Now i noticed that the smaller Q108 and Q208 isnt according
to schematic.
Q108 and Q208 same
leg 1 -1v
leg 2 3.8v
leg 3 -0.4v
Should be at
-3.9
3.6
3.6
Q111-114 (Q124-135 cant find in schematic. placed on a
small vertical board.) Gets REALLY hot after 10-15 min.
Is that normal? I have everything outside the chassi but
still with the aluminium heat sinks on of course.
Q211-214 (Q124-135 cant find in schematic. placed on a
small vertical board.) Same here, gets really hot!
Maybe its normal...
I also noticed that the voltage between Terminals Ground
and Battery just read about 5.9 volts when the amp wont
power up. But when i get it to power up it reads about 12 volts.
Is it something wrong here to? I get confused
Happy evening everybody I belive in you guys to help me!
to schematic.
Q108 and Q208 same
leg 1 -1v
leg 2 3.8v
leg 3 -0.4v
Should be at
-3.9
3.6
3.6
Q111-114 (Q124-135 cant find in schematic. placed on a
small vertical board.) Gets REALLY hot after 10-15 min.
Is that normal? I have everything outside the chassi but
still with the aluminium heat sinks on of course.
Q211-214 (Q124-135 cant find in schematic. placed on a
small vertical board.) Same here, gets really hot!
Maybe its normal...
I also noticed that the voltage between Terminals Ground
and Battery just read about 5.9 volts when the amp wont
power up. But when i get it to power up it reads about 12 volts.
Is it something wrong here to? I get confused
Happy evening everybody I belive in you guys to help me!
I measured from TP1 (located on the right corner of schematic page 15 in service manual) www.itxpress.se/mrv.pdf
Is that the center tap common point?
If i measure from RCA shield to TP1 the value starts from 1kohm
and climbing above 11kohm. Is something wrong here?
**** This is normal.
Could it just be some faulty capacitor wich is doing this?
**** What's probably happening is that the protection is malfunctioning when the B+ and remote are applied at the same time. When powered up normally, the protection works as it should and shuts the amp down due to a fault.
Now i noticed that the smaller Q108 and Q208 isnt according
to schematic.
Q108 and Q208 same
leg 1 -1v
leg 2 3.8v
leg 3 -0.4v
Should be at
-3.9
3.6
3.6
**** These are the small biasing transistors located at the end of the row of output transistors (correct me if that's not the case). These will typically only be correct when the amp is fully powered up and operating properly.
Q111-114 (Q124-135 cant find in schematic. placed on a
small vertical board.) Gets REALLY hot after 10-15 min.
Is that normal? I have everything outside the chassi but
still with the aluminium heat sinks on of course.
Q211-214 (Q124-135 cant find in schematic. placed on a
small vertical board.) Same here, gets really hot!
Maybe its normal...
**** This is not normal. The transistors on the vertical boards seem to be a modification aimed at increasing reliability. These outputs work in parallel with the other outputs. You should be able to confirm the parallel connection with your ohm meter.
I also noticed that the voltage between Terminals Ground
and Battery just read about 5.9 volts when the amp wont
power up. But when i get it to power up it reads about 12 volts.
Is it something wrong here to? I get confused
**** When the amp won't power up, it's probably trying to power up but something is causing excessive current draw and that's dragging the voltage of your supply down to 5.9v.
**** Something is causing the output transistors to heat up. This could be due to a defective driver transistor or a failed output transistor. If you've checked all of the outputs and none are defective, check the smaller transistors near the output section of the amp.
**** There are two connectors with blue, black and clear wires, unplug then to see if the amp will power up normally (applying remote voltage 'after' B+ and ground are connected. If so, reconnect one and see if the amp powers up normally. Then disconnect it and plug the other one in to see if it will power up normally.
Is that the center tap common point?
If i measure from RCA shield to TP1 the value starts from 1kohm
and climbing above 11kohm. Is something wrong here?
**** This is normal.
Could it just be some faulty capacitor wich is doing this?
**** What's probably happening is that the protection is malfunctioning when the B+ and remote are applied at the same time. When powered up normally, the protection works as it should and shuts the amp down due to a fault.
Now i noticed that the smaller Q108 and Q208 isnt according
to schematic.
Q108 and Q208 same
leg 1 -1v
leg 2 3.8v
leg 3 -0.4v
Should be at
-3.9
3.6
3.6
**** These are the small biasing transistors located at the end of the row of output transistors (correct me if that's not the case). These will typically only be correct when the amp is fully powered up and operating properly.
Q111-114 (Q124-135 cant find in schematic. placed on a
small vertical board.) Gets REALLY hot after 10-15 min.
Is that normal? I have everything outside the chassi but
still with the aluminium heat sinks on of course.
Q211-214 (Q124-135 cant find in schematic. placed on a
small vertical board.) Same here, gets really hot!
Maybe its normal...
**** This is not normal. The transistors on the vertical boards seem to be a modification aimed at increasing reliability. These outputs work in parallel with the other outputs. You should be able to confirm the parallel connection with your ohm meter.
I also noticed that the voltage between Terminals Ground
and Battery just read about 5.9 volts when the amp wont
power up. But when i get it to power up it reads about 12 volts.
Is it something wrong here to? I get confused
**** When the amp won't power up, it's probably trying to power up but something is causing excessive current draw and that's dragging the voltage of your supply down to 5.9v.
**** Something is causing the output transistors to heat up. This could be due to a defective driver transistor or a failed output transistor. If you've checked all of the outputs and none are defective, check the smaller transistors near the output section of the amp.
**** There are two connectors with blue, black and clear wires, unplug then to see if the amp will power up normally (applying remote voltage 'after' B+ and ground are connected. If so, reconnect one and see if the amp powers up normally. Then disconnect it and plug the other one in to see if it will power up normally.
Q111-Q114 and Q124-125 voltage OK!
Q211-Q214 and Q224-Q225 voltage OK!
Gets Really hot.
Q319-Q322 voltage OK! Q307-308 voltage OK!
Q108 and Q208 voltage -1 3.8 -0.4
they ar placed "between Q109 and Q110
Q209 and Q210. Not according to voltage
readings on schematic.
Q106-Q110 voltage OK!
Q206-Q210 voltage OK!
I have checked all of the output transistors.
And all the driver transistors, maybe ill check
the smaller ones around them?
I think i check ALL of the smaller transistors since
the big ones is OK!
I mean it will probably show up on some transistor
even if its a resistor capacitor or whatever thats
defect, am I right? It must show upp in to much
voltage on some of the smaller transistors
that drive the bigger ones. Or maybe it could
be something else that produces the big current
in the output transistors
If i disconnect the big connectors with blue, black and clear
wires the amp actually works fine, it powers up when i
connect the remote After ive connected to battery.
I cant connect either of the connectors then i have
the same prob.
This amp is getting to my head!
Have to measure all the smaller transistors after work then
i get back to you, keep faith in me =)
Q211-Q214 and Q224-Q225 voltage OK!
Gets Really hot.
Q319-Q322 voltage OK! Q307-308 voltage OK!
Q108 and Q208 voltage -1 3.8 -0.4
they ar placed "between Q109 and Q110
Q209 and Q210. Not according to voltage
readings on schematic.
Q106-Q110 voltage OK!
Q206-Q210 voltage OK!
I have checked all of the output transistors.
And all the driver transistors, maybe ill check
the smaller ones around them?
I think i check ALL of the smaller transistors since
the big ones is OK!
I mean it will probably show up on some transistor
even if its a resistor capacitor or whatever thats
defect, am I right? It must show upp in to much
voltage on some of the smaller transistors
that drive the bigger ones. Or maybe it could
be something else that produces the big current
in the output transistors
If i disconnect the big connectors with blue, black and clear
wires the amp actually works fine, it powers up when i
connect the remote After ive connected to battery.
I cant connect either of the connectors then i have
the same prob.
This amp is getting to my head!
Have to measure all the smaller transistors after work then
i get back to you, keep faith in me =)
Still doing some measuring, i found a bad electrolyt, a small
one in the begining of the power supply.
Measured only 12 kohm, think that they should show
infinit in a 1 sec time.
Is there some other good way to measure them?
Only have Multimeter and a oscilloskop.
Found that many of the smaller ones 0.047uF dont
read any ohms at all, dont get any indication att all on the multimeter. Should it be so? Disconnected one leg.
one in the begining of the power supply.
Measured only 12 kohm, think that they should show
infinit in a 1 sec time.
Is there some other good way to measure them?
Only have Multimeter and a oscilloskop.
Found that many of the smaller ones 0.047uF dont
read any ohms at all, dont get any indication att all on the multimeter. Should it be so? Disconnected one leg.
Did you find any broken connections between Qx08 and the driver transistors?
If not, how can you have the correct voltage on Qx09 and Qx10 but not have the correct voltage on Qx08?
There is nothing between the collector of Qx08 and the base of Qx09 except a 4.7 ohm resistor. There can't be much of voltage drop if the resistor is within tolerance.
If the connections to the bias transistor (Qx08) are broken, that could make the outputs overheat. You need to check all connections with an ohm meter.
If not, how can you have the correct voltage on Qx09 and Qx10 but not have the correct voltage on Qx08?
There is nothing between the collector of Qx08 and the base of Qx09 except a 4.7 ohm resistor. There can't be much of voltage drop if the resistor is within tolerance.
If the connections to the bias transistor (Qx08) are broken, that could make the outputs overheat. You need to check all connections with an ohm meter.
No i did not find any broken connections.
The strange thing is that both Q108 and Q208
is showing the exakt same value.
pin1 pin2 pin3
-1v 3.8 -0.4
Should be
-3.9 3.6 3.6
I have been checking some electrolyts now and i found one
thats was leeking. So now the outputs dont overheat.
Q110 gets ******* hot after only 1 minute or so.
Dont dare to keep the power on for so much longer then.
Very strange.. I tryed to switch with Q210 that is the exakt
same transistor but for the other channel. But still Q110
gets hot like hell. Something is very strange.
I checked all the voltages on the regulators and the outputs
and they are ok withing a few percent.
One more thing i noticed strange is that if i ohm measure
channel 1 and channel 2(outputs)
I get about 3.85Mohms
But sometimes i only get 0.9 Mohms on one of the channel.
Cant remember wich channel.
I taught it would be nice to fix the overheat problem before
fixing the ground prob, dont think they are really related.
Maybe i should replace ALL capacitors? Was hoping to not do so
since its quite a work and costs money to do.
I mean, i measured most of the transistors and they are OK
according to schematic. If some would be defective then
it would show up on the voltages right?
One of the protection transistors Q115 should have 0v on all 3 legs. But the middle one is alternating between 0 and a lower voltage reading, cant read it. The other 2 legs are showing
some milivolts but thats normal i think. Very strange.
Somewhere there is a fire but i cant se the smoke, why!? =)
Been investigating this over a week now without any solution.
The strange thing is that both Q108 and Q208
is showing the exakt same value.
pin1 pin2 pin3
-1v 3.8 -0.4
Should be
-3.9 3.6 3.6
I have been checking some electrolyts now and i found one
thats was leeking. So now the outputs dont overheat.
Q110 gets ******* hot after only 1 minute or so.
Dont dare to keep the power on for so much longer then.
Very strange.. I tryed to switch with Q210 that is the exakt
same transistor but for the other channel. But still Q110
gets hot like hell. Something is very strange.
I checked all the voltages on the regulators and the outputs
and they are ok withing a few percent.
One more thing i noticed strange is that if i ohm measure
channel 1 and channel 2(outputs)
I get about 3.85Mohms
But sometimes i only get 0.9 Mohms on one of the channel.
Cant remember wich channel.
I taught it would be nice to fix the overheat problem before
fixing the ground prob, dont think they are really related.
Maybe i should replace ALL capacitors? Was hoping to not do so
since its quite a work and costs money to do.
I mean, i measured most of the transistors and they are OK
according to schematic. If some would be defective then
it would show up on the voltages right?
One of the protection transistors Q115 should have 0v on all 3 legs. But the middle one is alternating between 0 and a lower voltage reading, cant read it. The other 2 legs are showing
some milivolts but thats normal i think. Very strange.
Somewhere there is a fire but i cant se the smoke, why!? =)
Been investigating this over a week now without any solution.
If Q110 is getting hotter than Q210, it seems like it's having to work too hard. When you checked the outputs, did you pull the legs off of the board?
If you increase the bias (via the bias pot), the voltage on the bias transistors may get to the specified voltage.
I don't think changing the capacitors will help.
If you increase the bias (via the bias pot), the voltage on the bias transistors may get to the specified voltage.
I don't think changing the capacitors will help.
No i have just checked the outputs by measuring the voltages.
Yes maybe but i adjusted the bias according to schematic.
about 5mV.
What can cause Q110 to be so ******* hot, cant touch it after 2 mins, but its just Q110 not any of the other transistors, they
are at normal temperature.
If you were me what would you do?
Yes maybe but i adjusted the bias according to schematic.
about 5mV.
What can cause Q110 to be so ******* hot, cant touch it after 2 mins, but its just Q110 not any of the other transistors, they
are at normal temperature.
If you were me what would you do?
By the way i checked for a new transistor.
we have a shop here thats called "japan electronic center"
and they only had one with the name IRF 540, but it seems
to be the same.
I want a IRF9540FS but maybe IRF 540 will do well?
Or do you have any suggestions
Thanks by the way for helping me out!
we have a shop here thats called "japan electronic center"
and they only had one with the name IRF 540, but it seems
to be the same.
I want a IRF9540FS but maybe IRF 540 will do well?
Or do you have any suggestions
Thanks by the way for helping me out!
I'm not sure what the FS suffix indicates on the Alpine part number. If the transistors are standard TO-220 devices (not fully encapsulated), virtually any IRF540/IRF9540 in the TO-220 package will work.
If there is a small insulator between the clamp and the tab of the transistor, you must replace it when you reassemble the amp. The clamps must NOT come in contact with the metal tab of the transistors.
If there is a small insulator between the clamp and the tab of the transistor, you must replace it when you reassemble the amp. The clamps must NOT come in contact with the metal tab of the transistors.
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