Jeohunter - Visual Ground Scanner

[geo-i]

thanks you my friend

hello my friend fun finder thanks you so much again
you are the friend i will try to very carefully the best
i can thanks for all my friend.


regards
geo-i

[geo-i]

for all answer

hello sir Qiaozhi each human being had made a mistake i am responible for the all answer i will try to change my mistake sir thanks.



regards
geo-i

[Funfinder]

Workaround update and precautions!

Hi geo-i

thx for your kind words and that you you're so tough in
such a frustrating situation. Also my respect that you
wanna try to repair it and I have a good feeling that
you could make the Jeohunter work again.

And Thank you bro for the new very good makro pictures!



Before you start some additional precautions:



- if you think the soldering pins are to tiny
for you better find some with good soldering skills!
(or buy a soldering iron with a very small tip)

But if you work cautious by the method I have
described (soldering tin only at the wire-contacts,
holding wire onto the marked point and heat wire with
soldering iron until metal melts and creates connection)
you should have no problems.


- be very careful at the C4 spot (see picture - dot of the "!")
here you must try to solder as short as possible
because otherwise to much heat will destroy the C4
(this is a very small capacitor, surface mount device and
we don't have the value, so we can't replace it)
But the marked spot for soldering at the left side of C4
is pretty "large" so you should make it.
Just try to solder as short as possible at this location!



- you can find the replacement resistors in old
electronic stuff like broken TVs, VCRs, radios etc.
All you need is a pliers to break them carefully off
(plug of mains and be careful if you disassemble TVs,
those can contain loaded high voltage capacitors...)

The color codes of the needed resistors are:
--------------------------------------------------
51k resistor: green-brown-orange-gold (or silver)
(or gold-orange-brown-green if you hold it reversed)

5.1k resistor: green-brown-red-gold (or silver instead of gold)
(or gold-red-brown-green if you hold it reversed)

If you don't find them you could try to use a resistor
that is very close to the given values:
for the 51k R. from 45k to 55k)
for the 5.1k R. from 4.5k to 5.5k)

pleas google for resistor color codes and how to use them.

- try to clean or carefully remove the burned area
of U1 to avoid shortcuts form there
but I hope it will work without it, because
if the IC is burned there is no more dangerous
connection inside of this digital potentiometer
(a potentiometer is just a variable resistor)


! geo-i, perhaps you can call yourself really lucky
that only replacable parts got burned!
Let's hope nothing else has been damaged!
If nothing else was destroyed the chances are
really good that our workaround will work!

But this time you really have to do it PERFECT !!!
Good luck and take good care!

[geo-i]

thanks

hello my best friend funfinder thanks again for everthing for all
infomation that you give to me i soon hope the matter will
back to normal way and for you i wish susccssful work will
continu and for all geotech fourm thanks bro.



regards

geo-i

[Funfinder]

Allright, geo-i, and keep me informed
what you want to do now and when you
have the time for it so I can coordinate
my support.

The most important and first thing is
that your accu-pack will work correct
like it was before.

And for the digital potentiometer replacement
you should collect a bunch of different resistors
and find a variable resistor with 50k - 100k Ohm.

Let's hope you'll get back a working Jeohunter soon.

[syed ayub basha]

Sir you modifies all this for what purpose, tell me.

[geo-i]

understand

hello my friend syed ayub basha do you
read each question at the geotech fourm
if you already understand it very good.
everyone needs help when in trouble
bro. thanks


regards

geo-i

[geo-i]

concentrate and focused

hello my friend fun finder i think now i want to concentrate
and focused on my circuit board and i had stop tresure
hunting and i am searching for radio and vch waste to use
bro, on digital u1 potentionmeter fit i have to change or
do not use it agin? thanks


regards
geo-i

[Funfinder]

@ syed ayub basha

> Sir you modifies all this for what purpose, tell me.

Improvements and technical development!

As example your Jeohunter 3D now has
"reset button mod" as a standard feature.
If you have more experience, it is very easy
to check with it even at high sensitivity if its a
real hit or the cause of ground mineralization etc.

btw. at some big US MD-shop (shipping worldwide)
I found the attached below info about cavity-detection:

http://www.metaldetector.com/makro-j...metal-detector

[Funfinder]

Hi geo-i,

it is very good that you're looking for the parts now.

You can use 47kOhm and 4.7kOhm resistors instead
of the 51k / 5,1k and you can see them on the picture.

But if you find those 51k and 5.1k resistors it's also OK.

You cannot replace the digital potentiometer on your own
but you may find analog resistors / potis (also see below).

Sometimes those are used to turn the radio's volume up
and if everything works you could attach one of those big
potis to the Jeohunter box and adjust it from the outside.

btw. forget about "only 50k-100k variable resistors" -
simply look what you can get and if needed you can
solder another resistor in series to the variable one.

Good luck @ the electronical parts treasure hunt.

[Funfinder]

reset button & cavity info

@ syed ayub basha

This is from the Jeohunter instructions manual
you can download from the above page as pdf.

[geo-i]

replacement of resistors

hello friend fun finder how are you bro.
I did replace the 2 mount resistors from the broken radio
and I also have and analog resistors should I remove it half
of the U1 at the left side or remove it all .
let make it clear to me ,regarding the 2 resistors I replace it
new one should I solder back with the 51k that you mention
and please show me how to install the analog resistors so I
can straight forwad installed. thanks


regards

geo-i

[Funfinder]

Hi geo-i,

thanx for asking, I'm fine, successfully finished the little
LCD-TV project - now I can watch composite in (SCART)
and the needed power directly comes from the batteries.

accu-light longtime test is done, too:
the lamp shines continuously (is this greek language? )
for over 250 hours !!!!


It would work even longer but after 250h the li-ion accus
are down at 3V and for safety it's better to keep this limit.

I hope you also have a good time, geo-i!



Congratulation, you soldered very well the SMD resistors.

> should I solder back with the 51k that you mention?

No, your already soldered mini-resistors are fine,
as long as they haven't been damaged.



But what have you done at C4 - this is a possible shortcut!
Why you do such things if the advice tells it clearly different?

Perhaps such contact is OK after many tests, if it's shure this
connection is capable for full power, but absolutly not yet.


btw. always be careful creating no electrostatic charges
while working at the mainboard - it contains sensitive
computer etc. parts!

And have you checked the vertical circuit board
that everything's OK there?

Your accu-pack really has the correct voltage and polarity?


If yes and after you have soldered the 20cm long and
of course isolated wires at the described position you
can reassemble the Jeohunter but you can leave the
box still open.



Don't remove the U1!



Attach all the cables as shown in the diagram some posts
earlier. Don't confuse them and plug them with correct
polarity (check the color dots at the diagram!)


----------------

If everything is done we have to identify the value
of the variable resistors AND/OR you need to solder
some 500 Ohm resistor in line for safety.

And check out which contacts of the variable resistors
are the variable ones. If there are three contacts mostly
this is one outside and the one in the middle.

---------------

Good luck but don't try any new "experiments"!

[syed ayub basha]

Hello sir funfinder In analysis Report

Mineral Effect,
Frequency effect,
Electric effect,
Magnetic Effect,
Mix Effect,
Carbon Effect,
All this shown, what is the meaning of all these. can you explain detail. after your explanation, any thing i cont understand i will ask you. now i don't know any thing about all these. please sir guide me.

[geo-i]

explain

hello my friend sorry about the shortcut my be I not fully
attention to the answer you give because health not well today
bro sorry my friend . about the volt and the polarity it is correct
same the joehunters accu pack bro ,what do you mean vertical
circuit can you explain to me thanks .


regards

geo-i