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Technics SU-G50

Hello everyone,

I recently obtained a very nice Technics stereo system made in 1990. It came complete with the tuner unit, equalizer, amp, cassette system, cd system and turntable, plus all wires and both original speakers! I am happy to say that everything seems to work EXCEPT the amp unit. I am unable to get both speakers to work through it. I have a decent amount of technical knowledge so I have tested various different scenarios including swapping speakers, swapping wires, etc. I have determined that the RIGHT ports (both A and B, and yes it has two different sets of ports for two different sets of speakers) do not work properly. Both LEFT ports work fine but both RIGHT ports are equally problematic. I can only hear a tiny bit of audio through the right channel, while the left works fine. As I said, I have some tech knowledge so I have done the obvious (switching wires to make sure the speakers and wires themselves are not the issue, and they are not). For example, if I plug the right speaker into the left port, it works fine. The right port side (again both A and B) barely work, I can only hear a very low amount of audio through them. What should I do? Is it possible BOTH side A and side B right ports are bad, yet BOTH left sides work fine? What are the chances? And is there any way to fix it? Should also let you know that it appears the cooling fan on the back of the unit is burnt out, it never turns on even if the unit is turned on.



Re: Technics SU-G50

Make sure the two jumpers are inserted on the back for pre-out/main in. If they are there then there may be a problem with the protection relay (dirty) or there may be bad components in the left amplifier.
Some cooling fans only operate when the amplifier gets warm.

Re: Technics SU-G50

did you try reversing your input leads, or try different inputs including cables, I had a similar problem on a Kenwood amp