Mosconi amp fault

[Perry Babin]

How many header-type connectors do you have, in total on the 4 boards (RCA boards and the two behind them)?

 

[Wallace Wombat]

4, 1 x 12 pin per board

 

[Wallace Wombat]

 

[Wallace Wombat]

i do have a schematic for the amp if it helps, i cant get my head around it at this stage

 

[Wallace Wombat]

Per attached

 

[Perry Babin]

Does your service manual show the preamp board diagrams?

Are there any ICs on the rear two boards?

 

[Wallace Wombat]

 

[Wallace Wombat]

there doesn't appear to be

 

[Perry Babin]

Those are the ICs near the outputs. I was asking about ICs on the vertical boards.

 

[Wallace Wombat]

not sure in the diagram, but looking at the vertical boards i cant see any.

 

[Perry Babin]

They are designated as PCB2-5. Which two are the RCA boards?

 

[Wallace Wombat]

These?

 

[Perry Babin]

Yes. I need to know which 2 of those have the RCA jacks.

 

[Wallace Wombat]

PCB 4 and 5

 

[Perry Babin]

My fault.

You should have audio on pins 5 and 6 of PCB2. Confirm that you have audio and that one is weak.

 

[Wallace Wombat]

how do i check if they have audio

 

[Perry Babin]

How have you been checking for audio elsewhere?

 

[Wallace Wombat]

ah sorry
ill check

 

[Wallace Wombat]

no, millivolts only, checked pins 5 and 6. Same on pcb 3 too

 

[Perry Babin]

Do you have audio on the capacitors you checked earlier?