deveng
Well-known member
I'm repairing a Zed 22 FX for a friend and when I opened it up I found an unconnected brown wire going to the FX pcb. I traced the connection on the FX pcb and it goes to 2 series 47 ohm resistors then to pin 1 (input) of a ST L7805CV regulator. The problem is the other end. It looks like it was never actually soldered to the power supply board! The end is tinned but obviously never fully soldered. I have the power supply schematic but it doesn't indicate which point is for the FX board. The power supply schematic only has +/-15V, +48V and a +10v labeled pad (which actually measure 19.8V). The ST L7805CV spec sheet states for 5V regulator the input can be up to 35V. I assume the FX supply wire goes to the "+10v" pad with the series resistors used a dropping resistors.
I found an image on the internet of someone doing a direct out modification to a Zed 12 FX. One of the pictures does seem to confirm my assumption on connection. That picture shows the brown wire connected near or at the 10V labeled pad.
Can anyone confirm this?
I found an image on the internet of someone doing a direct out modification to a Zed 12 FX. One of the pictures does seem to confirm my assumption on connection. That picture shows the brown wire connected near or at the 10V labeled pad.
Can anyone confirm this?
