Maker Pro
Maker Pro

Sony BVM-1416p - Fault


Oct 23, 2022
Oct 23, 2022
Hello, I wonder if anyone can help. I have a Sony BVM-1416p monitor. The fault is when powering on, the overload led flashes briefly and then the monitor shuts down. you can also hear a momentary "squawk" noise from the line drive panel EA.
Further checks found that the power supply is fine, (tested on another similar monitor). No immediate semiconductor fault appears to be on the Line output and DC to DC convertor stages on EA board (as no semiconductors are short circuit). Capacitors (electrolytic) appear ok.
If the Flyback transformer is disconnected, the symptoms are the same.
Disconnecting the scan coils however allows the power supply to stay on, but there is a low frequency buzzing noise which varies in pitch from Transformer T1 - this is associated with Q6 and the DC to DC converter section. Scope checks reveal that line (horizontal) drive is present under this condition. All voltages come up except the -150v (see below)
Plugging the scan coils back in causes the Power supply to shut down once more.
Voltages are all ok from the power supply except the -150V which is low at around -113v. I believe this supply is tied to the line section and when its working the -150V comes up. The power supply when tested in another monitor (BVM-1410p), was fine with all voltages including the -150v are correct.
Has anyone had a similar fault with this monitor? any help would be much appreciated.

Kind egards

Paul (UK)