Harbor Freight 9 Function MD Mod Help?

Your link doesn't work.

New link

Try this?

http://www.treasurenet.com/forums/m.../306836-12-pvc-frame-water-resistant-mod.html

Seems like a lot of work to avoid buying a reputable machine.

When I buy something from Harbor Freight it is generally something I need on a very limited basis and will not be concerned when it falls apart on me. It's been my experience that they sell low end quality tools with a limited life span. If it's something I need long term usage out of I go with Craftsman or something similar.

I'd expect the same from a metal detector from there.

mlrosier said:

I've been interested in giving metal detecting a go for a very long time, but could never justify spending a bunch on a decent detector. Then I found out about the Harbor Freight 9 Function Metal Detector. I bought one, and I decided to mod it up before taking it out. The materials are really flimsy.

So, I'm trying to replicate this mod:

http://www.treasurenet.com/forums/me...stant-mod.html

I'm wondering if anyone can help me out here. I gutted the HFMD9, and set it up the same way as the detector in the above. I desoldered the coil cable from the main board, as well as the useless meter. I got everything packed into the wet box, resoldered the coil cable to the board, but now, when I turn the detector on, all it does is beep, at everything, metal or not. Just holding the detector still, all it does is chirp non-stop. Is it because I did not re-solder the meter to the board? I'm pulling my hair out and I am about to give up and just junk all of it. I took a picture of the main board before I desoldered it, so all of the wires are back where they need to be. I don't see any terminal bridging from solder that could be causing a short. Do I need to bridge the "+" and "-" where the meter was wired to the board? Any help would be great! Thank you.


Update:

I soldered the meter back to the board. Nothing has changed, except now, the pitch of the peeping increases in step over 5 seconds, stops beeping, and the detector goes dead and won't respond at all.

Click to expand...

Did you check for possible cold solder joints? Not having the meter shouldn't affect it? I wouldn't bridge the +/- pads either, just saying because I realize you put the meter back in place... just wanted to still throw that advice out there anyways. Also, sorry but I still have to ask, are you SURE you soldered the coil wires back the same way that you took it off? What you are experiencing sounds as if it doesn't "see" the coil as being connected and/or, again, a cold solder joint? Did you possibly have too much heat and "lifted" the solder pads? Finally, I noticed in the pictures that the electrical components are "loose", including the batteries/holder in the box? By you putting the meter back in place and you get "different issues" now tells me that, obviously, you are having intermittent issues So make sure that nothing is touching what it is not supposed to be touching, again, including the batteries.

NOTE: this is all based on all wires being put back into their original spots and the MD'r worked from the very start before taking it all apart.

Sounds like it was straight forward for the most part?

If you get it to work HH \_ with it.

Just for "kicks", I might do the same I like the mil look to it

Chipk said:

When I buy something from Harbor Freight it is generally something I need on a very limited basis and will not be concerned when it falls apart on me. It's been my experience that they sell low end quality tools with a limited life span. If it's something I need long term usage out of I go with Craftsman or something similar.

Click to expand...

(slightly off topic) I agree in general. Some of their items are worthless... however, their Pittsburgh line of hand tools are quite good and have lifetime replacement policy just like Craftsman.

(back on topic) That being said, I still have my HF9F and I remember trying to use it at certain times where it would just chirp, chirp, chirp in a regular rhythm while outdoors and no amount of sensitivity adjustment would get rid of it. However, if I brought the coil up to where the shaft was horizontal to the ground, the chirping would stop. Maybe the OP is experiencing this.

Papa

May have nailed the problem, indoors is dirty with interference. Have you taken outside and tried it? The coil is like a radio antenna, picks up everything. The circuit board is suppose to sift through the muck. Just guessing, but the circuitry probably isn't really sophisticated, and capable of performing well in a noisy environment.

HarveyH48 said:

May have nailed the problem, indoors is dirty with interference. Have you taken outside and tried it? The coil is like a radio antenna, picks up everything. The circuit board is suppose to sift through the muck. Just guessing, but the circuitry probably isn't really sophisticated, and capable of performing well in a noisy environment.

Click to expand...

And here I'm assuming the OP was having these problems "outside" Yes, indoors is NOT an ideal place for a detector!!! You will pickup the floorboard nails, piping, who knows what? Take the "heater" (a.k.a. Metal Detector) outside when turning ON and TESTING or make darn sure you're NOT going to pick-up any type of environmental surroundings. You even have to take EMI into account as well.

HH \_ and hope it works

Another thing that slipped my mind... Is the battery good/fresh? A 9 volt battery is considered spent at 6 volts. I got in the habit of putting batteries on the meter, first, before blaming the circuit. Really embarrassing to tear something open, do a bunch of tests, just to eventually figure out the batteries are bad. You can occasionally get a bad battery out of a package just bought. I bought a nice bench supply, few years ago, don't rely on batteries much anymore.

Wow. Thank you!

Wow, thank you for the replies! I may go through and flux and resolder all of the points I messed with. I'm thinking I probably damaged the board when I was de-soldering the wire holes for the coil wires. I didn't have an braid de-solder, and used a suction pen instead, so I had to try a few times on each hole. I had too much caffeine and my hands were shaking. I checked for anything touching, and I don't see anything. However I did notice one thing, when I move the coil wire in the box, the beeping fluctuates. I think I screwed up, and might just cut my losses and headaches. I'd like to get a Fisher Gold Bug II, or something else decent. I really want to look for gold and meteorites in the mountains.
If anyone has one that they don't want anymore, I'd be willing to do some trading for things. I have a Lenovo Yoga 2 that has barely been touched that I can trade. I'll include my Harbor Freight 9 Function for the heck of it. lol. I can also throw in some odds and ends. I have a bunch of high end knives. I have a Paul Chen sword. A Sony Stereo Surround sound system. I'd give it all for a good detector. I don't use any of it.

mlrosier said:

braid de-solder

Click to expand...

Personally, I don't like to use this as it requires heat at one particular point for longer than I would like... I ONLY use de-solder braid if I absolutely have to... with that said, see the next comment below...

mlrosier said:

suction pen instead

Click to expand...

I have a suction pen as well or what I like to call "solder sucker". The spring loaded activated "wand", if you will, just requires you to "melt" the solder and then quickly press the trigger and up the solder goes. Now, with this said, and it sounds like a contradicting statement, it MIGHT/CAN pull the solder pad as well, but, for me at least, there is always less of a chance of this happening. Even the more expensive "de-soldering stations" that you can buy will have a tendency to "lift the solder pads and/or vias" as well. Sometimes it just can't be avoided. So going back to the de-solder braid, I only use it on bigger pads and only if I have to. I do NOT recommend using de-solder braid on surface mount pads, which I highly doubt you had surface pads to deal with with the wires and such.

When moving the coil wires and it fluctuates, I would THINK that this would be expected because it is like moving the coil wire that goes down the shaft and it picking up "erratic" movement and the sensitivity is "kicking in" Just a thought/guess on that

Harvey did bring up a few good points as well in his posts. I tend to make things harder than they are sometimes and my boss sometimes tells me that Look at the voltages first, like Harvey suggested, even at the source (i.e. the battery) Harvey A 6V source on a, more than likely 5V regulator (i.e. the unit more than likely has some sort of 5V uController and other devices), will more than likely cause erratic behavior. So check battery voltage(s) first.

And finally, as for papaharley's comment, I don't know anything about how the unit reacts "normally", so I would give his comment/post a thought as well.

A few things to consider and think about.

HH \_ and hope you figure it out

Ah well.

I'm going to try and resolder joints and new batteries to see what that does. If that doesn't work, I have a possible opportunity to get my hands on a Garrett GTI 2500 with five coils all together for $400 if the guy will let me put money down and pay payments on it like a layaway. Is that a good deal?

If re-soldering the joints, fresh batteries and testing outside do not fix your problem, try reconnecting the meter - even if just temporarily. The absence of the meter MAY change the circuit performance. Also, it is not necessarily safe to simply jumper across where the meter was previously connected since meters have significant internal resistance. Again, the circuit design dictates what needs to be done to safely remove the meter. Hope this helps.

mlrosier said:

I'm going to try and resolder joints and new batteries to see what that does. If that doesn't work, I have a possible opportunity to get my hands on a Garrett GTI 2500 with five coils all together for $400 if the guy will let me put money down and pay payments on it like a layaway. Is that a good deal?

Click to expand...

uhhhhh... YEAH How hot is it... ain't talk'n about the ground/rocks I've had my GTI2500 for just over a year now, but don't use it that much. It's NOT the machine, just me. It does have a bit of a learning curve... well, to me at least. I'm so used to the ACE250, just turn on and go type of thing. I have to admit though, if this is your "1st" MD'r then expect even more of a learning curve It does way more than the 250 does. But if you have the patience and you can get it for that price, then I would say go ahead and get it

Or look at it another way, if you have $400, then try to get a hold of a sponsor here on the forum and he might be able to hook you up with something that does fit you Who knows

I try not to "sell" detectors... I just give my humble opinion and whatever experience I have gained and just pass that information along to the next guy. Some people are just stuck, I mean stuck, on one particular brand only I only have Garrett's but that's only because... well, I bought the things It doesn't mean that I won't ever buy a Tesoro Sand Shark, which is still in the back of my mind or a Whites DF or ID300. I mean, what else is there to say Anyways... I would talk to a sponsor at this point before handing your "grip" over for the GTI2500. But yes, it is a good deal, in my humble opinion.

HH \_ to you

Toewe said:

If re-soldering the joints, fresh batteries and testing outside do not fix your problem, try reconnecting the meter - even if just temporarily. The absence of the meter MAY change the circuit performance. Also, it is not necessarily safe to simply jumper across where the meter was previously connected since meters have significant internal resistance. Again, the circuit design dictates what needs to be done to safely remove the meter. Hope this helps.

Click to expand...

The problem is is that he did re-insert the meter and it didn't work then either:? I'm thinking 1) the wires are not in their correct spots and/or 2) a possible cold solder joint. The first one being the most likely cause, but who really knows at this point

HH \_

Very difficult to tell from home.

Toewe said:

Very difficult to tell from home.

Click to expand...

Indeed Toewe. Now a GTI2500 might be bought I don't "sell" detectors, if you get my meaning. I will give the best advice from my own personal experiences or pass on information that I've learned, but that is just about as far as it goes. I would, on occasion, tell someone to look into a, for example, ACE250, only because that is the machine that I have and use the most. Other than that, it is just a "suggestion" and not HERE... GET THIS... type of thing Anyways, if a GTI2500 can get bought with extra coils for that price and it is in pretty good working order then, yeah... why not. But for $400 the OP can get a "newer" machine and possibly one that fits him better, which is why I suggested a forum sponsor for the OP to talk to. Well, I guess this is a "wash" for the most part and on to other threads.

HH \_ Toewe

Minelabe X-terra 705

The guy that is offering the GTI 2500 is also selling a like-new Minelab X-Terra 705 for $350 with two coils. After looking at reviews and current pricing, it's a newer detector, and sells for close to $1000 now for the dual coil package. I think $350 is a steal if I'm not mistaken. Better than the GTI 2500?
Also, the 705 comes with 6" and 9" 7.5Khz coils. Are those good for prospecting or no?