I have tried forcing the amp by grounding the tl494 but it will still shut down and nothing gets hot
ok jfets q217, q215, q115, q117 are pulling 29 volts at idle the rest are at 24 volts at idle at the gate. ok correct me on the right terminalogy q112, q113, q212 and q213 are the transistors the work with the fets pullin 29 volts and is there a problem with 4 volts difference wait i guess there would be thats what is shutting down the tl494 right? Any suggestions would be greatly apprieated
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All of the outputs are bipolar transistors, not jfets. The B688 and D718 transistors are the outputs. There are 6 outputs per channel.
Bipolar transistors don't have gates. Their terminals are the base, collector and emitter.
The term 'pulling volts' doesn't mean anything. I'm not sure what you mean.
Bipolar transistors don't have gates. Their terminals are the base, collector and emitter.
The term 'pulling volts' doesn't mean anything. I'm not sure what you mean.
I mean there is a 4 (29v) volt difference with the matched bipolar transistors compared to the other bipolars which are only at 24v at idle meaning when the amp is powered up with just remote voltage applied
You'll need to be much more specific.
With the black meter probe on one of the non-bridging speaker terminals, which transistors and which leg of those transistors are you referring to for the 29v and the 24v?
With the black meter probe on one of the non-bridging speaker terminals, which transistors and which leg of those transistors are you referring to for the 29v and the 24v?
q217 q215 q115 q117 (29 volts) with remote voltage applied bipolar
q116 q111 q120 q118 q218 q222 q121 q216 bipolar (24 volts)
I am wondering what the transistors connected to each bipolar is the small ones q112 q113 q212 q213 I am pretty sure they are pnps but what do they do?
q116 q111 q120 q118 q218 q222 q121 q216 bipolar (24 volts)
I am wondering what the transistors connected to each bipolar is the small ones q112 q113 q212 q213 I am pretty sure they are pnps but what do they do?
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You need to write in complete, precise language if you want others to understand what you're trying to convey. For example, what does 'with remote voltage applied bipolar' mean?
The smaller transistors function as drivers, predrivers and as part of the differential amplifiers. They consist of both NPN and PNP bipolar transistors.
Which terminals did you measure the voltage on?
The smaller transistors function as drivers, predrivers and as part of the differential amplifiers. They consist of both NPN and PNP bipolar transistors.
Which terminals did you measure the voltage on?
Sorry perry was using the battery post
doing it the right way middle leg of the fets there is a ten volt difference
q217, q215, q115 q117 26 volts
the rest are at 36 volts
Remote voltage is with amp powered up at idle with the + and - and the remote hooked up no speakers or nothing hooked to the rcas
black on non bridged speaker termial red on middle leg of the bipolar transistors
doing it the right way middle leg of the fets there is a ten volt difference
q217, q215, q115 q117 26 volts
the rest are at 36 volts
Remote voltage is with amp powered up at idle with the + and - and the remote hooked up no speakers or nothing hooked to the rcas
black on non bridged speaker termial red on middle leg of the bipolar transistors
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The outputs are bipolar transistors, not FETs.
The outputs should have both positive and negative voltage.
List all 12 FETs and the voltage (including polarity) on the center leg.
The outputs should have both positive and negative voltage.
List all 12 FETs and the voltage (including polarity) on the center leg.
(q216) d718 (+) 36v
q215 d718 (+) 46v
q121 d718 (+)36v
q222 b688 (-)36 v
q217 b688 (-) 24v
q218 b688 (-) 24v
Q116 d718 (+36)
q115 d718 (+38)
q111 d718 (+37)
B688 q120 (-37)
" q117 (-36)
" Q118(-36)
lol q215 is pulling excessive current
q215 d718 (+) 46v
q121 d718 (+)36v
q222 b688 (-)36 v
q217 b688 (-) 24v
q218 b688 (-) 24v
Q116 d718 (+36)
q115 d718 (+38)
q111 d718 (+37)
B688 q120 (-37)
" q117 (-36)
" Q118(-36)
lol q215 is pulling excessive current
For the channel with the 200 series parts (Q2..), there had to be an error. The three outputs of each part number (d718, b866) have their center legs directly connected by large traces. The voltage on those legs must be identical. If they are not, you have a burned trace or the voltage changed between the time you measured one then the next. Re-check them.
yeah I will recheck voltage is hard to get with amp going in and out of protection
ok everything is 36 volts that normal perry
ok everything is 36 volts that normal perry
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yeah
Well now I think whatever was making the amp go into protection has stopped being intermintent, I have +10 volts on the drain of all the z44's and +.50 volts on the gate, but the amp quit going into protection, the z44's are getting very hot so can't leave the amp on to long to try to figure out what is causing them all to get hot
Well now I think whatever was making the amp go into protection has stopped being intermintent, I have +10 volts on the drain of all the z44's and +.50 volts on the gate, but the amp quit going into protection, the z44's are getting very hot so can't leave the amp on to long to try to figure out what is causing them all to get hot
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OK pulled the bipolars out and got voltage readings
3 d718's right side of amp
base collector emitter
-22 +22 +.03 all three same
3b688 same side
-22 +22 +.03
left side d718
+22 +22 .00 all three
b688
+23 -23 .00 all three
amp is still in and out of protection with bjf out of amp
Looks like left side 718's are getting wrong polarity on the collector.
would it be a diode? Plus the voltage on the emitter on the right side?
3 d718's right side of amp
base collector emitter
-22 +22 +.03 all three same
3b688 same side
-22 +22 +.03
left side d718
+22 +22 .00 all three
b688
+23 -23 .00 all three
amp is still in and out of protection with bjf out of amp
Looks like left side 718's are getting wrong polarity on the collector.
would it be a diode? Plus the voltage on the emitter on the right side?
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The B688s on the right side appear to have the wrong polarity on their collectors but had the correct polarity the last time you posted the voltages. What changed?
all I did was take them out of the board, these voltages were with all of them removed
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Did you re-check the B688s with positive voltage on the center leg to see if it was indeed positive?
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