4DTV transformer hum

[coinmaster32]

Every hour or so my transformer in the 922 will make a loud hum for 5-10 seconds.

Cause?

 

[Asket]

How long has it been doing that? Mine developed a low-grade hum about a week ago. Like a Lionel train transformer.

 

[truckracer]

probably needs a transformer replacement

 

[tvropro]

Could be a couple things. The transformer could be under a strain from excessive draw from a capacitor breaking down. Or the coating inside could be breaking down and a vibration is occurring.

 

[coinmaster32]

I notice when anything plugged into my surge strip turns on, it makes it hum, like my TV or laser printer.

 

[tvropro]

I know what is happening now. Your line voltage is low or dirty. I had a UPS on my 4D until it died and when it was running on the UPS alone the voltage was at around 90 volts and the sinewave was dirty off the inverter. Check your line voltage and see where it is at. My normal voltage is around 123 volts. I also have a very high amount of EMI noise filtration on my line that feeds all my gear. I also use a dedicated 15 amp AC circuit feeding all my gear with its own breaker and use 12 ga wire from the panel. If your line voltage is 120 plus then get a high quality EMI filter or design your own like I did. I built a surge suppressor/line filter in 96 that has take repetitive lightning strikes on the poles behind my house. And also been slammed with over voltage and under voltage conditions over the years and all my gear has never had one bit of trouble.

 

[coinmaster32]

Would having too much plugged into a outlet strip cause it? I notice it acts up every time I print a page or I. Have my stereo running

 

[tvropro]

Try plugging the 4DTV into the wall direct.

 

[Asket]

My voltage right now 122.3. Ive seen it run up to 140 at night only to drop to around 115 in the morning hours. I use an APC H10 to regulate voltage for sat , HiFi , TV & related equipment.

 

[sergei]

For one thing you should NOT have a laser printer plugged into a power strip as they can draw too much, just plug it directly into the wall socket.

 

[coinmaster32]

I plugged it into the wall socket and it still makes it hum. Maybe I need to buy a line filter?

 

[tvropro]

What's your line voltage?

 

[coinmaster32]

About 119.9 volts, with everything on, including the laser, plugged into a diff outlet, its 116

 

[tvropro]

Should be enough voltage, sounds like a EMI issue.

 

[coinmaster32]

Wouldn't EMI show up on the audio signal?

 

[n1wbd]

Sounds like a bad cap in the power supply.

I plugged it into the wall socket and it still makes it hum. Maybe I need to buy a line filter?

 

[tvropro]

Could be a cap failing dragging down the voltage. Need to take the hood off and check voltages.