Schematic diagram need to identify the numbers on the output transistors

Contact Sundown direct and request the two parts.

https://www.google.com/search?q=sundown+sfb-1500d+schematic+diagram

https://www.google.com/search?q=transistor+1640s3

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If you wish to get some details; check the site linked here. Pull up older posts. Surf the site with patience. http://electronicshelponline.blogspot.com/
It will be the same number used for Green and Red color output transistors. Surf the above site. It has schematic diagrams to many popular brand TVs. You can point this out there.

Hi,
this power amp uses 2SA1962 and 2SC5242 output transistors. You can download the schematic diagram from this website.
Thanks.
gylacz

Good Luck.

I don't have a schematic but I have photos of that amp. What part do you need to identify?

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If the speaker is not blown, there must be an output capacitor. If no output capacitor, and you have a blown transistor the speaker will blow from DC current. You can further check the transistors with a multimeter. A transistor looks like 2 diodes and you should be abobe to test with a mulimenter like a diode test.

What are the part numbers on the transistors you replaced?

Did you replace transistors in the output section and the power supply section?

Does this amp have the defaced ICs labeled B52 and F16?

You have something in short circuit in power supply pattern, so filter coils are burnt. It may be voltage regulator, or regulating transistor, electrolytic capacitor or even shorted diode at pwr. input serving to protect in case of inverse polarity applied. Check all for short. Was it reverse polarity or overvoltage occured?

Mladen,
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If the service manual is not available on the JVC websites then you should just Google search "JVC A-GX3 service manual" There are many websites that archive manuals. You'll probably have to pay for a copy. Why can't you disassemble the unit and see the output transistor numbers first? More importantly how do you know this is the fault?

Problem is on Amp Assy. Resolder transistors and regulators that are mounted to the heat sink and replace both convergence output ICs. Replace the existing STK392-110 ICs with STK392-180 for improved reliability.