Hello, I have a SONY EV-S9000E Hi8 deck which appears to work perfectly except that there is a thin distortion line that slowly drifts from top to bottom of the picture during playback.
It is NOT an issue with the tape, because the line drifts down over a different part of the picture each time the same picture is played. There seems to be no distortion of the (HiFi) audio which is stored on the same part of the tape as the picture.
Sometimes the line drifts down the blue "no-input" screen when the recorder is in STOP mode.
However, there are a few trailing black streaks on the LP picture where there is sharp contrast, which may imply head wear.
My first thought is to check the capacitors in the secondary part of the power supply.
There doesn't seem to be any visible leakage around the capacitors - although they are mounted hard against the PCB so their bases cannot be seen to look for leakage.
Looking at the Service Manual (https://elektrotanya.com/sony_ev-s9000e.pdf/download.html) the main PSU seems quite simple, but downstream there are a lot of voltage regulators on other boards.
Does anyone have past experience of servicing this (or similar) machine, who can guide me where to look next if replacing the PSU electrolytic capacitors does not help?