QSI proto 1

If the speaker is good, have you checked the volume pot?  Unplug the pot and jumper the two wires center to max volume on the board and see if that changes things.  Try wiggling the two boards to clean oxidation off the pins between the boards.  Those are two obvious things that crop up.

I have some pieces and did change the volume pod and the top board has been changed with another one also still same. I can live with it as the little eng that could does run well, Thanks for the suggestion. note also when I remove the boards and bench power it the noise will go away. Has the sound like neon lights interfere. I would think maybe a motor but it does it in neutral. Why only proto 1 do I seem to have these problems? I got it from my brother not working. All I did was hold the whistle button down and turned off power and it worked.  If you have any other ideas I can try I welcome them. Respectfully ROY

How close is the battery and cables to the boards in the engine?  But, if you raise voltage high and above 10V the static starts coming in, most likely a voltage regulator failure allowing DC voltage to get too high.  Is this the 3 board stack QSI system, or the 2 board stack MTH System.  They are different.  G

just a 2 stack  Roy I am just done with MTH I continue to have issues with them. I guess when you buy used junk that is what you get.  Thank you all   Respectfully Roy

Roy O posted:

I am just done with MTH I continue to have issues with them. I guess when you buy used junk that is what you get.  Thank you all   Respectfully Roy

I have been buying new MTH since 1997. Very few problems ever.

MELGAR

You have probably bought them new. They make great looking products. Have better luck with lionel.  With all trains everyone has a opinion. Its all good. Work with electronics as a automotive service tech. specialty was electronics. Trains is a new area for me and I get frustrated when I realize I do not have the training to repair.  Roy  Have a good day.