I can't recall for every model, but IIRC this one is the same as most other Toshibas. Having the service manual is always advised, however, and will tell you for certain.
Try:i have been unable to enter service mode . i have been trying with mute 3 times then mute hold menu
this has not worked on this model also tried volume all the way down then hold 9 still no go ?
any help would be great. thank you