NES blue screen that just won't quit

[Gooch3008]

A non-toploading NES that I purchased for $2 at a local flea has died. Heres a run-down for you NES experts here.

• Ordered and replaced 72-pin
• Opened case and cleaned out not only what looked like 1/4 of a can of some ancient cola that was once spilled inside (just into the bottom of the case, not on the board)
• cleaned off the contacts on the mobo side with an eraser/91% alcohol
• disabled lockout chip (I was careful about this, did not damage anything)
• ALL of my games have been taken apart and cleaned thoroughly

This thing was working like a champ until recently. Suddenly it doesn't want to play games at all, only displaying a blue screen. I have fiddled with cart positioning and swapped out the RF cable and power cable for spares I have.

Is this something I can repair or is it dead? I feel like a dear friend has died even though I have only owned this NES for about a month.
I have already been eyeballing top-loaders on ebay and setting aside cash for a flea market console again....

[ahm]

Just a guess, but see if you have any leaking capacitors and replace them.
Also, check PC board traces for any corrosion.

Andy