ifixit.com has nice step by step teardown instructions for your machine.
There are 2 ways to fix this issue:
1. Remove the logic board entirely from the machine and clean it.
2. Ask me nicely and I'll sell a working logic board for $50 + shipping.
Seriously, to thoroughly clean it and to ensure you got everything the logic board will need to be removed and cleaned. I also have 1 for sale if you want it. Either way that logic board has got to come out of the machine. I've field stripped so many Ti's over the years that I can pull the mobo in about 15 minutes, it's not as hard as you would think it would be.
There are 2 ways to fix this issue:
1. Remove the logic board entirely from the machine and clean it.
2. Ask me nicely and I'll sell a working logic board for $50 + shipping.
Seriously, to thoroughly clean it and to ensure you got everything the logic board will need to be removed and cleaned. I also have 1 for sale if you want it. Either way that logic board has got to come out of the machine. I've field stripped so many Ti's over the years that I can pull the mobo in about 15 minutes, it's not as hard as you would think it would be.