Minelab Sovereign faulty

[Stefano]

Hi all.
I own a ML sovereign that after a hard drop (2m high) is not working anymore.
I suspect the problem to be the crystal, since this is the only fragile part while the cards are made in SMT and I don't see any wire broken.
May this be correct? I haven't had time to check with oscilloscope if it is oscillating or not, but if that is the case, where can I get a 3.904 MHz quartz? I don't think it is a common frequency...

Thanks

Stefano

[putrechigi]

ciao

ciao stefano sono manolo piacere di averti su questo forum da dove dgt?

[Stefano]

Ciao Manolo.

Romagna.

[Stefano]

Solved

Well, just for everyone's information...
I was lucky. The quartz wasn't faulty (otherwise I wouldn't have had no chance to fix it, because I didn't find it anywhere with that frequency).
It was simply the main switch inside the volume potentiometre that, when turned on, short circuited the +bat to the ground.

Thanks anyway.

[Unregistered]

bbNWFH

Timing Sovereign GT. http://www.md4u.ru/forum/viewtopic.p...cb9f1eee#34282
Regards.
Vladimir D.

[Sean_Goddard]

A 4.0MHz will do. Minelab (scumbags) stole this mod off me and added it to the GT, it's called noise cancel. All this mod if "theirs" does is change the CPU frequency by electronically swappping the crystals (check, there are 2 in a GT, one in a Sov XS, and hence the Tx frequencie(s) and hit reset to make it all go again).

This mod also help with ground balance and depth as the CPU is processing the data a litle faster. I've run some up to 5MHz. basially you are overclocking the CPU. Some work, some are OK then die after a few months. THAT'S why Minleab had so many problems with the GT, but they're not clever enough to work out how to get around the problem, and I'm not going to tell them .

[wam]

Sovereign faulty Q7

Hi, I have faulty Minelab Sovereign early model Rev1.1.
I can see that transistor Q7 is carbonaited. Can any one check for me what Q7 type is?
I may replace U24 next to it as well . I think U24 is TE0620N but it could be T*062*N.
One more is C32 I can only expect that it was 22uF16V like C31 next to it.
If some one can confirm it, please.
Regards,

[wam]

I found one more problem (I hope it will be the last).
I have carbonated transistor Q1 on switches PCB as well.
Please, if some one can help what type it was.

[Altra]

Hi Wam
Both appear to be BST70A. N channel fets. Looking at the face Drain,Gate,Source

http://www.nxp.com/acrobat_download2...T70A_CNV_2.pdf

The BS170(best) and 2N7000 would work if you can't find the BST70A. The 2N7000 the drain and source are reversed so you would solder it reversed to the silkscreen.

The cap is a 22uf/16v tant. D1, Q7 and the TL062 form a 10V regulator

Good luck
Mark

[wam]

Thank You a lot. I have 2N7000.
I have checked data for BST70A (D-MOS, 80V, 0.5A, 2R, 300ms)
But I have stronger transistors as well.
IRFU014 (MOSFET 25W 60V, 0.2R 7A, 150C)
RFD16N05 (MOSFET 60W 50V 0.047R, 16A 175C)
IRFU320 (MOSFET 42W 400V 1.8R 3.1A 150C) )
I am ready to use IRFU320 type "MOSFET" but original BST70A is "D-MOS".
I am not sure if it can be done this way.
May I ask Your opinion?
Regards.

[Altra]

I would be careful replaceing the low current original, with a 6 amp power fet.
Those parts burned because something is shorted. They saved the rest of the circuit
by acting like fuses. A power fet will just get hot while something else on the board melts if the original short still exist! Try your 2N7000 first to get it going. JMHO

[wam]

Just to say THANK YOU,
Before soldering 2N7000 I have found that one of the large electrolitic caps has only one leg solder to PCB (the other leg was broken). I believe it could be due to impact - I decided to secure new capas with silicon, not sure but broken cap could damage 2N7000. Now all works OK. Verry happy.
I have nature to eksperyment so temptation is to connect to it 18kHz coil for "gold" or 6 khz coil for relics. Did any one try to do it or know that it is safe to do and if software can detect with narow frequency coils ?
Regards,

[Altra]

Wam, Thats great!

The Sovereign coils have a pre-amp in them. So you can't just put any coil
on. Do a search of the forum and you will find photos of the amp and some home made
coils.

Mark

[Alexismex]

Hello Forum.
with little knowledge in electronic .... my thinking is what happen? in those minelab detector that they carbonized...fried.... their components !!!!!!!!!!! not so very good electronic design .......never see that in Eric foster equipment , see white detector ........
What do you think???
Alexis

[wam]

A 4.0MHz will do. Minelab (scumbags) stole this mod off me and added it to the GT, it's called noise cancel.

Hi, can You say what crystal frequences are used in GT and if GT software is the same like original Sovereign? I do not get it why 2 x crystals - timing can be changed in the software with one crystal.
Regards