Jeff Egg
Active Member
Working on this for a friend and I just don't know where to check next. I have Two problems that I have not been able to reliably repair.
1) The motor, most of the time seizes up, shutters or spins slowly. It will do any of these at startup or changing speeds or pretty much touching anything on the control panel. It will also do this after about 5 minutes of playing a record, sometimes. But, as I write this, its been okay. Could it be the 0.1uf capacitor of the power supply board? The Eroid, I'm not sure of the voltage. It has 1000V- and 400v~ and 250v~
2) The left channel is out, except when I put my receiver in mono. Stereo, nothing. I have continuity from the cartridge to the board but no sound, even when I touch the wires where it connects to the chassis. This one is wired with the ground jumper and no ground wire to the phono stage. Ive tried removing the jumper and adding a ground wire with no change. The is no hum from either channel, right one works great.
Ive checked the capicators on the speed control board and nothing is out of spec. I've adjusted the AC and DC voltages to their correct settings. The pots are clean and the speed selector contacts are not the issue, as far as I can tell. Resistors are okay.
I have not started to pull transistors yet to check them. I guess I should go through and double check voltages also. As this is a MKI, the board is a little different than a MKII. Thanks for hearing me out. Any help is greatly appreciated. (FYI made it through a whole album without the motor acting up, I still don't trust it)
Jeff
1) The motor, most of the time seizes up, shutters or spins slowly. It will do any of these at startup or changing speeds or pretty much touching anything on the control panel. It will also do this after about 5 minutes of playing a record, sometimes. But, as I write this, its been okay. Could it be the 0.1uf capacitor of the power supply board? The Eroid, I'm not sure of the voltage. It has 1000V- and 400v~ and 250v~
2) The left channel is out, except when I put my receiver in mono. Stereo, nothing. I have continuity from the cartridge to the board but no sound, even when I touch the wires where it connects to the chassis. This one is wired with the ground jumper and no ground wire to the phono stage. Ive tried removing the jumper and adding a ground wire with no change. The is no hum from either channel, right one works great.
Ive checked the capicators on the speed control board and nothing is out of spec. I've adjusted the AC and DC voltages to their correct settings. The pots are clean and the speed selector contacts are not the issue, as far as I can tell. Resistors are okay.
I have not started to pull transistors yet to check them. I guess I should go through and double check voltages also. As this is a MKI, the board is a little different than a MKII. Thanks for hearing me out. Any help is greatly appreciated. (FYI made it through a whole album without the motor acting up, I still don't trust it)
Jeff
