Hi folks,
I found a working Technics SA-303 and want to replace the stock R703 (470ohms - 5 Watts) due to heat damage on the board (circled in red). I don’t think there are any faults. I’ve measured 40 volts across the resistor. That is 3.5 Watts for a 5 Watt rated resistor! I found a thick film 10 Watt TO-220 package resistor and a heatsink that will fit in the volume (30mm x 30mm x 30mm). Wondering if there is a more common replacement for these power resistors. All of the other 10 watt rated resistors are too big. Thanks. Schematic and photo attached.
I found a working Technics SA-303 and want to replace the stock R703 (470ohms - 5 Watts) due to heat damage on the board (circled in red). I don’t think there are any faults. I’ve measured 40 volts across the resistor. That is 3.5 Watts for a 5 Watt rated resistor! I found a thick film 10 Watt TO-220 package resistor and a heatsink that will fit in the volume (30mm x 30mm x 30mm). Wondering if there is a more common replacement for these power resistors. All of the other 10 watt rated resistors are too big. Thanks. Schematic and photo attached.
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I ended up using a larger 10 Watt rated cement resistor. https://www.mouser.com/ProductDetail/YAGEO/SQP10AJB-470R?qs=yNCrj0CQcyK75SvqZoj0hA==
securing a thick film resistor to some sort of heat sink was too much work. Also the service manual calls for a non-flammable resistor.
securing a thick film resistor to some sort of heat sink was too much work. Also the service manual calls for a non-flammable resistor.
Thanks for that information! I found the service manual on hifiengine (too large to upload here) and it doesn’t appear that the fusible type is required, only non-flammable. The list includes some resistors labeled as fusible-type. As a side note the wattage ratings are in error. What would you recommend if not the Yageo 10 watt resistor?
