/testforblock command doesn't reply with tesults

I swear I have done this perfectly, but for some reason it doesn't work. The coordinates are indeed correct, and it is a dropper so there's something in the NBT tag. It is a server, command blocks are enabled, and everything else works. (I have also tried testforblocks)

testforblock 14 8 -416 minecraft:dropper 0 {Items:[0:{Slot:1b,id:planks,Count:1b},{Slot:3b,id:planks,Count:1b},{Slot:4b,id:diamond_block,Count:2b},{Slot:5b,id:planks,Count:1b},{Slot:6b,id:stone_slab,Count:1b},{Slot:7b,id:stone_slab,Count:1b},{Slot:8b,id:stone_slab,Count:1b}]}

Should be the recipe

Though it's lenient when setting data, Minecraft requires you to give full item names when testing for them. Add "minecraft:" before each item name and it should work:

testforblock 47 4 -53 minecraft:dropper -1 {Items:[{Slot:1b,id:"minecraft:planks",Count:1b},{Slot:3b,id:"minecraft:planks",Count:1b},{Slot:4b,id:"minecraft:diamond_block",Count:2b},{Slot:5b,id:"minecraft:planks",Count:1b},{Slot:6b,id:"minecraft:stone_slab",Count:1b},{Slot:7b,id:"minecraft:stone_slab",Count:1b},{Slot:8b,id:"minecraft:stone_slab",Count:1b}]}