I'm currently replacing a PSU rectifier board in a Rotel Phono amp with a simpler version. The current Rotel Transfomer has 4 x outputs, 2 x blue wires which are the AC secondaries, a white wire which seems to go directly to earth and also a yellow wire which doesn't appear to go anywhere on the current board. The new board has only 3 inputs (2 x for the AC inputs and one for the earth). My question is, what happens to the yellow wire from the transformer which seems to be rdeundant?
I don't know what to make of the new board with markings versus the old board without markings.
The new board looks to have two footprints for a rectifier bridge rather than the one on the old one. So I assume the three pad sets on the edge are the connections to the transformer?
The new board looks to have two footprints for a rectifier bridge rather than the one on the old one. So I assume the three pad sets on the edge are the connections to the transformer?
- Show us the underside of the original board
- Unmount the transformer so you can actually see where they go? That'd really help.
There's 14,4 ohms through the blue secondaries and 7.5 ohms between the white wire and each of the blue secondaries. No continuity between the yellow and any of the other wires. The new board is a very simple circuit with 2 x AC input plus a ground and then a capped bridge rectifier before the option of 2 or 4 x bulk caps.
Then the yellow wire could be a shield.
Is the white wire connected to any other wires? It may be the center tap for the blue wire secondary.
Is the white wire connected to any other wires? It may be the center tap for the blue wire secondary.
All the wires are connected independently to the fits board:
Blue #1 - AC input (To Bridge Rectifier)
Blue ~2 - AC input (To Bridge Rectifier)
White - Connects to the Ground loop on the board
Yellow - Doesn't seem to go anywhere (Floating).
Blue #1 - AC input (To Bridge Rectifier)
Blue ~2 - AC input (To Bridge Rectifier)
White - Connects to the Ground loop on the board
Yellow - Doesn't seem to go anywhere (Floating).
The yellow wire was connected to the screw hole. It is pretty safe to assume it has to go to ground. Ground = metal = chassis = frame. Not the PSU "ground" or common. You might find a connection between the yellow wire and the transformer metal, but not necessarily.
Thanks. That's what I suspected. It looks like yellow is the shield then and needs to go to ac ground/chassis? White is the PSU ground/common?