I have a solution idea for a major Tech company to use which leverages their current products and services. Have bounced it off others who agree that the idea sounds great. Have also built half of a prototype for the idea. I am unable, due to technical wall on my part, to build out the other half. Now at a point of asking "Now what?" Anyone have experience with this dilemma?
I'd say you need to bring someone in who can build the other half
Ideas a generally considered of very low value. I can buy limitless quantities of ideas for $10 each. What delivers value is being able to execute the idea in a useful way. So, it sounds like you're on the short side of this equation still. Getting others to agree with your idea's potential isn't hard, but figuring out how to deliver it typically is. If you are targeting a specific tech company with your idea, ring up their CEO and have a conversation in person. It works. Discuss the opportunity in terms of what the future looks like, not the path to getting there (your specific idea).
Most importantly, ask them lots of questions. The point of asking questions (even when you hopefully know the answers already) is to demonstrate how you think. If the CEO understands that you think the way they think, and also sees the opportunities you see, but hasn't figured out how to get from here to there, you can bet you'll be offered a job, or at least a project.
I have done this multiple times. You're not asking them to hire you. You're asking them if they see the same opportunity you see, and what they plan to do about it.