DCRU (upper) sound board problem

What transformer are you running that engine with?

no schematics.  If transformer works with other like DCRU/Horn sets ups the board is bad and needs to be replaced.  I may have one  G

The DCRU is a bottom board not the upper board.

Hi,

Thank you for quick replies. 
I think transformer (CW80) is not a source of problem since it works with my other MTH and Lionel trains.

I'm sorry for confusion with sound board name.
I thought that entire PCB unit is called DCRU so tried to distinguish PCB boards by their function. 

Chris that transformer will not work with some MTH engines and try another transformer because i had a PS2 3 volt it would not run it right and bell ring all the time.

I tested all transistors located on sound board (all were good) and after soldering them back sound board started to work correctly I still don't know what was the original issue. My best guesses are broken traces or cold solder joint. All in all problem solved. Thank you for your help.