Garrett Treasure Ace 300

[ivconic]

Low drop voltage regulator part...

[kt315]

give a link...
http://metadec.narod.ru/sch_md/ACE_sch.gif
ACE-250 is more later one... can compare...

[ivconic]

Yes i know, i saw it before. Yes, there are some simillarities.
Ace 250 is from new serie and my Ace 300 is from old serie, discontinued.
At Ace 250 i see LMCP6035 while at Ace 300 there are LMC662 instead.
Also what's very interesting (on Ace 250) is LM386 at output!??!
I intend to use this coil, so now i am reconsidering to trace this pcb and form schematic and later to make some changed handmade for use with this coil. Coil is Crosfire II (~22cm)..

[ivconic]

Ehh! Like usuall - i made mistake in schematic. Transistor at TX is PNP not NPN..!

P.S.
I dont know what happened!?!? I tried to edit previous post with mistake on schematic and to replace with this one. But than i got message that 60 minutes for editing post was expired....and so i posted this post here. But than i see that schematic from not edited post disappeared somehow!? Ahhahahahahaah! Never mind! Even better! Ok...this schematic is proper now!

[Qiaozhi]

What happens if you connect the 78L05 but leave the output pin disconnected? Is there 5V at the output? If it measures ok then do a continuity check between the PCB track (that should be connected to the regulator output) and 0V line. Is there a short there, or very low resistance?

[ivconic]

What happens if you connect the 78L05 but leave the output pin disconnected? Is there 5V at the output? If it measures ok then do a continuity check between the PCB track (that should be connected to the regulator output) and 0V line. Is there a short there, or very low resistance?

Yes than output is some 5.15v or so.
Yes i thought so too. But...hmm...many components left on pcb. I performed detailed eye check using loupe, haven't spotted anything bad.
I can perform continuity check between +5V track and 0V line tomorrow and see.
Really funny situation. I would never beleive that uPc is burned. Those things usually do not happen at such low power and low voltage devices...but..almost everything checked!? I stucked nowhere!

[Qiaozhi]

Yes than output is some 5.15v or so.
Yes i thought so too. But...hmm...many components left on pcb. I performed detailed eye check using loupe, haven't spotted anything bad.
I can perform continuity check between +5V track and 0V line tomorrow and see.
Really funny situation. I would never beleive that uPc is burned. Those things usually do not happen at such low power and low voltage devices...but..almost everything checked!? I stucked nowhere!

I would guess that there's a short on the +5V power rail. If someone has already attempted a repair then it could be a solder bridge or a component inserted incorrectly.

[ivconic]

I am going now to give a last chance to that uPc! Will report what was done today evening!
I am sharp and dangerous now! ()

[Qiaozhi]

I am going now to give a last chance to that uPc! Will report what was done today evening!
I am sharp and dangerous now! ()

Lock up the hammer ... just in case.

[ivconic]

It was uPc finally!
All the components removed from pcb except uPc. Resistance (you suggested) between +5V and - rail is 18 ohms!
Finally uPc removed from pcb and no problems (short or resistances) between those rails. So...uPc! How? Can't tell. Most probably previous "servicer" played with extended power supply and burned uPc.

Mentioning hammer..ha! Hammer is locked but grinder is not! Since i dont have proper soldering gun (hot air) just ordinary Weller, i used grinder to remove "gently" uPc from pcb intending to preserve only pcb for further works!
I also removed a piece of my finger too!
Don't nobody tells me it is easy job..this electronics! I invested my blood into it!
Ok... today i will prepare complete schematic with component values and hopefully post it here soon..

[ivconic]

Here is schematic. Checked.
I am not sure only about that "J112" Motorola component. Is it fet? Looks like.
Although smt case is a bit different than usuall presented in datasheet. Also pin assingments are unknown to me. Looking at nearest datasheet i am a bit confused. Looks like batt.2 goes to G and signal from uPc to D, speaker to S...
Is it correct? Anybody can justify this?

[ivconic]

ExpressSCH file...

[ivconic]

This should be equivalent to that fet stage, although i am not sure. Looking at datasheet from various manufacturers i am more confused!
Scrabble games and simillar...
Some components came from Motorola are oftenly out of any standard! Most of those i void to use just because dont have proper and accurate pin assignments...already had same problems in the past, much!

ITT, Siemens, Philips - RULE !!!

[nakky]

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[ivconic]

Oh yes! I forgot to say that original fet is blowed already...shorts in all directions, that's why i can not distinguish it with multimeters...
However....it is not important at all, it is just an ordinary audio. Any other can be used here.
First coming to my mind is simillar audio output from White's Eagle Spectrum!