Problem with Tesoror Sandshark

[joejoe]

Hi all, long time no see, nice to see everyone still kicking.
I have a problem with my sandshark, it's giving me these nervous dog pulsing sounds, or lady-in-labor pulsing sounds, lower and higher when it is not moving, worse when moving. It didn't do that before, it seemed to operate fine until the last time I took it out to locate an old wreck when it seemed everything was a target. It registers metal, but I can\t tell the difference when there is and isn't.
Messing with the threshold and f switches doesn't affect anything for the better. It is a hardwired unit, I was thinking of washing it out with alcohol in case of of moisture but haven't done anything as of yet, thought I'd ask the experts first before hitting things with the trusty hammer.
Batteries are fresh, the manual said to be careful of loose wires, though that doesn't seem to be the problem, tied 'em down with no wiggle and no difference, huhhuhuhHUHhuhhuhHUHhuh or eeeeEEEEEEEeeeeeEEEEEEeeeeeeeeee... you get the idea.
Any tips before I try to send it back to the old USA would be a great help. Thanks.

[kt315]

hello, can you share some pics inside the block?

thanks

[joejoe]

Yes, I'm sure that I can, except, what is the block? The circuit board doesn't seem to want to come out that easily, appears to be attached to the coil cable on the inside and only moves so much. In any case I'll take a snap of what I can. I'll be back.

[kt315]

ok. I meant the housing and pics of PCB both side, pots, face panel. at sunny day, at open air, if possibly. after, I can repeat to upload Carl's schematic, if you need in it.

[joejoe]

Ok, this is the third time I try to send the photos, seem to be having trouble. I'll do one and then try again for the others.

[kt315]

my email address [email protected]

thank you in advance

[Carl-NC]

Sounds like the coil shielding may have broken loose. If you take the PCB out of the control box, try disconnecting the coil and see if the problem goes away.

[joejoe]

Ok. I unclipped the coil wires and the sound has stopped. It was still some erratic sound when I first took off the black wire, then all quiet when the positive came off. There was some corrosion on the solder where the coil wire attached to the pcb, but nothing too nasty, kt315 has an image of it.
My feeling was it may have something to do with the joining at the coil itself, wiggling it around before I unclipped it seemed to make it cry worse, though it could have been coincidence.

[kt315]

Joe, thank you for pic you sent. I have to give warning you - do not power on without the coil. anotherway you may use small selfmade coil, with ferrous corn, L=300-400 uH.
you can cut some lendth from the cable, 4-6 cm enought, from housing side, then cut it along. you'll see cable state and shielding wires' state.

[joejoe]

Thanks for the advice, I was wondering what to do after cutting it up with the scissors. Too bad I didn't know about the powering up, did it, connected, disconnected, several times and even knocked around the metal tower on the center of the pcb, which would then make a sound similar to what it was doing when it was acting erratic. Though I think it still works.
I have a couple homemade coils for my tdi, can I use these on the pcb of the sandshark?
When I cut the wire, what should I be looking for?

[joejoe]

Ok, I removed a few inches of the coil wire, looks to be in pristine condition, shiny with no frays.

[Carl-NC]

Running it without the coil shouldn't hurt anything.

[joejoe]

Thanks Carl, I was slightly worried, it would not have been the first time ruining something.
Kt, did you receive the photos? I took off the (waterproof?)plug at the coil itself and stuck my tongue in there-tastes like a pretzel, very salty. Could that affect the functionality? And if so, can I cut the coil along where it looks like they they sealed it to get into the insides to do whatever it is I might have to do to fix it?
Hmm... this is beginning to get interesting. Thanks to you both for helping me.

[kt315]

Derek, seems you are minimalist =) all pics are so very small to see anything. try use http://tinypic.com/#!
or similar something. I am not in course what good sites in english there are for the uploading, I use the sites in russian.
I hope people will give the links. can you upload full size pics of both side of the pcb? tia

[joejoe]

Well, it might be a little while to try to send a high resolution pic, my internet is so slow as to go backwards in time. One thing I was thinking was to find another coil before a friend comes down and give him. They once found a wreck that had blocks of brass, supposedly there might still be some. I also just picked up a tf-900 with the cave mode, cause where I live, sometimes they bury more than just gold. Plastic buckets with cash, these days. Muhahaha.
Well see, the wife is not so sure. I hope it works in my conditions.
Anyone have a coil for the sandshark lying around?
Thanks, Derek