AU 20,000 No Power

Voltages with board UNPLUGGED

6 pin :

0v
0v
0v
0v
-69v
0v


10 pin :

0v
0v
0v
0v
-0.1v
0v
-0.08v
+8v
-66v
+66v


PLUGGED :

6 pin :

0
0
0
-7.03
-70
-66.7


10 pin :

-63.1
-66
-64.3
-64.3
-64.7
-64.4
-64.2
-4.4
-65.5
+65.5
 
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Note - 5 wires going from the driver board to the connector board aren’t connected. (Isolated their ends with heat shrink)
Shall I solder them ?
 
Shall I solder them ?
Depends why you disconnected them... but yes do reconnect them.

So what happened to my request for 5 voltage readings? - measured ON the driver board itself if possible. (or as close as possible otherwise).

Like this
Low current regulated voltages +??V & -??V

High current unregulated voltages +??V & -??V

Left channel DC offset (is it + or - ?) ??V - and is this adjustable?

Note that I have never seen an AU-20000 in the flesh - so '10 pin connector' this and '6 pin connector' that means very little to me.
 
Depends why you disconnected them... but yes do reconnect them.

So what happened to my request for 5 voltage readings? - measured ON the driver board itself if possible. (or as close as possible otherwise).

Like this
Low current regulated voltages +??V & -??V

High current unregulated voltages +??V & -??V

Left channel DC offset (is it + or - ?) ??V - and is this adjustable?

Note that I have never seen an AU-20000 in the flesh - so '10 pin connector' this and '6 pin connector' that means very little to me.


To remove the board it’s necessary to unsolder the 5 wires connecting it to the connector board

I plugged it and soldered the wires back to where they were . Made a reading for all voltages at the pins and it’s the same as I posted it in my previous post.

The driver board plugs into 2 types of connectors , one has 6 pins , and the other has 10 pins .
That , in addition to the 5 wires soldered to the board.
I think the supply voltages are the common for both channels - am I right? I see them connected together in the traces for both channels
I checked voltages for the right channel and they are identical to left .
Also , I checked ON BOTH BOARDS the voltages at various places (where I could - it’s not so spacious ) and all places I checked were identical in voltages in both boards .
The left channel ( the one that takes the amp into protection) output transistors aren’t mounted .
 
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I think the supply voltages are the common for both channels - am I right? I see them connected together in the traces for both channels
Well done, that is correct, (for the low current regulated supply). ;)
I checked voltages for the right channel and they are identical to left .
So, these voltages you measured, what are they?.... - it's a secret then? :rolleyes:
 
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High current supply +ve = Collector of OP transistors TR1, TR2, TR5, TR6, TR9, or TR10 - to ground
High current supply -ve = Collector of OP transistors TR3, TR4, TR7, TR8, TR11, or TR12 - to ground

Although the driver boards should have the same voltage readings on BOTH - we need to check that they actually DO have those voltages -
Hence:-
High current supply to driver board +ve = on F-2507 Collector of driver transistors TR8, TR10 (check for both driver boards) - to ground.
High current supply to driver board -ve = on F-2507 Collector of driver transistors TR3, TR11 (check for both driver boards) - to ground.

Low current supply to driver board +ve = on F2507 - junction of R04 (33K) & R12 (330Ω) - to ground. (and the same on the other driver board).
Low current supply to driver board -ve = on F2507 - junction of R06 (10K) & R11 (330Ω) - to ground. (and the same on the other driver board).

DC offset = measure on each F2507 at the junction of R33 & R34 (both 47Ω) - to ground.

I am assuming you will have everything connected & both driver boards installed. If you can't do this because of something overheating or blowing fuses - let me know.
 
High current supply +ve = Collector of OP transistors TR1, TR2, TR5, TR6, TR9, or TR10 - to ground


Right channel (the one that doesn’t get the amp into protection)



Tr01 e-9.2v b-8.6v c-9v

Tr05 e-67v b-66.4v c-67v

Tr06 e-65.4v b-65v c can’t measure (sleeving)

Tr09 e-66.4v b-67v c-67v

Tr10 e-65v b-64.6v c+67v

Tr11 e-66v b-66v c-67v


Never seen so many Negative readings :(


High current supply -ve = Collector of OP transistors TR3, TR4, TR7, TR8, TR11, or TR12 - to ground


Tr03 b-9v e-8.54v c-8.5v

Tr04 b-8.5v e-8v c-64v

Tr07 b-65v e-65v c-67v

Tr08 b-64v e-64.6v c+67v

Tr11 b-66.6v e-66 c-67v

Tr12 doesn’t exist .



Low current supply to driver board +ve = on F2507 - junction of R04 (33K) & R12 (330Ω) - to ground. (and the same on the other driver board).


Right board -5.5v


Low current supply to driver board -ve = on F2507 - junction of R06 (10K) & R11 (330Ω) - to ground. (and the same on the other driver board).


R06 -70v & -23.1v

R11 -70v & -68v


DC offset = measure on each F2507 at the junction of R33 & R34 (both 47Ω) - to ground.


Right board -65v

I checked the right channel only because I must remove it to get a safe access to the other board. Please let me know if you want me to make more readings on the right board before I remove it and what do you think so far?
Thanks
 
High current supply +ve = Collector of OP transistors TR1, TR2, TR5, TR6, TR9, or TR10 - to ground


Right channel (the one that doesn’t get the amp into protection)



Tr01 e-9.2v b-8.6v c-9v

Tr05 e-67v b-66.4v c-67v

Tr06 e-65.4v b-65v c can’t measure (sleeving)

Tr09 e-66.4v b-67v c-67v

Tr10 e-65v b-64.6v c+67v

Tr11 e-66v b-66v c-67v


Never seen so many Negative readings :(


High current supply -ve = Collector of OP transistors TR3, TR4, TR7, TR8, TR11, or TR12 - to ground


Tr03 b-9v e-8.54v c-8.5v

Tr04 b-8.5v e-8v c-64v

Tr07 b-65v e-65v c-67v

Tr08 b-64v e-64.6v c+67v

Tr11 b-66.6v e-66 c-67v

Tr12 doesn’t exist .



Low current supply to driver board +ve = on F2507 - junction of R04 (33K) & R12 (330Ω) - to ground. (and the same on the other driver board).


Right board -5.5v


Low current supply to driver board -ve = on F2507 - junction of R06 (10K) & R11 (330Ω) - to ground. (and the same on the other driver board).


R06 -70v & -23.1v

R11 -70v & -68v


DC offset = measure on each F2507 at the junction of R33 & R34 (both 47Ω) - to ground.


Right board -65v

I checked the right channel only because I must remove it to get a safe access to the other board. Please let me know if you want me to make more readings on the right board before I remove it and what do you think so far?
Thanks
I know it's an old thread, but don't you just hate it when the story stops before the end?
Was the thread moved ?
Would have loved to read what was wrong...
 
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