well i think they would have matched if something didnt discharge... maybe the caps
cause now i cut out the Q108 and Q26 out of the circuit and measure all of the top row again and they ALL read no continuity and no resistance.. so i think what i was measuring earlier was something residual from the circuit..
anyways now they all measure no continuity
and if i measure the Q108 and Q26 out of the circuit on the FET itself all of the legs read 1 to 4 ohm they are busted... so do i need 2 IRF6215 or 4 (to match them)
what is driving me crazy is why does the LED doesnt light to say the amp is powered on because your telling me that even with those bad components it should power and maybe play sound...
cause now i cut out the Q108 and Q26 out of the circuit and measure all of the top row again and they ALL read no continuity and no resistance.. so i think what i was measuring earlier was something residual from the circuit..
anyways now they all measure no continuity
and if i measure the Q108 and Q26 out of the circuit on the FET itself all of the legs read 1 to 4 ohm they are busted... so do i need 2 IRF6215 or 4 (to match them)
what is driving me crazy is why does the LED doesnt light to say the amp is powered on because your telling me that even with those bad components it should power and maybe play sound...
on the lower heatsink
the 4 U1620 seems to be okay pin 1-3 show continuity and they dont show when doing 1-2 2-3 (CR1,2,3,4)
the 6 5n05hd on the left transfo shows (Q2,4,18,22,23,24)
1-2 OL
1-3 OL
2-3 200ohm and rising
the 6 5n05hd on the right transfo shows (Q5,6,7,9,10,11)
1-2 are shorted
2-3 500-600 and rising
1-3 500-800ohm and rising (maybe the same as above but its hard to tell cause sometime it starts at 500 some other at 600 ahd other times at 800 its probably my DMM not refreshing quick enough)
if i disconnect the 6 5n05hd on the right from the board and measure the FETs pin 1-2 are still shorted (failed..)
and if i measure on the board without the FETs conected i read the same as the left side
1-2 OL
1-3 OL
2-3 200ohm and rising
a question on the side
if i would have to replace only one failed 5n05hd could i replace it with a 3205 or would i need to match all of the 6 FETs concerned with all 3205 because of only one failed ? (the same principle as the 3415 ??)
the 4 U1620 seems to be okay pin 1-3 show continuity and they dont show when doing 1-2 2-3 (CR1,2,3,4)
the 6 5n05hd on the left transfo shows (Q2,4,18,22,23,24)
1-2 OL
1-3 OL
2-3 200ohm and rising
the 6 5n05hd on the right transfo shows (Q5,6,7,9,10,11)
1-2 are shorted
2-3 500-600 and rising
1-3 500-800ohm and rising (maybe the same as above but its hard to tell cause sometime it starts at 500 some other at 600 ahd other times at 800 its probably my DMM not refreshing quick enough)
if i disconnect the 6 5n05hd on the right from the board and measure the FETs pin 1-2 are still shorted (failed..)
and if i measure on the board without the FETs conected i read the same as the left side
1-2 OL
1-3 OL
2-3 200ohm and rising
a question on the side
if i would have to replace only one failed 5n05hd could i replace it with a 3205 or would i need to match all of the 6 FETs concerned with all 3205 because of only one failed ? (the same principle as the 3415 ??)
I think i know why the led is not working...
its cause my right transfo is not working... cause the FET are not feeding it (correct me if im wrong)
I was looking at the diagram and the transfo wich is feed by Q5,6,7,9,10,11 (the right one on the PCB and on the bottom right of the first page of the RF diagram) also feeds some secondary circuit that feeds the power LED (LEDSQR D22) so if my transfo is not getting juice from the 6 busted 5n05hd this circuit probably doesnt even have power
the left transfo still feeds a part of the juice since its working but its probably not enough to make it work... i dont know maybe i am wrong
its cause my right transfo is not working... cause the FET are not feeding it (correct me if im wrong)
I was looking at the diagram and the transfo wich is feed by Q5,6,7,9,10,11 (the right one on the PCB and on the bottom right of the first page of the RF diagram) also feeds some secondary circuit that feeds the power LED (LEDSQR D22) so if my transfo is not getting juice from the 6 busted 5n05hd this circuit probably doesnt even have power
the left transfo still feeds a part of the juice since its working but its probably not enough to make it work... i dont know maybe i am wrong
Parallel components must be replaced in groups if you want the amp to be as reliable as possible.
The LED is powered by the working transformer. Measure the DC voltage across the point where the wires solder to the board. What is the DC voltage?
The LED is powered by the working transformer. Measure the DC voltage across the point where the wires solder to the board. What is the DC voltage?
wich points ?
if you mean the led points i already did and there was not a ground and 2-3 volts i think the ground had 12 volts.. something like that ... in other words its not the lead that is broken...
if you want i can power up the amp to give you the exact information but i did not want to do it since i cut out a lot of the parts and i didnt knew if it was ok to do it ... dont want to blow something else cause there is some unconnected components...
do you think i can power it safely (with a 4Afuse) to do some diagnostic ?
so far i have unconnected the 2 busted 6215 on the top.. the top right 3415 wich i killed.. the 6 lower 5n05hd for the right transformer and 1 5n05hd for the left transformer wich was busted (i didnt tell you about cause its obvious it is since some legs are short so i considered it busted without talking about it) that is why i asked if i could replace only 1 5n05hd with a 3205 ... without replacing the 6 of them!!
lmk thanks
if you mean the led points i already did and there was not a ground and 2-3 volts i think the ground had 12 volts.. something like that ... in other words its not the lead that is broken...
if you want i can power up the amp to give you the exact information but i did not want to do it since i cut out a lot of the parts and i didnt knew if it was ok to do it ... dont want to blow something else cause there is some unconnected components...
do you think i can power it safely (with a 4Afuse) to do some diagnostic ?
so far i have unconnected the 2 busted 6215 on the top.. the top right 3415 wich i killed.. the 6 lower 5n05hd for the right transformer and 1 5n05hd for the left transformer wich was busted (i didnt tell you about cause its obvious it is since some legs are short so i considered it busted without talking about it) that is why i asked if i could replace only 1 5n05hd with a 3205 ... without replacing the 6 of them!!
lmk thanks
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If you have 3v across the LED and it's not lit, it's likely defective.
It probably won't power up through a 4 amp fuse but you can try it. I'd suggest a 10-15 amp fuse and have all remaining transistors clamped to the heatsink.
If you damaged one of the transistors for the left power supply, all 6 of those will have to be replaced also,
It probably won't power up through a 4 amp fuse but you can try it. I'd suggest a 10-15 amp fuse and have all remaining transistors clamped to the heatsink.
If you damaged one of the transistors for the left power supply, all 6 of those will have to be replaced also,
yeah i figured that out (for the left power supply...) it was dumb.. i wanted to try something and i forgot to solder leg 1 of the first FET on the left so when i powered it ... PEW ... thats why i ask if i can power it safely now.. to be safe 🙂
ill check on the led im going to the shop right now
ill check on the led im going to the shop right now
I got ground on both sides of the led...
you were right 4A didnt do it... i went to 10A and it was ok
you were right 4A didnt do it... i went to 10A and it was ok
i traced back on components to see if it had voltage earlier... inbetween D10 and D12 on the cathode side wich is feeding the +LV and inbetween D11 and D9 on the anode side wich is feeding the -LV i got ground of both of them also...
and if i trace it back to the trasnfo that is feeding them its the right one on the board... i have ground on both wires of the transfo also wich is 5-8 on the diagram...
and this is on the RIGHT transfo... would it not be powered if all of my power supply FETs on that one would be busted? if no juice going to the transfo... no juice going out right ??
basically the grounds im getting are the grounds going through the wiring of the transfo wich the other side is connected to the ground right??... since its not getting an electronic magnetic field from the rest of the transfo (powered by the power supply FETs) it doesnt create a voltage to feed the circuit?
maybe i am wrong here i am just trying to understand... that is my 2cents
and if i trace it back to the trasnfo that is feeding them its the right one on the board... i have ground on both wires of the transfo also wich is 5-8 on the diagram...
and this is on the RIGHT transfo... would it not be powered if all of my power supply FETs on that one would be busted? if no juice going to the transfo... no juice going out right ??
basically the grounds im getting are the grounds going through the wiring of the transfo wich the other side is connected to the ground right??... since its not getting an electronic magnetic field from the rest of the transfo (powered by the power supply FETs) it doesnt create a voltage to feed the circuit?
maybe i am wrong here i am just trying to understand... that is my 2cents
I was mistaken. I thought the auxiliary windings were on the other transformer. If they're on the transformer with the open winding, that power supply will have to be repaired for the amp to produce audio (and for the LED to light up).
EXCELLENT news 🙂
that is what i tought and i wanted to be shure cause i dont mind spending 50$ on repair parts if it works but if it doesnt it will be real sad...
the open winding is fixed... now .. i soldered it back to the board...
so if i sum it all up...
I need 12 of those IRF3205ZPBF to replace all the 5n05hd on the bottom (6 who shorted when the winding touched the case) and also 6 cause i did a mistake and blew one on the left so i replace them all...
then i need 4 IRF3415PBF and 4 IRF6215PBF to replace the upper right FETs that i blew when touching the case on my table
just want to be shure that those replacement parts are the right ones.. with all the PBF ZPBF thingy there is so much difference i just want to be shure they are good to go
now i know it will probably fix it cause the busted transfo supplies the led and other important parts of the amp ... when you told me the other transfo should power the led and the rest.. i was not shure anymore cause there was still that problem 😀
but now its all related so ill order that when you will confirm me the replacement numbers are good
one important question remains...
since the failed winding is on the "important" transfo who drives some auxiliary stuff... will the missing half a turn change something enough to make it not work ? I know its relative to exactly WICH winding failed but i didnt check it out before repairing it so i dont know :\
if you think it shouldnt change much i wont dissolder the winding to check it out...
but if you say it could be problematic depending wich one it is... i will do it and check it out to be certain wich one it is
BTW thanks for your help.. its really helping me out... i love that amp so much its part of my life now 😀 i want to save it
that is what i tought and i wanted to be shure cause i dont mind spending 50$ on repair parts if it works but if it doesnt it will be real sad...
the open winding is fixed... now .. i soldered it back to the board...
so if i sum it all up...
I need 12 of those IRF3205ZPBF to replace all the 5n05hd on the bottom (6 who shorted when the winding touched the case) and also 6 cause i did a mistake and blew one on the left so i replace them all...
then i need 4 IRF3415PBF and 4 IRF6215PBF to replace the upper right FETs that i blew when touching the case on my table
just want to be shure that those replacement parts are the right ones.. with all the PBF ZPBF thingy there is so much difference i just want to be shure they are good to go
now i know it will probably fix it cause the busted transfo supplies the led and other important parts of the amp ... when you told me the other transfo should power the led and the rest.. i was not shure anymore cause there was still that problem 😀
but now its all related so ill order that when you will confirm me the replacement numbers are good
one important question remains...
since the failed winding is on the "important" transfo who drives some auxiliary stuff... will the missing half a turn change something enough to make it not work ? I know its relative to exactly WICH winding failed but i didnt check it out before repairing it so i dont know :\
if you think it shouldnt change much i wont dissolder the winding to check it out...
but if you say it could be problematic depending wich one it is... i will do it and check it out to be certain wich one it is
BTW thanks for your help.. its really helping me out... i love that amp so much its part of my life now 😀 i want to save it
Unless you're 100% sure that you've repaired the winding correctly, I'd suggest that you leave it unconnected.
You likely need multiple 10 ohm gate resistors as well as the gate driver transistors (MPSA06 and MPSA56).
There may also be problems in the drive circuit for the outputs. You need to check the gate resistors for the output transistors that failed.
You likely need multiple 10 ohm gate resistors as well as the gate driver transistors (MPSA06 and MPSA56).
There may also be problems in the drive circuit for the outputs. You need to check the gate resistors for the output transistors that failed.
ill check all the gate resistors and transistors for the blown transistors to be certain..
can i check the gate driver transistors and resistors on the board without dissoldering ? the same way i did with the others ?
do you have a part number for those resistors if i have to order them
can i check the gate driver transistors and resistors on the board without dissoldering ? the same way i did with the others ?
do you have a part number for those resistors if i have to order them
For the power supply, with the FETs out of the circuit, you can check the gate resistors by measuring the resistance across them. You can be fairly sure that the gate driver transistors are in good condition by measuring the gate voltage. The DC voltage on every gate pad should be about 5v.
The gate resistors are 10 ohms, 0805 size.
The gate resistors are 10 ohms, 0805 size.
all of the top row i cant measure a voltage...its reading nothing.. could it be cause of the secondary circuits not powered cause of the transfo secondary side with no power that would not feed the rests of the circuits and this section would not have power to feed the gate driver transistors?
all of the upper resistances reads 25ohm (even if on the diagram is says 22 and 15 they are all the same color code red yellow white)
on the lower row i have 5.5V everywhere on the gates (drivers are probably ok) and most of the resistances reads 10ohm ill order some to replace the others (100,250,45 ohm etc)
can i check the upper row gate drivers in another way except the dc voltage?
all of the upper resistances reads 25ohm (even if on the diagram is says 22 and 15 they are all the same color code red yellow white)
on the lower row i have 5.5V everywhere on the gates (drivers are probably ok) and most of the resistances reads 10ohm ill order some to replace the others (100,250,45 ohm etc)
can i check the upper row gate drivers in another way except the dc voltage?
all of the top row i cant measure a voltage...its reading nothing.. could it be cause of the secondary circuits not powered cause of the transfo secondary side with no power that would not feed the rests of the circuits and this section would not have power to feed the gate driver transistors?
**** With no power from the aux windings, you can't check the drive voltages.
all of the upper resistances reads 25ohm (even if on the diagram is says 22 and 15 they are all the same color code red yellow white)
**** Those are 24.9 ohms. Schematic diagrams are rarely 100% accurate.
on the lower row i have 5.5V everywhere on the gates (drivers are probably ok) and most of the resistances reads 10ohm ill order some to replace the others (100,250,45 ohm etc)
**** ALL have to be within tolerance. If one gate resistor is out of tolerance, it could lead to the catastrophic failure of all of the FETs in the power supply the instant the supply is powered up.
can i check the upper row gate drivers in another way except the dc voltage?
**** Not without power from the aux windings.
**** With no power from the aux windings, you can't check the drive voltages.
all of the upper resistances reads 25ohm (even if on the diagram is says 22 and 15 they are all the same color code red yellow white)
**** Those are 24.9 ohms. Schematic diagrams are rarely 100% accurate.
on the lower row i have 5.5V everywhere on the gates (drivers are probably ok) and most of the resistances reads 10ohm ill order some to replace the others (100,250,45 ohm etc)
**** ALL have to be within tolerance. If one gate resistor is out of tolerance, it could lead to the catastrophic failure of all of the FETs in the power supply the instant the supply is powered up.
can i check the upper row gate drivers in another way except the dc voltage?
**** Not without power from the aux windings.
allright ill order the parts if i need something for the drives later on
I also have a pioneer gmx-960 to repair if you want to help 😀
do you have a diagram for that one?
I also have a pioneer gmx-960 to repair if you want to help 😀
do you have a diagram for that one?
what is the material, thin, thick or metal film ?.. wattage 0.1 or 0.125watt ? and 0.1 1 or 5% tolerance ?
for the 10 and 24.9 ohm resistors... i have an idea but not 100% certain
just to be shure to order the right ones
for the 10 and 24.9 ohm resistors... i have an idea but not 100% certain
just to be shure to order the right ones
For the SMD resistors, order the correct size. Don't worry about the wattage. Thick/thin film isn't important.
For the output gate resistors, you'll have to order 1/4w 1% metal film.
For the output gate resistors, you'll have to order 1/4w 1% metal film.
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