I believe I responded to you previously, but here's the link for parts and accessories, including the service menu.
FROM PREVIOUS POST "I have an HDMI input to my Samsung HL-S5687W from my Dish receiver and another from my computer going to the HL.
Today I ran a composite cable from the Dish receiver to the HL. In the process of doing so I had to remove both of the HDMI cables, after I plugged them back in I no longer had HDMI signals from the Dish receiver or computer."
I tried unplugging and plugging all devices per recommendations of responses to my earlier post to no avail.
I would like to get a service manual or at least a portion that would show how to replace whatever board controls the HDMI inputs.