I horizontal scan lines on the top of the screen.

Hi and welcome to FixYa,

Offhand, you description would indicate an about to fail component in the vertical deflection circuitry; to be more specific the pump-up capacitor.  A most likely possibility is that the capacitor have started to dry up or leaking and therefore would require replacement.  This would be C407, a 100uF / 35V electrolytic capacitor.  Please note that this component has a polarity and the replacement must be soldered back in in a similar orientation.

Since the unit is open, might as well check conditions of C406, C408 and C409 (unlikely but worth the efforts).

Options then are:

• consider a DIY (do-it-yourself) repair if and only if very familiar with electronic components & circuitry, use of a DVM/VOM, a soldering iron/station and safe working practices with high voltages. Access to a Service Manual or at the very least, a schematic diagram would be a necessity;
  
• should you be uncomfortable with a DIY, perhaps your best bet would then be to seek the services of an authorized Toshiba Service Center (specially if still under some form of extended warranty) or a qualified professional.
  

Good luck and thank you for asking FixYa.