EXCAL 1000 DOESN'T SOUND ON DETECTION

[sullivan2002]

Hi to all and thanks for reading my message

I need help to solve my problem on my Excalibur 1000.
It works good since some months ago. From the videos you can see, I tried using a normal 13volt power supply to rule out a battery problem. So no battery problem. At fist my problem came and go away. It does not detect anything, only the threshold sound is heard and I can increase by the knob. Generally I use Sensitivity Auto, Volume Half, Discrimination 0:

[video]https://www.youtube.com/watch?v=l5_KrrTV9Dg&t=30s[/video]

and now now the problem is continuous. No detection sound at all

when I approach my hand at the box of the excalibur it seems that it sounds, like a wire from the coil that reaches the box was detached

What to do? in your opinion the problem due to a cable coming from the detached plate to be soldered again?

Is it easy to open my excalibur? can I easily find the two heat-shrinking plastics at the ends of the box tube?

Many thanks for any suggestion to help my Excal problem.

Best

Sullivan

 

[surfman]

Opening it up and inspecting the wiring is easy. Not heard of too many loose wire issues though. Never know. Definitely worth a look.

 

[bootyhoundpa]

Most likely broken wires... i would recommend you watch some old Beechnut utube videos related to replacing the coil prior to taking the mother board out of the tube as can be tricky getting it in and out...also depending which coil you replace it with the wiring be slightly different. .... or maybe you could find someone in your area who has experience with changing excal coil..[attachment 364738 IMG_20171217_142839893_HDR1.jpg]

 

[Ron from Michigan]

This is what I saw in the video, your Threshold is too high and then too low. Turn your sensitivity to max. Your volume is also a gain control turn volume to max. Make sure your discrimination is all the way down. Now adjust your Threshold to just barely able to hear. Important make sure the coil isn't near any metal or interference. I think this may help. Good Luck Ron

 

[sullivan2002]

Hi,

Ron it's not a setting issue. I worked with my Excalibur since 3 or 4 year. I Turned pots in that way just to test and make you know what's going on. I Think it's a hardware problem.
The first time it happened was in the last summer in August when I was digging in the sea. While I was in the water suddenly my Excalibur did'nt detect so I put it near the metal shovel and nothing comes from the Grey Ghost headphones so I say to myself that something was happened.

 

[sullivan2002]

Ok but if I open one side to see how are the coil wires and juctions, I will also pull out the motherboard.

 

[sullivan2002]

Another video that maybe could help on finding a solution:

[video]https://youtu.be/jSZbrB0pxjs[/video]

 

[Ron from Michigan]

Sullivan, Joe has a lot of experience with the Excalibur hopefully he can help you. Good Luck Ron

 

[sullivan2002]

I know Joe and he helped me a lot. Before opening my Excalibur I need to have more info as possible.
I have some experience on soldering and electronic devices but Minelab Excalibur is not a simple device, it is a water-proof hermetic device and everything must be done with care, otherwise you risk ruining everything. For this reason I'm trying to get as much information as possible not to go random, I think my case is unique because I have not found other similar cases.
Of course I made some tests, now I'm sure it's not a battery problem even though the battery lasts a little and is to be changed, this is because I made tests powering my Excalibur to an external power supply of 13volt. I don't think it's the coil, the coil has no sign of damage on it. Also cable is in good condition. The problems could be the pot, or something inside the box.

 

[Rick(ND)]

What I would do if it was mine if this happened to my detector would try to find out where the problem is by process of elimination . The things I seen on your video is if you turn up the threshold it gets no detection you can hear. Turn it down to normal and it detects, but I feel the threshold is over powering the signal. Now I would start turning the controls and see if you hear any static as one control could need replacing or cleaning. If that seems find then with it working wiggle the coil wire where it goes into the coil and anywhere inbetween the coil and control pod to see if there is any static there or cutting out as the coil wire could be broke. if this all seems OK then see what will happen when it is working and tap on the control pod or moving it upside down and see if this make any difference. One thing you can tell if one item act up is the area I would think the problem is.
Just from the little I seen on you video by turning the threshold up you lost your sound of detection, so I would be looking at this first as why it does this. You also said from what I understand you have a 13 volt power supply hooked up to it, but is it the right amperage to run this detector and turning up the threshold may take more amperage the supply can not produce. The reason I mention this is we have seen over the years where some try to put rechargeable in the Sovereign battery pack and get the low battery alert as there is not enough voltage and I am sure this can go for amperage too. On the low battery alert the threshold will get loud and will not detect a target. The Sovereign and the Excalibur are built the same inside to work the same, so maybe this is something to check out that maybe the battery you have is not good anymore.
Just a few things I was thinking on and hope it can help.


Rick

 

[sullivan2002]

Today I opened my Excalibur and see what's going on inside. I didn't find water inside, no condensation water and the pots seem ok. No bad caps. The tracks are ok. Honestly I did not expect it was so in good shape inside.

well The hypotheses could be:

1. Coil problems. Maybe there is a little broken cable inside

2. Pot damaged inside cause from outside all pots are in good shape

3. Quartz damaged due of a shock or when the box has fallen to the ground

In this case what exact frequency must be this Quartz? and as you know, what happens if a quartz breaks in a metal detector?

with a little oscilloscope bought last month, If I go to test on the quartz heads if there is the sinusoidal signal of the oscillator are you agree if there is no signal, maybe it's broken?

 

[sullivan2002]

I have to check the quartz on the board.
Who knows the value of the frequency?

Does anyone have the electric scheme of the Minelab Excalibur 1000?

 

[LawrencetheMDer]

Haven't read all the replies but my Excal 1000 has wire rot w the battery cable from the battery to control unit. I have removed the cable, found both wires to be cracked and split, and in process of replacing. The 2 wires inside the cable crack and start to short/open. I also believe that the cable from the coil to the control unit, esp the cable near the control unit, also fails. One possible solution is to shorten the coil cable, when you replace the battery cable, and cut out the bad portion of coil wire near where it reaches the control board.

 

[sullivan2002]

Haven't read all the replies but my Excal 1000 has wire rot w the battery cable from the battery to control unit. I have removed the cable, found both wires to be cracked and split, and in process of replacing. The 2 wires inside the cable crack and start to short/open. I also believe that the cable from the coil to the control unit, esp the cable near the control unit, also fails. One possible solution is to shorten the coil cable, when you replace the battery cable, and cut out the bad portion of coil wire near where it reaches the control board.

Sound of Threshold works good, I can increase and decrease it at will.
With a tester voltage is ok to the circuit so no bad power cable in my case. No battery problem cause I used a simple Power supply at 13.8V 5A.

I tried to replace the threshold pot without success, pot are ok

Now I don't konw what to do sincerly.

It remain, the coil, the quartz, and other components.

The strange thing is that now, never detect, at the beginning of this issue as you can see on the videsos: it detect sometimes

[video]https://www.youtube.com/watch?v=o32VoqV-2js[/video]

[video]https://www.youtube.com/watch?v=l5_KrrTV9Dg&t=33s[/video]


Now nothing, only the Threshold sound and nothing else,

I tested the impedance

 

[bklein]

No, not the crystal. Use your scope to see the tx waveform on the coil wires.
I would take it out of the housing and look for a solder open somewhere. Press on things while running it. Put a big metal thing by the coil so once connection is restored it is obvious.

 

[sullivan2002]

No, not the crystal. Use your scope to see the tx waveform on the coil wires.
I would take it out of the housing and look for a solder open somewhere. Press on things while running it. Put a big metal thing by the coil so once connection is restored it is obvious.


Yes, I did
I took it out of the housing two months ago and see the boards, boards are very clean wihtout any water white marks on it, however, I cleaned it with isopropyl alcohol.
When I made all the test, always I put a a large piece of aluminum over the coil of course.

Result at this time is: no water marks on the plates

the 4 capacitors are ok

the 2 inductances at the beginning of the circuit are ok

SOUND is coming to my headphones but it's for the threshold sound

No other sound, no detection

 

[bklein]

Check some things with your scope - verify pots by looking at wipers as you move them. Look at tx and rx wires, what do you see? Just touching the rx wires may change the audio on a good detector (not sure). Verify battery voltage in a few places on the board. - it may be too low due to a weak trace.
You can also get a can of freeze spray and a heat gun and test areas of the board for any change. You have an intermittant you need to find.