Home Metal Detecting

The miraculously accumulating machines!...

ZotZot Posts: 825 ✭✭✭
An interesting day...

I went out early this morning, only to find that my trusty White’s Surf PI appeared to have thrown in the towel. Just beeping a constant shrill tone.
I was pretty sure that water had finally gotten the best of it, as my last trip was a proper water detecting stint with the machine floating around a lot.

Soo….. I got back home, onto the Internet, and within 10 minutes I had ordered a White’s Surf dual field, and a Minelab Excalibur II. This was probably one machine more than I really needed.

With that done, the next part was to see if the old thing could be salvaged (in hindsight, I probably should have started with that..).
Many moons have passed since I did any serious engineering, but this should be a fun little project.

First step was to open it up, which was somewhat fiddly and required screwdriver & fingers-coordination due to locking clips keeping the interesting parts hidden from view.
After some minutes of irritation, I had it open:

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There was a bag of silica gel under the circuit board. It was wet, probably the wettest part of the whole machine. It's been there for over a decade! I'm surprised it hadn't grown legs and knocked on the box wanting to be let out. image

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The circuit board is quite small. These really are simple machines. A few dozen very basic components.

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…and now the board is loose for closer inspection.
I wish I had the eyesight and hand precision of 20 years ago. Those damn connectors are small and delicate. Was pleased not to hear any sounds of plastic cracking…

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I spotted a potential short due to a resistor whose legs had been mutilated by the battery connector plug, so I straightened that out.
Some of the integrated circuits looked like parts of them had been running rather hot, but based on which pins appeared affected I couldn’t come up with any failure scenario that made sense, so I assumed they were OK after all.
They have plenty of character though.

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Not seeing anything else obviously wrong, I tried reconnecting the board. No improvement.

After poking around with a multimeter, I noticed an issue with this innocent component, the battery connector.
There wasn’t an open circuit between the terminals (not a direct short either, but obviously something was wrong). The resistance was low enough that the batteries would be fried rather quickly, and possibly the machine would malfunction in the meantime as well.

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It absolutely refused to open in a civilized way, so I had to use a saw to get it open.
Hmm…. That doesn’t look very nice at all:

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But nothing that cotton swabs dipped in Vodka can’t fix!

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Tried the machine again. Still no luck. Damn!

After poking around some more, I noticed that one wire (going to the coil no less) had completely broken and come loose from its connector plug (i.e. it hadn’t just come loose, it had literally broken at the point where its insulation was stripped.

This issue is actually clearly visible in the 3rd pic from the top. Here’s a close-up.
Black wire is loose beside the connector plug, not in it.

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Tested again…. aaaaand the Surf PI is back! image
Works like a charm. Quite interesting that there was more than one issue (at least both the battery connector and obviously the broken cable were separate serious issues).

The twisting tale gives us the following:

-This morning I thought I had one water machine, but turns out I have zero

-Now I have one again. Only took about an hour to get it sorted after all

-Soon I'll have three image ( I'll attempt to justify the Excalibur with it also being a viable rainy weather land detecting machine. Maybe a bit slower on the "add to basket"-trigger next time though). Also: even though the old Surf PI works again now, it's probably on borrowed time. It's really starting to fall apart physically.


Conclusion: It appears I have enough machines. Now I just need to put them on the gold! image

Minelab: GPX 5000, Excalibur II, Explorer SE. White's: MXT, PI Pro

Comments

  • rickoricko Posts: 98,724 ✭✭✭✭✭
    Great story Zot... thanks for taking us on the journey. Old machines do show the wear due to weather, terrain etc., and eventually give up the ghost. Cheers, RickO
  • PRECIOUSMENTALPRECIOUSMENTAL Posts: 961 ✭✭✭✭
    Congrats!

    I also enjoy trouble shooting and repairing just about anything.

    A lifetime spent in industrial electronics and process control comes in handy.

    Should replace the batt. conn. though, just to be safe.
  • ZotZot Posts: 825 ✭✭✭
    Originally posted by: PRECIOUSMENTAL
    Should replace the batt. conn. though, just to be safe.


    Oh, for sure. I can't seem to locate a new one, or a suitable donor device for that matter.
    These are not so common anymore. I'll get it done soon.

    In the meantime...: Frankenstein called. He wants his battery connector back.

    image

    Minelab: GPX 5000, Excalibur II, Explorer SE. White's: MXT, PI Pro
  • pcgs69pcgs69 Posts: 4,258 ✭✭✭✭
    wow, thanks for the story and the pics. Wish I had a bit more technical knowledge like you have. Would be fun to tinker around with things like this to try fixing it. When you get all three, it'll be a good opportunity to do some tests to see which you feel is a keeper.
  • ChrisH821ChrisH821 Posts: 6,293 ✭✭✭✭✭
    Battery snap connector:



    https://www.sparkfun.com/products/91



    Even has what looks like the right plug on the end.

    Collector, occasional seller

  • metalmeistermetalmeister Posts: 4,584 ✭✭✭✭✭
    Good show! I love fixing stuff. When it comes down to it, it is usually a simple fix, bad connection, etc.
    Most just throw products away and buy another when the fix was close to being free. If you can DIY. :-)
    email: ccacollectibles@yahoo.com

    100% Positive BST transactions
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