer from years ago ...The tips are scuffed from use but I'm never worn one out." Well they DO wear out, I wore through my original black Propointer. It was hard to spot, as the ferrite rod / coil is encased in black resin "potting compound". There was a slightly shinier black bit, contrasting with the duller black of the case. But it was still working fine, so that's when I started protecting it with a short ( 45mm / 1.75" ) length of regular heatshrink sleeving. I completely removed the totally pointless 'sifter blade' , leaving a nice round tip that the heatshrink fits on. The sleeve does have a tendency to slip or move, so I started glueing it after shrinking to fit, using a low-strength adhesive. Evo-Stick, bicycle tube puncture repair glue, both seemed OK. the heatshrink lasts a few months before re-fitting / replacing. The pointer is still going strong 7 years later.

The coil size will make no difference, nor will the Minelab / Coiltek make, as the electronics board inside the Coiltek coils is a Minelab-supplied board. Running the machine on the internal loudspeaker is a definite way to increase power draw. ( though not if it's silent, of course ).

"So, 9 hours from full charge to flashing 1 bar in a minimal activity setting" That doesn't sound terrible, but is a bit below what I would expect. I would say 11 to 12 hrs from full charge to "diddle-biddle-diddly-do-dah" turn-off would be normal, when running earphones, Bluetooth/Wi-Stream turned off, backlight off.

AccuPoint seems a decent product name for a pinpoint probe ..... but there are many other manufacturers with the same idea. Anyone have a laptop with an Accupoint pointing device? Sometimes called a nub mouse (or another less polite name), popular on Toshiba's. Nice to see there is already a selection of rubber protective tips available for it: accupoint rubber

A simple introduction: PLL introduction PLL phase detectors An advanced course, pdf: advanced PLL The CD4046 PLL IC datasheet pdf: CD4046 datasheet I do not know how this XOR gate phase comparator is used in the Goldbug circuit. Maybe to synchronise one oscillator to another ? The "slave" PIC micro that is used to drive the complex LCD will likely operate at a lower clock frequency than the main "brains" PIC. Having two micro's generating independant electrical interference could be a problem for the analogue parts of the circuit. Synchronising one micro to the other may help control this. It is a technique I have seen versions of in several metal detector designs.

The XOR gate is used as a digital mixer. The digital output is low-pass filtered, to give a DC voltage. This DC voltage varies as the phase relationship between the two logic inputs varies. It is a common part of a phase-locked loop ( PLL ) circuit, for example the CMOS CD4046, which has 3 choices of phase comparator.

I saw the thread on the Geotech1 forum. Advice : Try not to argue with Carl, he knows what he is doing. So I think my earlier advice about removing the two / three capacitors and resistor may be a solution. If it does not work, re-fit them, and purchase the XOR gate IC.

People are even less likely to open their machine now, as we have determined that very few machines actually have this part fitted on the PCB. Perhaps only very early models had these mystery components. Here is another good photo, located here on this forum: G2 PCB As you see, the parts are not fitted An F19 WITH the parts fitted, but hard to read: F19 with parts fitted Try and work out the pinout of the missing part. Is it connected to the same power supplies as parts U1 and U2, which I think may be op-amps ? Or is it connected to logic voltages, perhaps the same supply as the PIC microcontroller? Single analog switches normally have a standard pin configuration, for example see here: single switch SOT23-5 Likewise, op-amps also have a common pinout: single opamp

"It is strange that no one should have such a device." I an unsure what you mean. If you are surprised that no-one else replied with an answer, I should point out: * Your English is poor, many people will not understand your original question. * Your question is highly technical, about the electronic innards of a detector. People on here USE detectors, they don't build them, repair them, modify them electronically. You should register with the technical Geotech1 Forum, where you might get some response. *I am sure there are many people on here who own a G2 / F19 / Goldbug Pro / or a clone. But they are not going to dismantle their detector to answer your question, for a multitude of reasons. ------ Here is the Geotech1 Forum that I recommend joining: Geotech1

I can only speculate what is the purpose of these parts ( IC, resistor, capacitors ). Sometimes components are fitted to help calibration or testing of the detector, but they serve no actual function when the detector is used normally. ( The Fisher F2 has two resistors fitted between the demodulated X and R signals, with a test-point on the junction. These resistors could be removed with no effect on the operation. ) One thing you could try is removing all of the "unnecessary" parts from the PCB, and see if the machine then starts working. Do this carefully, as you may need to re-fit them again. Tip: resolder them on one terminal, that way you cannot lose them or mix them up . My hunch is the missing part could be an analogue switch, single-pole ( like part of a CD4066 ) or a single op-amp. [edited]

I found a photo of a genuine Fisher F19 / Goldbug Pro ( a G2 equivalent ) , and that also has U7 and a few other parts not fitted. It is shown on the MD-Hunter site: Fisher F19

That is an interesting part of the circuit. I found two photos of a Chines copy of this machine. Neither have this component fitted. Does your detector function without the part U7 ?

We need photos. What is the part marking on the device? Maybe C20A, or LTAFJ ?

Farmer Peter Whatling (R) and detectorist Eric Lawes (L) , photo taken approx 1993.

From info posted on Tom D.'s forum, the Sunray brand was under new ownership ..... but the new owner passed away. Maybe this link explains: dankowski detectors link