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Panasonic stereo no power

Steeve

May 8, 2020
1
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Hi ,is there anybody who can help me with my Panasonic SA-MAX 770 stereo? I’ve got no power on. Checked the power cord fuse , burnt caps and checked the bridge on board. Seems good. Don’t know what to do further??? Help please
 

Martaine2005

May 12, 2015
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You may have checked them, but tell us how you checked them.

Did your check also include VOLTAGE checks?. What were they?.

Martin
 

73's de Edd

Aug 21, 2015
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Sir Steeve . . . . .

Wearing your BIG BOY pants ? . . . . if not better leave now, and go get them, and also grab your 3 in wide suspenders with their 12 grip clips and a HEAVY belt . . . ALSO . . . . might as well make it your pole linemans belt . . . .cause you're gonna need them on this task.

I skimped with the mini sizing of the PCB foil layout, just considering that it will only be used to let you initially find your way thru the jungle in the boards parts locations.

Of your initial interest will be the A-B9 corner where the RED oval is the AC line power entering the set, it has to pass thru two GOOD fuses at the YELLOW boxed points until you get up to the F-G 10 sector where AC is rectified to make raw DC power at C1403 E-cap.
Confirm that raw B+ is being there after a power up of the set . . . . actually by just a plugging in of the set to AC power.
Since, this PARTICULAR power supply section is basically being the "pilot light flame " of this " furnace ".
If you have raw DC voltage across C1403 there . . . . and I don't know if you are using Amerikanski or You-are-a-peeing AC line voltage . . . . . if being the latter, 340-350 'ish volts .
Then look to the inner chassis side of C1403 for the YELLOW boxed 8 pin IC1402 and give particular attention to its pin 5 corner to see if there is a hole burnt into that corner of the case or if the case might be split or have a corner blown off from it .
If physically appearing O.K., then find the two BLUE marked up E-capacitors that your 3.3 VDC is being stored in and confirm that voltage presence.

If all is well so far, then see if the set will power up and then you move over to C-1 corner sector and its connector CN1851 there and use meter DC ground referencing as connector pins 6-11 or 12.
And only confirm the 15VDC and 3.3 VDC supplies presence .
That connector schema snippet is shown at right bottom corner of page . . . PINK boxed.

Waiting to see how it goes for you . . . . . .

Le PUNYSONIC Schematique . . . . . .

Panasonic-SA-MAX-370-770-PU.png





73's de Edd . . . . .


Did you hear about the kidnapping at school?
Oh h h h h . . . . it's all okay now, he woke up.


.
 
Last edited:

Amraks

Jan 28, 2012
6
Joined
Jan 28, 2012
Messages
6
I know this a old thread
Sir Steeve . . . . .

Wearing your BIG BOY pants ? . . . . if not better leave now, and go get them, and also grab your 3 in wide suspenders with their 12 grip clips and a HEAVY belt . . . ALSO . . . . might as well make it your pole linemans belt . . . .cause you're gonna need them on this task.

I skimped with the mini sizing of the PCB foil layout, just considering that it will only be used to let you initially find your way thru the jungle in the boards parts locations.

Of your initial interest will be the A-B9 corner where the RED oval is the AC line power entering the set, it has to pass thru two GOOD fuses at the YELLOW boxed points until you get up to the F-G 10 sector where AC is rectified to make raw DC power at C1403 E-cap.
Confirm that raw B+ is being there after a power up of the set . . . . actually by just a plugging in of the set to AC power.
Since, this PARTICULAR power supply section is basically being the "pilot light flame " of this " furnace ".
If you have raw DC voltage across C1403 there . . . . and I don't know if you are using Amerikanski or You-are-a-peeing AC line voltage . . . . . if being the latter, 340-350 'ish volts .
Then look to the inner chassis side of C1403 for the YELLOW boxed 8 pin IC1402 and give particular attention to its pin 5 corner to see if there is a hole burnt into that corner of the case or if the case might be split or have a corner blown off from it .
If physically appearing O.K., then find the two BLUE marked up E-capacitors that your 3.3 VDC is being stored in and confirm that voltage presence.

If all is well so far, then see if the set will power up and then you move over to C-1 corner sector and its connector CN1851 there and use meter DC ground referencing as connector pins 6-11 or 12.
And only confirm the 15VDC and 3.3 VDC supplies presence .
That connector schema snippet is shown at right bottom corner of page . . . PINK boxed.

Waiting to see how it goes for you . . . . . .

Le PUNYSONIC Schematique . . . . . .

Panasonic-SA-MAX-370-770-PU.png





73's de Edd . . . . .


Did you hear about the kidnapping at school?
Oh h h h h . . . . it's all okay now, he woke up.


.
I know this is 2 years old this thread.

I have followed steps for voltages on this amplifier
1851 is missing its 15v on 10 & 9.
1851 has 3.3v on pin 7

what would be our next steps?
 

Bluejets

Oct 5, 2014
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Above schematic will not zoom in enough to make out any detail.
 

Bluejets

Oct 5, 2014
6,901
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Oct 5, 2014
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I'd say you didn't even look at this before you posted it.

Reason is.....no schematic.
Try again.
 

Bluejets

Oct 5, 2014
6,901
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Oct 5, 2014
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6,901
Nope...no deal any of us are going to visit way out sites.... sorry.
 

Amraks

Jan 28, 2012
6
Joined
Jan 28, 2012
Messages
6
I have measured resistance to ground on the 15v rail as well and all that seems normal.
 
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