I greet with all due respect . I have an amplifier Soundstream pca3500d the next problem. power transformers and it consists of two transistors IRF3205 20 , 10 for each transformer . a transformer with 10 fueling amplifier transistors . When you put it in other 10 transistors and powered amplifier circuit , the light turns red and the top five transistors heat up rapidly and are destroyed . I mention that all transistors are good , interative ka3525 is changed resistances transistors are changed . I currently disconnected first transformer transistors and when applied voltage across the transformer amplifier get some higher pitch about 10 seconds, the voltage across the capacitor is present . any advice is welcome . I apologize for beginner English . During today will add pictures to the issue in question
gate resistor is 100ko.i measured ka3525 and kia393
ka3525 value
1.-0.00
2-0.00
3-0.00
4-0.00
5-2.10
6-0,00
7-2.00
8-0.00
9-0.00
10-0.00
11-3,11
12-0,00
13-7,80
14-0.00
15-0.00
16-5.00
kia393 value
1-6.90
2-2.40
3-4.70
4-0.00
5-1.90
6-0,00
7-0,00
8-5.00
Power suply is ~160v .and work only one transformers with his transistors.
ka3525 value
1.-0.00
2-0.00
3-0.00
4-0.00
5-2.10
6-0,00
7-2.00
8-0.00
9-0.00
10-0.00
11-3,11
12-0,00
13-7,80
14-0.00
15-0.00
16-5.00
kia393 value
1-6.90
2-2.40
3-4.70
4-0.00
5-1.90
6-0,00
7-0,00
8-5.00
Power suply is ~160v .and work only one transformers with his transistors.
I greet you with respect. I changed some 47 ohm resistors and energized when first 5 transistors IRF3205 get hot . I can not leave because destroying tranzistorii.ceva fed opinions , ideas , be short between the transformer windings ??? I added some pictures of the amplifier .
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Photos are made without first transistors . (those heated ) .in this stage amplifier is powered and shortly after entering protection. when you put all transistors IRF3205 power supplied and the 5 transistors heat up , red LED light illuminates , the fan spins less. hd picture back today to see the situation. Thank you very much
If only 5 of the 20 transistors are heating up, it's very likely a problem with the driver transistors. Confirm that you read 0 ohms between the collectors of all of the PNP driver transistors and ground.
The fan speed decreases because the supply voltage is being dragged down by the excessive current draw.
The fan speed decreases because the supply voltage is being dragged down by the excessive current draw.
hello, between the midpoint of the capacitors and transistors collectors we did not find any value ( multimeter set to ko ) . Between minus point of the supply amplifier and collectors have found different values that I edited the picture . I give the impression that missing a transistor on the board , which I note with yellow arrow .
hello
i have a question..
How many volts should we have between outputA or B- GND (sg3525)..i now is PWM but approximate medium..thank you for all answers.!!
..i change all transistor 2SA and 2SC with MJE 340/Mje350..and between this operation i broke SG3525 becuse all transistor are hot ...i will cahnge sg3525 and i will back...
i have a question..
How many volts should we have between outputA or B- GND (sg3525)..i now is PWM but approximate medium..thank you for all answers.!!
is very hard for me because i don t have a osciloscope...but until i will buy a scope i try to repair without scope.with atx 12v source transformers from amplifier have noise and the power suply measured on the capacitor terminal have ~5vdc..i removed all mje340 mje 350 and tomorrow i will channge sg3525 with other ic new and i put again mje 340 350.....i m back on forum after this operation..thank you for answers :
:hello perry..today i measured the output from sg3525. OUT A/B-GND =~3.8 v with multimeter set AC.With multimeter set on the DC vlue is more up..~4v.(measured after output drivers bd139/bd140).when i put transistor IRF3205 in aprox 3 4 sec the transistor have 90 celsius degree and burn..i think gate resistor is to small..
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