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jts1957
Joined: 24 Nov 2008 Posts: 2476 Location: Far, Far Away
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Posted: Fri Oct 23, 2015 7:51 am Post subject: |
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I put a new diode in D31 and everything connected. CN2 WAS UNPLUGGED - right?
I unscrewed the board and tested from the underside? seemed the only way to get to the different parts If any circuitry on the board relies on any metal eyelets or shiny foils that the screws would normally secure tightly to the chassis, might pose problematic.
Black meter lead was on each capacitors negative pin for all readings except C41 & C11 where it would be on the positive pin? _________________ You're over there, I'm over here. |
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larserik
Joined: 19 Oct 2015 Posts: 20 Location: Australia, QLD
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Posted: Fri Oct 23, 2015 10:12 pm Post subject: |
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jts1957 wrote: |
I put a new diode in D31 and everything connected. CN2 WAS UNPLUGGED - right?
I unscrewed the board and tested from the underside? seemed the only way to get to the different parts If any circuitry on the board relies on any metal eyelets or shiny foils that the screws would normally secure tightly to the chassis, might pose problematic.
Black meter lead was on each capacitors negative pin for all readings except C41 & C11 where it would be on the positive pin? |
Ok i went and redone it, think I did a few things wrong 1st go.
Black meter lead was on each capacitors negative pin for all readings except C41 & C11 where it would be on the positive pin?
(I did this on this test, I didn't do this 1st go.)
This was with CN2 disconnected
I earthed the board as you were right there was the 2 corners that relied on earth from the screw. So i earthed those 2 points (and checked they were earthed)
C92= It would test at 345v, it tested this a few times, I kept the meter on it it would drop all the way to .36v then straight back to 345v It did this a few times.
C41= -22.6v
C1= 29.9v
C81= 12.81v
C11= -50.5v
C31= 0V
C51= 6.11v
C71= 5.65v
I checked these all a few times with the same results.
Tried to get the switched voltages, but it would not start.[/b] _________________ .. |
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larserik
Joined: 19 Oct 2015 Posts: 20 Location: Australia, QLD
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Posted: Fri Oct 23, 2015 10:19 pm Post subject: |
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I went and retested C92 then and it seemed to hover around 50v this time? _________________ .. |
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jts1957
Joined: 24 Nov 2008 Posts: 2476 Location: Far, Far Away
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Posted: Fri Oct 23, 2015 11:41 pm Post subject: |
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As long as power is being applied ALL 8 Capacitors WILL have voltages on them.
IF there is NO voltage on C31, recheck that D31 is good (you said it smoked) and in circuit. This time I want you to remove U31 before reapplying power. _________________ You're over there, I'm over here. |
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larserik
Joined: 19 Oct 2015 Posts: 20 Location: Australia, QLD
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Posted: Sat Oct 24, 2015 3:54 am Post subject: |
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Replaced D31 with a new one it was dead.
Removed U31
CN2 Unplugged
Standby.
C92= 1.1-1.3v
C41= -14.15v
C1= 14.4v
C81= 4.7v
C11= -31.8v
C31= 14.65v
C51= 5.5v
C71= 5.66v
switched/on
I could only test for a short time before it would display protect and shut off again.
C92= 35v
C41= -14v
C1= 7v Kept going up and down by 1v
C81= 4v
C11= -34v
C31= 15.83v
C51= 5.56v
C71= 5.67v _________________ .. |
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jts1957
Joined: 24 Nov 2008 Posts: 2476 Location: Far, Far Away
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Posted: Sat Oct 24, 2015 12:28 pm Post subject: |
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Put your meter on diode test and with one lead on pin 3 measure to pin 1, then pin 2. You can then redo with leads reversed.
Also, see if disconnecting L91 from the circuit stabilizes C92 voltage. _________________ You're over there, I'm over here. |
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larserik
Joined: 19 Oct 2015 Posts: 20 Location: Australia, QLD
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Posted: Sat Oct 24, 2015 9:10 pm Post subject: |
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Ok 1st things 1st I may have miss lead you on the last test
those High voltages may have been Mv I not V I didn't see it M displayed so not sure if It was actually 345mv. Sorry
I retested C92 with L91 removed
SB
C92=.6Mv
Switched/run
C92 =34.97V Until protect and shut off.
Results for pins.
Pin 1=.577 Pin 2= .572
Leads switched
Pin 1=O/L Pin 2=.824 _________________ .. |
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larserik
Joined: 19 Oct 2015 Posts: 20 Location: Australia, QLD
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Posted: Sat Oct 24, 2015 10:32 pm Post subject: |
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I just rechecked C92 with L91 installed again to see and yes it was Mv not V I'm sorry.
The voltages are the same.
C92=300mv in SB
C92=34.97v swithched/run until protect shut down. _________________ .. |
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jts1957
Joined: 24 Nov 2008 Posts: 2476 Location: Far, Far Away
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Posted: Sun Oct 25, 2015 4:52 pm Post subject: |
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RESISTANCE across C32?
Resistance on Pin 9 of CN2 the WIRE that connects to AMP connector J3 (NOT SMPS)? _________________ You're over there, I'm over here. |
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Posted: Sun Oct 25, 2015 8:29 pm Post subject: |
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jts1957 wrote: |
RESISTANCE across C32?
Resistance on Pin 9 of CN2 the WIRE that connects to AMP connector J3 (NOT SMPS)? |
I understand the 1st one C32.
Just wanted to check so I'm testing the right thing.
The 2nd test you want me to test the resistance of the 9 wire connector, From pin 9 to the other end of the wire at the J3 connector on the amp board, Does it need to be plugged into the board at both ends to test the resistance?
Thanks |
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