Is my circuit board dead?

I hadn't used my yeti 400 for 2 years and when I went to use it, it was completely dead and would not charge. I got a replacement battery and it worked that weekend for a trip until the battery drained and now it won't charge/hold a charge. When plugged in, nothing happens, it won't charge, the screen won't turn on, the blue charging light does not come on. I have disconnected the battery and let it sit - does not work