Onida 21" KYThunder Tuner problems

[deandany]

Before going into the problem, Following is the specification of myTV

ONIDA Purchased on july 2000

Model No : 21 KY Thunder
. Multi System
. 550 Watts PMPO
. 120 Program selectors
. Surround Sound
. KY Bass Blaster
. Diginet
. Digital Eye
. DVNR
. 3 Band Graphic Equaliser
. Games

The above is just to close in on the model and help u all to help me

The problem started1 week back... suddenly our cable relay went on and off as if some kid was playing with the cable by plugging it in and then taking it out...
So we first call our Cable service operators and after inspection of the cable they said cable if good... problem is with the TV... the connected our cable with neighbours TV and it worked ... so logicallly Cable is good... So we complained to the Onida Service center... they came and instantly (without even analysing the problem) said that we should change the tuner card... so we went into an AMC and changed it... it worked when he was here... but then after he went off, problems arised again... this time all we could see was cross lines on all the channels (the lines which come when we move from one channel to another ... ) and Auto scan (search) feature which searches for the channels stops after detecting first 4 channels... so we thought its time we gave Onida a tough time... but alas... bad luck...from today morning the Channels are working fine, Auto scan does its work perfectly... and when he came to our house he thought we were bluffing... what to do... he said he needs to take the TV for observation... as there maybe some problem with the microprocessor chip which scans the channel.!!!! then why did he change the tuner ??? Is this guy making sense.... Can anyone help us out...
thanks in advance