[CA] [CA11] Es75 Screen Interference from Alternator

[tidesinn]

I have an Es75 MFD and am receiving interference from the alternator which causes the screen to go black - for from a few seconds to 30 secs or more. Whenever I accelerate the engine from idle it causes the screen to go black. I have installed a voltage stabilizer on the power line which had no effect. I have experimented with a separate power line direct form batteries to MFD not near the alternator with no effect. I tried a shielded power line with no effect. I now suspect the interference is coming through the air and not through the power input line.
Is there something else I can try? I am surprised that others have not encountered this problem which makes me suspect my Es75 may be defective. Can I return it for Raymarine to check/replace it?

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum tidesinn,

Please click here to view a FAQ addressing this subject. It is unlikely that RF emissions would be responsible for the reported issue and on may easily identify whether this is the case by simply powering the MFD from another battery which is not connected to the vessel's power distribution system.

If a separate battery eliminates the issue, then it is likely there is a problem in the alternator output or the battery is in need of replacement.

This is indeed an unusual problem and may require further inspection of the power distribution system. It is also quite possible that the alternator may be generating insufficient power output to meet the demands of the engine system when operating at higher RPMs, resulting in insufficient power being supplied to the MFD. Should the MFD exhibit the reported symptoms when connected to the test battery, then it would be recommended that the MFD be sent to Raymarine’s Product Repair Center to be bench checked / serviced.