Hi, first time poster here
I picked up an old Technics SS-2900D from an opshop a few months ago. Long story short, it was a mess inside, dirt and bug parts. Cleaned it all out with isopropyl alcohol, contact cleaner in the volume potentiometers and fixed the crackle when turning up and down. I'm still having a few issues.
The rear left speaker output does not work, nor has it ever since I bought it (speaker works on other channels so not the speaker) There are 4 power amplifier boards inside, one for each channel. I put the board for the rear left channel into the slot for the front channel and no sound came out. I deduced the board was faulty. I tried putting a known good board from another channel in place of the rear left speaker, and it blew the output transistors and another resistor started smoking because of this.
I replaced the transistors and repaired both now broken boards (even the original one that never worked) however when I put any board in the slot for the rear left channel, it blows the output transistor. Clearly an issue with this channel further up.
Problem is I hardly know anything about circuitry or audio gear, and am very new and very inexperienced so I have no idea how to trace this channel back or what to look for.
No service manual available for this model that I can find anywhere on the Web.
Someone might be able to help me on here hopefully
I picked up an old Technics SS-2900D from an opshop a few months ago. Long story short, it was a mess inside, dirt and bug parts. Cleaned it all out with isopropyl alcohol, contact cleaner in the volume potentiometers and fixed the crackle when turning up and down. I'm still having a few issues.
The rear left speaker output does not work, nor has it ever since I bought it (speaker works on other channels so not the speaker) There are 4 power amplifier boards inside, one for each channel. I put the board for the rear left channel into the slot for the front channel and no sound came out. I deduced the board was faulty. I tried putting a known good board from another channel in place of the rear left speaker, and it blew the output transistors and another resistor started smoking because of this.
I replaced the transistors and repaired both now broken boards (even the original one that never worked) however when I put any board in the slot for the rear left channel, it blows the output transistor. Clearly an issue with this channel further up.
Problem is I hardly know anything about circuitry or audio gear, and am very new and very inexperienced so I have no idea how to trace this channel back or what to look for.
No service manual available for this model that I can find anywhere on the Web.
Someone might be able to help me on here hopefully
