I have a jensen mcd 5110 in a boat and it will not power up have looked at fuses and no luck

Place your question or part of it in YouTube. I'm sure there's a similar problem with a similar model.

I don't know much about marine radios. I am a ham radio operator, but they are much the same, if you do not hear any static (with squelch control turned down), then I suspect you are correct about the antenna. It could be the antenna itself, or the coax line to it, or the connection point at the radio or at the antenna. You're stuck without being able to remove it. If you do and find nothing at the radio, you'll need to check the connection at the antenna etc. Good luck.

then it might be wired wrong

Red- power Yellow-Memory Black-Ground

Unless the yellow wire has a fuse built into it then....
Yellow- Power Red-Acc/Ign Black- Ground

If the fuse you are asking about is on the radio t s usually a 10 or 15 amp fuse but if you mean for the power wire for a amp then it depends on the power amount of the amp....look on the amp and find the sum of the fuses on the amp and use a inline fuse that is the next fuse size sum...
Ex. 2 40 watt fuses on the amp then 40+40=80 watts so you would want to get a 100 watt fuse. Also remember you can never go to big for your inline fuse with a amp

Yes it does. I installed the same unit on my boat and ran an inline switch to the battery to turn it off so as to not wear the battery down.

Black is obviously ground. red is for switched power (only has power when vehicle is on) single yellow or orange is constant power Dual grey and dual white (solid grey/grey with black) and dual etc. are for speakers. the blue is for accessory power for amps and eq's. on the speaker wires the one with markings is for + and the soild is for -.

Do you still need the face plate for a 5110? I have one with case. if so e-mail me @ [email protected]

the unit is shot there is no hope for it. i have seen this problem many times in boats and never been able to fix the problem. i have had customers send the unit back to jensen and received a new one but check and see if your 1 yr guarantee is still good.

try ebay