suchenderxxx
Member
- Joined
- Apr 28, 2013
- Messages
- 12
Cheers,
i have got an Marantz Pmd 740 Six channel Mixer and 4 Track Recorder. Works and sounds good. Only Problem is that the 4th Input is not recording onto tape. If i Record the summing for the right Channel, then it is fine. So Recording Head is not the problem. I checked the cables and it is not getting any audio to the Recording for the 4th Track. i narrowed it to the mixing pcb it is sending track 3 but not the signal for track 4. i followed the schematics and i got till the njm 2068 LD. It has no output for Track 4 the opamp for Track 3 works so i tried to check the input with the oscilloscope and here is where im struggeling, the opamp on track 3 has an output and works like it should opamp on Track 4 has no output, now i tried to check the inputs of this opamps but i could get no signal on the pins 3 or 5 and this is for both opamps??? how can the opamp on track 3 have an output signal but nothing is going in? are im overlooking something?
i hope someone could take a look on the schematic ans show me how to check the opamp on track 4.
i have got an Marantz Pmd 740 Six channel Mixer and 4 Track Recorder. Works and sounds good. Only Problem is that the 4th Input is not recording onto tape. If i Record the summing for the right Channel, then it is fine. So Recording Head is not the problem. I checked the cables and it is not getting any audio to the Recording for the 4th Track. i narrowed it to the mixing pcb it is sending track 3 but not the signal for track 4. i followed the schematics and i got till the njm 2068 LD. It has no output for Track 4 the opamp for Track 3 works so i tried to check the input with the oscilloscope and here is where im struggeling, the opamp on track 3 has an output and works like it should opamp on Track 4 has no output, now i tried to check the inputs of this opamps but i could get no signal on the pins 3 or 5 and this is for both opamps??? how can the opamp on track 3 have an output signal but nothing is going in? are im overlooking something?
i hope someone could take a look on the schematic ans show me how to check the opamp on track 4.
