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Ok thanks! i just got home. I see that one photo shows R9 & R100 circled and the other photo shows R99 & R100 circled. Do i also check R99 for voltage?
73's de Edd
- Aug 21, 2015
- 3,640
- Joined
- Aug 21, 2015
- Messages
- 3,640
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Sir Rick79 . . . . . . .
With your progress so far . . . looks like an amp with a high DC presence or imbalance on its output line is not being there . . . . what with all of your monitored DC outputs being way down in the sub 200 MV ranges.
What I suspicion is that the problem is in the section which I have prepped up referencing for you below.
Let me know if your unit is NOT using that 8 pin LM393 dual amp DIP, as another schematic shows there not being one . . . on one schematics revision.
This board is the collection point of sense and fault samplings from all of the power amp boards.
This board has the timed circuitry that gives a gradual power on to the power supply section via a
relay switched AC line thermistor.
Mutes the amps until ready to operate.
Drives your BLUE display LED's as well as the RED -GREEN power status LED's.
And finally, your area of interest, which is the Power amps sense and fault detection circuitry.
When you were checking back at the amps points of that <200MV DC presence, those are points that feed almost directly into a speaker.
Bad news if one of those output transistors shorts and puts either a full 56 plus or 56 minus volts to your speaker, or if there is a gradual change and that voltages starts gradually shifting up to that great of a value.
The sense circuitry would catch that transition quite rapidly and disconnect.
In actuality three factors are checked :
1 . . . . . No excess DC voltage level is on the line which feeds your speaker.
2 . . . . . No excess current is pulled by the power output transistors
3 . . . . . No excess audio power level gets to your speaker.
There is being an inset of one power amp section included in the bottom right corner of the info.
Herewith . . . a synopsis of your Harmonious Cardigan . . . . Autograph 2.2 . . . .resplendently compleat . . . .with its modus operandi explained for the section where I suspicion your trouble to be.
Referring to the power amp inset you will see the RED ARROW path that is sampling the juncture of the emitter resistors of the power output transistors.
When all is well in one or all of these amps, that juncture stays right at a VERY VERY low DC voltage , all of the audios wild voltage swings are occurring up at the collectors of the output transistors, in their replicating of the incoming audio wave forms.
If it is a DC voltage of high enough level to be a problem, it will be carried to the AMP reference RED ARROW input and get diode steered to the base of Q2.
If that level amplitude triggers Q2 into conduction its collector and its load resistor engages section 2 of the U2 556 dual section integrated circuit .
The output of section 2 of the 556 feeds pin 2 of U1A comparator, referencing against a voltage threshold set at its pin 3. Exceeding that reference lets the pin 1 of that comparator flip to a positive voltage which routes down to Q4 transistor .
With Q4's base drive level being met, it fully conducts and thereby robs the base drive from Q8 transistor which has been the relay driver for K1 relay which has been holding and responsible for the system power presence up to this point in time .
With it now disabled your protection engagement is accomplished.
With your low voltages . . . . we best look elsewhere.
Lets take the GREEN ARROW path this time.
Over at the power amps emitter circuitry you will see the tie in of all of the components in the SHADED GREEN area.
Here the circuitry is sampling between the top R57 emitter resistor and the R58 bottom emitter resistor.
The monitored voltage will be a reflection of the current passing through the pair.
As power increases the developed voltage sampled at R74 passes over to the C33 100 ufd capacitor and then that built up voltage ends up at the base of Q31, there is not an immediate response since the C33 time constant of charging up dampens any FAST response to change, with that response time constant being "fine tuned" a bit shorter by that 47 K shunting it.
Once that Q31 base turn on has it conducting, a fault condition is met and carried to the control board via the GREEN ARROW path.
D10 steering diode is isolating 4 other amps, simultaneously connected into this shared FAULT line.
Back at the control board, Q2 gets involved in producing the same protection activation scheme.
Lastly, what might be the most likely of the faults, and that would be the audio output level.
Considering that you are working up to the point where you encounter a protection circuit engagement.
That level just happens to be short of what you have had in the past with max volume available..
Going back to where the evaluation of the RED LINE flow path was revealing no excessive DC level getting on that line from DC bleed thru from any of the power amps output circuity.
Now lets raise the volume and note that there is AUDIO also on that AF output line and it follows the RED LINE path also, and comes into the RED LINE sense input and immediately encounters a bodacious loading down with the two series 100 motherfarad capacitors.
They are being back/to/back polarity configured to be forming a non polarized capacitor for the incoming audio / same - same/ as AC .
That serious loading down of the signal along with its charge time constant involved results in a planned low level AC, then not being able to activate the D8-9-10-11 Full Wave Bridge Rectifier .
HOWEVER when it once does get enough level build up, to accumulate for creating a turn on of the Q2 transistor . . Whoop . . .Whoop . .There it is !
Then Q2 goes through its protection activation scheme again.
Q3 asked for me to introduce him . . .being neglected as he is . . . he just sits there and waits for that thermal switch across his base-emitter junction to engage and then he can then be as equally important as Q2 has been in the protection circuitry scheme...
This now fully lets me relate to my suspicions of a probable cause.
Referring to the power amp schematic, look to the LIGHT GREEN boxed area and see the C33 100 ufd electrolytic capacitor.
At that capaciitive value, it will require a given audio amplitude and time constant to affect the base of Q31.
Just let electrolytic capacitors do as they can do, and that is to have capacitance decline with time onset.
Then that 50 ufd unit will be responding MUCH faster and at a lower audio input level to reach that Q31 base turn on threshold .
On the other extrene let it drop to 0.1 ufd . . .which I have seen them do . . . and you would need a scoping to measure any delay, for that almost immediate protection circuit activation..
This would be the situation if you had one amp acting up, and had isolated it from the sense lines.
In YOUR case, the power output level does seem to be involved BUT equally so for all of the amps . . so you DON'T HAVE a singular unit with this problem.
Your power level threshold seems to be up to a moderate power level, before the protection threshold activation.
We can still relate to a power level related situation but lets go back to the RED ARROW input to the control board and the immediate loading down of the input audio by the C6-8 series non polarized pair.
If there is a capacitance decline in that combination, the charge time constant delay and charge level threshold will shoot up.
That will have Q2 activating at a smaller activation threshold than the initial design parameters.
If this does not prove to the case, as it will apply for all of the amps feeding into it, as you are currently experiencing.
You now move up to all 5 of the FUCHSIA marked boxes in the control circuitry, as they are also being associated to charge thresholds and charge time constants .
Just shunt each of the 4 capacitors with another 100 ufd and see if the protection cutout quirk, lets you then get MORE power before protection cut out, or if there is no cut out at all, with a component installed that fixes it .
The C6-8 pair will require two caps to test its position . . . . note the cap polarities .
SHORTHAND:
Check out 5 FUCHSIA marked up electrolytic capacitors.
Thasssssit . . . .
Le Schematiques . . . . . . .
73's de Edd
.
Sir Rick79 . . . . . . .
With your progress so far . . . looks like an amp with a high DC presence or imbalance on its output line is not being there . . . . what with all of your monitored DC outputs being way down in the sub 200 MV ranges.
What I suspicion is that the problem is in the section which I have prepped up referencing for you below.
Let me know if your unit is NOT using that 8 pin LM393 dual amp DIP, as another schematic shows there not being one . . . on one schematics revision.
This board is the collection point of sense and fault samplings from all of the power amp boards.
This board has the timed circuitry that gives a gradual power on to the power supply section via a
relay switched AC line thermistor.
Mutes the amps until ready to operate.
Drives your BLUE display LED's as well as the RED -GREEN power status LED's.
And finally, your area of interest, which is the Power amps sense and fault detection circuitry.
When you were checking back at the amps points of that <200MV DC presence, those are points that feed almost directly into a speaker.
Bad news if one of those output transistors shorts and puts either a full 56 plus or 56 minus volts to your speaker, or if there is a gradual change and that voltages starts gradually shifting up to that great of a value.
The sense circuitry would catch that transition quite rapidly and disconnect.
In actuality three factors are checked :
1 . . . . . No excess DC voltage level is on the line which feeds your speaker.
2 . . . . . No excess current is pulled by the power output transistors
3 . . . . . No excess audio power level gets to your speaker.
There is being an inset of one power amp section included in the bottom right corner of the info.
Herewith . . . a synopsis of your Harmonious Cardigan . . . . Autograph 2.2 . . . .resplendently compleat . . . .with its modus operandi explained for the section where I suspicion your trouble to be.
Referring to the power amp inset you will see the RED ARROW path that is sampling the juncture of the emitter resistors of the power output transistors.
When all is well in one or all of these amps, that juncture stays right at a VERY VERY low DC voltage , all of the audios wild voltage swings are occurring up at the collectors of the output transistors, in their replicating of the incoming audio wave forms.
If it is a DC voltage of high enough level to be a problem, it will be carried to the AMP reference RED ARROW input and get diode steered to the base of Q2.
If that level amplitude triggers Q2 into conduction its collector and its load resistor engages section 2 of the U2 556 dual section integrated circuit .
The output of section 2 of the 556 feeds pin 2 of U1A comparator, referencing against a voltage threshold set at its pin 3. Exceeding that reference lets the pin 1 of that comparator flip to a positive voltage which routes down to Q4 transistor .
With Q4's base drive level being met, it fully conducts and thereby robs the base drive from Q8 transistor which has been the relay driver for K1 relay which has been holding and responsible for the system power presence up to this point in time .
With it now disabled your protection engagement is accomplished.
With your low voltages . . . . we best look elsewhere.
Lets take the GREEN ARROW path this time.
Over at the power amps emitter circuitry you will see the tie in of all of the components in the SHADED GREEN area.
Here the circuitry is sampling between the top R57 emitter resistor and the R58 bottom emitter resistor.
The monitored voltage will be a reflection of the current passing through the pair.
As power increases the developed voltage sampled at R74 passes over to the C33 100 ufd capacitor and then that built up voltage ends up at the base of Q31, there is not an immediate response since the C33 time constant of charging up dampens any FAST response to change, with that response time constant being "fine tuned" a bit shorter by that 47 K shunting it.
Once that Q31 base turn on has it conducting, a fault condition is met and carried to the control board via the GREEN ARROW path.
D10 steering diode is isolating 4 other amps, simultaneously connected into this shared FAULT line.
Back at the control board, Q2 gets involved in producing the same protection activation scheme.
Lastly, what might be the most likely of the faults, and that would be the audio output level.
Considering that you are working up to the point where you encounter a protection circuit engagement.
That level just happens to be short of what you have had in the past with max volume available..
Going back to where the evaluation of the RED LINE flow path was revealing no excessive DC level getting on that line from DC bleed thru from any of the power amps output circuity.
Now lets raise the volume and note that there is AUDIO also on that AF output line and it follows the RED LINE path also, and comes into the RED LINE sense input and immediately encounters a bodacious loading down with the two series 100 motherfarad capacitors.
They are being back/to/back polarity configured to be forming a non polarized capacitor for the incoming audio / same - same/ as AC .
That serious loading down of the signal along with its charge time constant involved results in a planned low level AC, then not being able to activate the D8-9-10-11 Full Wave Bridge Rectifier .
HOWEVER when it once does get enough level build up, to accumulate for creating a turn on of the Q2 transistor . . Whoop . . .Whoop . .There it is !
Then Q2 goes through its protection activation scheme again.
Q3 asked for me to introduce him . . .being neglected as he is . . . he just sits there and waits for that thermal switch across his base-emitter junction to engage and then he can then be as equally important as Q2 has been in the protection circuitry scheme...
This now fully lets me relate to my suspicions of a probable cause.
Referring to the power amp schematic, look to the LIGHT GREEN boxed area and see the C33 100 ufd electrolytic capacitor.
At that capaciitive value, it will require a given audio amplitude and time constant to affect the base of Q31.
Just let electrolytic capacitors do as they can do, and that is to have capacitance decline with time onset.
Then that 50 ufd unit will be responding MUCH faster and at a lower audio input level to reach that Q31 base turn on threshold .
On the other extrene let it drop to 0.1 ufd . . .which I have seen them do . . . and you would need a scoping to measure any delay, for that almost immediate protection circuit activation..
This would be the situation if you had one amp acting up, and had isolated it from the sense lines.
In YOUR case, the power output level does seem to be involved BUT equally so for all of the amps . . so you DON'T HAVE a singular unit with this problem.
Your power level threshold seems to be up to a moderate power level, before the protection threshold activation.
We can still relate to a power level related situation but lets go back to the RED ARROW input to the control board and the immediate loading down of the input audio by the C6-8 series non polarized pair.
If there is a capacitance decline in that combination, the charge time constant delay and charge level threshold will shoot up.
That will have Q2 activating at a smaller activation threshold than the initial design parameters.
If this does not prove to the case, as it will apply for all of the amps feeding into it, as you are currently experiencing.
You now move up to all 5 of the FUCHSIA marked boxes in the control circuitry, as they are also being associated to charge thresholds and charge time constants .
Just shunt each of the 4 capacitors with another 100 ufd and see if the protection cutout quirk, lets you then get MORE power before protection cut out, or if there is no cut out at all, with a component installed that fixes it .
The C6-8 pair will require two caps to test its position . . . . note the cap polarities .
SHORTHAND:
Check out 5 FUCHSIA marked up electrolytic capacitors.
Thasssssit . . . .
Le Schematiques . . . . . . .
73's de Edd
.
Last edited:
Yes they all show 52V
.
Sir Rick79 . . . . . . .
With your progress so far . . . looks like an amp with a high DC presence or imbalance on its output line is not being there . . . . what with all of your monitored DC outputs being way down in the sub 200 MV ranges.
What I suspicion is that the problem is in the section which I have prepped up referencing for you below.
Let me know if your unit is NOT using that 8 pin LM393 dual amp DIP, as another schematic shows there not being one . . . on one schematics revision.
This board is the collection point of sense and fault samplings from all of the power amp boards.
This board has the timed circuitry that gives a gradual power on to the power supply section via a
relay switched AC line thermistor.
Mutes the amps until ready to operate.
Drives your BLUE display LED's as well as the RED -GREEN power status LED's.
And finally, your area of interest, which is the Power amps sense and fault detection circuitry.
When you were checking back at the amps points of that <200MV DC presence, that is a,point that feeds almost directly to a speaker.
Bad news if one of those output transistors shorts and puts either a full 56 plus or 56 minus volts to your speaker, or if there is a gradual change and that voltages starts gradually shifting up to that great of a value.
The sense circuitry would catch that transition quite rapidly and disconnect.
In actuality three factors are checked :
1 . . . . . No excess DC voltage level is on the line which feeds your speaker.
2 . . . . . No excess current is pulled by the power output transistors
3 . . . . . No excess audio power level gets to your speaker.
There is being an inset of one power amp section included in the bottom right corner of the info.
Herewith . . . a synopsis of your Harmonious Cardigan . . . . Autograph 2.2 . . . .resplendently compleat . . . .with its modus operandi explained for the section where I suspicion your trouble to be.
Referring to the power amp inset you will see the RED ARROW path that is sampling the juncture of the emitter resistors of the power output transistors.
When all is well in one or all of these amps, that juncture stays right at a VERY VERY low DC voltage , all of the audios wild voltage swings are occurring up at the collectors of the output transistors, in their replicating of the incoming audio wave forms.
If it is a DC voltage of high enough level to be a problem, it will be carried to the AMP reference RED ARROW input and get diode steered to the base of Q2.
If that level amplitude triggers Q2 into conduction its collector and its load resistor engages section 2 of the U2 556 dual section integrated circuit .
The output of section 2 of the 556 feeds pin 2 of U1A comparator, referencing against a voltage threshold set at its pin 3. Exceeding that reference lets the pin 1 of that comparator flip to a positive voltage which routes down to Q4 transistor .
With Q4's base drive level being met, it fully conducts and thereby robs the base drive from Q8 transistor which has been the relay driver for K1 relay which has been holding and responsible for the system power presence up to this point in time .
With it now disabled your protection engagement is accomplished.
With your low voltages . . . . we best look elsewhere.
Lets take the GREEN ARROW path this time.
Over at the power amps emitter circuitry you will see the tie in of all of the components in the SHADED GREEN area.
Here the circuitry is sampling between the top R57 emitter resistor and the R58 bottom emitter resistor.
The monitored voltage will be a reflection of the current passing through the pair.
As power increases the developed voltage sampled at R74 passes over to the C33 100 ufd capacitor and then that built up voltage ends up at the base of Q31, there is not an immediate response since the C33 time constant of charging up dampens any FAST response to change, with that response time constant being "fine tuned" a bit shorter by that 47 K shunting it.
Once that Q31 base turn on has it conducting, a fault condition is met and carried to the control board via the GREEN ARROW path.
D10 steering diode is isolating 4 other amps, simultaneously connected into this shared FAULT line.
Back at the control board, Q2 gets involved in producing the same protection activation scheme.
Lastly, what might be the most likely of the faults, and that would be the audio output level.
Considering that you are working up to the point where you encounter a protection circuit engagement.
That level just happens to be short of what you have had in the past with max volume available..
Going back to where the evaluation of the RED LINE flow path was revealing no excessive DC level getting on that line from DC bleed thru from any of the power amps output circuity.
Now lets raise the volume and note that there is AUDIO also on that AF output line and it follows the RED LINE path also, and comes into the RED LINE sense input and immediately encounters a bodacious loading down with the two series 100 motherfarad capacitors.
They are being back/to/back polarity configured to be forming a non polarized capacitor for the incoming audio / same - same/ as AC .
That serious loading down of the signal along with its charge time constant involved results in a planned low level AC, then not being able to activate the D8-9-10-11 Full Wave Bridge Rectifier .
HOWEVER when it once does get enough level build up, to accumulate for creating a turn on of the Q2 transistor . . Whoop . . .Whoop . .There it is !
Then Q2 goes through its protection activation scheme again.
Q3 asked for me to introduce him . . .being neglected as he is . . . he just sits there and waits for that thermal switch across his base-emitter junction to engage and then he can then be as equally important as Q2 has been in the protection circuitry scheme...
This now fully lets me relate to my suspicions of a probable cause.
Referring to the power amp schematic, look to the LIGHT GREEN boxed area and see the C33 100 ufd electrolytic capacitor.
At that capaciitive value, it will require a given audio amplitude and time constant to affect the base of Q31.
Just let electrolytic capacitors do as they can do, and that is to have capacitance decline with time onset.
Then that 50 ufd unit will be responding MUCH faster and at a lower audio input level to reach that Q31 base turn on threshold .
On the other extrene let it drop to 0.1 ufd . . .which I have seen them do . . . and you would need a scoping to measure any delay, for that almost immediate protection circuit activation..
This would be the situation if you had one amp acting up, and had isolated it from the sense lines.
In YOUR case, the power output level does seem to be involved BUT equally so for all of the amps . . so you DON'T HAVE a singular unit with this problem.
Your power level threshold seems to be up to a moderate power level, before the protection threshold activation.
We can still relate to a power level related situation but lets go back to the RED ARROW input to the control board and the immediate loading down of the input audio by the C6-8 series non polarized pair.
If there is a capacitance decline in that combination, the charge time constant delay and charge level threshold will shoot up.
That will have Q2 activating at a smaller activation threshold than the initial design parameters.
If this does not prove to the case, as it will apply for all of the amps feeding into it, as you are currently experiencing.
You now move up to all 5 of the FUCHSIA marked boxes in the control circuitry, as they are also being associated to charge thresholds and charge time constants .
Just shunt each of the 4 capacitors with another 100 ufd and see if the protection cutout quirk, lets you then get MORE power before protection cut out, or if there is no cut out at all, with a component installed that fixes it .
The C6-8 pair will require two caps to test its position . . . . note the cap polarities .
SHORTHAND:
Check out 5 FUCHSIA marked up electrolytic capacitors.
Thasssssit . . . .
Le Schematiques . . . . . . .
73's de Edd
.
Wow thanks for the reply, i really appreciate your detailed explanation, but me not having too much experience, i got kind of lost lol.
I dont understand what you mean by shunting the capacitors. Do you mean like solder another 100 ufd capacitor on each one? I would have to go buy some because i don't have any extras here at home, but would it be better to just replace them?
Rick ,
don't run buying anything yet.
There are things we can check before you do.
What are you driving the 2.1 amp with?
Try this:
physically disconnect all inputs to the amp.
Power the amp up and notice the LEDs behavior.
Do you get any flashing green? for how long?
when does the blue come on?
Any other noticeable colors?
don't run buying anything yet.
There are things we can check before you do.
What are you driving the 2.1 amp with?
Try this:
physically disconnect all inputs to the amp.
Power the amp up and notice the LEDs behavior.
Do you get any flashing green? for how long?
when does the blue come on?
Any other noticeable colors?
Im using a Harman Kardon HK3470 Receiver
I tried a Yamaha RX-V795a Receiver and even a cell phone, but the amp goes into protection regardless the type of audio source i use.
When i Power the amp, the light flashes green about 15 times before relays turn on and the word "Signature" stays illuminated in blue.
The HK3470 is a stereo receiver,you can only drive 2 channels at a time with it.
I assume you are using the "pre-out" for that.
If the volume level is below that causing the protect-trip,
Does the amp play clear sound?
What is the impedance of the speakers you are using?
I assume you are using the "pre-out" for that.
If the volume level is below that causing the protect-trip,
Does the amp play clear sound?
What is the impedance of the speakers you are using?
Yes, i tested the amp using the pre-outs on the hk3470 and i tested the amp with the pre-outs on the yamah RX-V795a receiver. I also tried other audio sources and they all have the same results. I used a large 12" woofer 8 Ohm Speakers and i also tried a small 8 ohm Speaker, but even with speakers disconnected from the amp, it still goes into protection mode when i turn the volume up.
Let's do a voltage test on the power switch/indicator board.
Use the DMM in DCV 2V range,
to measure the DC voltages on R2=10k,R3=100K,C9=104pF
Measure the voltages with volume at minimum,what do you read?
Slowly crank the voltage up till the protect trips.
What voltages do you measure just a moment before the trip point?
Use the DMM in DCV 2V range,
to measure the DC voltages on R2=10k,R3=100K,C9=104pF
Measure the voltages with volume at minimum,what do you read?
Slowly crank the voltage up till the protect trips.
What voltages do you measure just a moment before the trip point?
Ok i took readings at minimum volume and then i took readings as i raised the volume to where it goes into protection mode as you said...
R2 reads .001 at min volume, goes up to. .003 before going into protection mode. While in protection mode it reads .051
R3 reads .001 at minimum volume, and goes up to as high as 1.30 before going into protection mode. While in protection mode it reads .002
C9 reads .001 at minimum volume and stays that way before going into protection mode. While in protection mode it shows .000
o.K that is some progress.
While driving a single channel input only (note which one you drive).
Let's measure some main board voltages on
R7 , R73 , R121 , R169 , R217 all are 47K resistors,near the big blue caps.
Same as before, at minimum volume and than at a bit before the protect trip.
Be very careful not to short anything while probing.
The pic only shows 2 resistors the others same way.
While driving a single channel input only (note which one you drive).
Let's measure some main board voltages on
R7 , R73 , R121 , R169 , R217 all are 47K resistors,near the big blue caps.
Same as before, at minimum volume and than at a bit before the protect trip.
Be very careful not to short anything while probing.
The pic only shows 2 resistors the others same way.
Cool ok...
R7 reads .012 @ minimum volume and before protection mode it reads .036 and while in protection mode it reads .000
R73 reads .014 @ minimum volume and before protection mode it reads .044 and while in protection mode it reads .000
R21 reads .016 @ minimum volume and before protection mode it reads .043 and while in protection mode it reads .000.
R169 reads .014 @ minimum volume and before protection mode it reads .039 and while in protection mode it reads .000
R217 reads .015 @ minimum volume and before protection it reads .040 and while in protection mode it reads .000
o.k
The last set of test looks like the fault condition isn't due to over-current in the power Trs.
Another set of tests on the main board:
Same as before, at minimum volume and than at a bit before the protect trip.
DMM to DCV200 .
Black probe at one of the black speaker connectors(any would do fine).
Test the voltages on each side of R4 and R5 (a total of 4 points and 8 measurements).
The last set of test looks like the fault condition isn't due to over-current in the power Trs.
Another set of tests on the main board:
Same as before, at minimum volume and than at a bit before the protect trip.
DMM to DCV200 .
Black probe at one of the black speaker connectors(any would do fine).
Test the voltages on each side of R4 and R5 (a total of 4 points and 8 measurements).
R4 reads 52.4 at minimum volume on both sides and stays at 52.4 before protect trip.
R5 reads 00.0 at minimum volume on both sides and stays at 00.0 before protection trip
O.K
A few more tests on the switch /indicator board.
Same as before, at minimum volume and than at a bit before the protect trip.
DMM to DCV20 .
Black probe at one of the black speaker connectors(any would do fine).
Test the voltages on each side of R2 and R3 and R8 (a total of 6 points and 12 measurements).
A few more tests on the switch /indicator board.
Same as before, at minimum volume and than at a bit before the protect trip.
DMM to DCV20 .
Black probe at one of the black speaker connectors(any would do fine).
Test the voltages on each side of R2 and R3 and R8 (a total of 6 points and 12 measurements).
Ok...
R2 reads on both sides 0.01 at minimum volume and reads 0.01 on both sides before protect mode
R3 reads on both sides 0.01 at minimum volume and reads 0.04 on one side and 0.07 on the other side before protect mode.
R8 reads on both sides 11.12 at minimum volume and reads 11.20 on one side and 11.13 on the other side before protect mode
The last R3 measurements :
"R3 reads on both sides 0.01 at minimum volume and reads 0.04 on one side and 0.07 on the other side before protect mode."
do not agree with the R3 measurements on post # 32:
"R3 reads .001 at minimum volume, and goes up to as high as 1.30 before going into protection mode. While in protection mode it reads .002"
Please confirm the R3 measurements:
post #32
post #38
"R3 reads on both sides 0.01 at minimum volume and reads 0.04 on one side and 0.07 on the other side before protect mode."
do not agree with the R3 measurements on post # 32:
"R3 reads .001 at minimum volume, and goes up to as high as 1.30 before going into protection mode. While in protection mode it reads .002"
Please confirm the R3 measurements:
post #32
post #38
I rechecked R3 in DCV2 with the negative and positive probes and its .004 at minimum volume and goes up as high as .300 before protection mode. Sorry, not 1.30
I rechecked R3 in DCV20 with the Ground probe on the Speaker terminal ground and it reads 0.01 on both sides at minimum volume and reads 0.04 to 0.07 on both sides before protect mode
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