wrongdon
New member
I'm working on a s&t board for a friend.It has a nasty hum as soon as i power it up. So far i have replaced all of the electrolytic caps and the amp.The amp was originally a TDA2002 but i dropped in a TDA2003.I did not replace the tant caps at C16 and C22.When i turn either pot quickly the hum goes away for maybe a second.I am testing this on the bench with a switcher and jumpered for on board pots for volume adjustment.Touching the resistors and diodes between C42 and C24 makes alot more noise.I believe the board is functioning properly aside from this,at power on i get 6 flashes then i press the test button and it goes through all the words in its vocabulary followed by a beep and then it resets.
Any suggestions ?
Any suggestions ?