I had the same problem, change IC 14 and 15 (RAM).

Bye

--- In tr-707@yahoogroups.com , "yodavst" <yodad2r2@...> wrote:
>
> hi all
> i need your help for repair my tr 707 crashed
> when turn On ,the cartridge led turn to the red or yellow
> No display no sound no led
> I've visually inspected the circuit board for
> bad components, but everything seems to be good!
> just some bad welding
> after new welding the problem presist
> when turn OFF the led 1,5,9,13 and pattern group turn to red
>
> thanks
>
> sorry for my bad english
>