sony slv-810 and slv-825

[newzealand]

im not very good when it comes to servicing videos at all ,record players and cd players not to bad ,
i do not know how to clean a vcr head and may very well have damaged it ,
can any one point me in the right direction ,
what is happening is ,i have lots of horizontal screen noise on the 810 and the 825 just will not switch on at all .
im hoping that some one can walk me though a system to find out what may be up with these units as i have been using the 810 till the heads became dirty and i tried to clean them ,things got worse from there
thanks for taking a look at this .
mike

oh i can take detailed pics if you need to see any thing