[SOLVED] Part identification, resistor?

[Edumcg]

Can someone identify this component? Or perhaps explain what it is?

I am referring to the big metal rectangle with only an R marking.

If someone knows how to remove it, I would appreciate the explanation I figured I could heat it with a heat gun until it falls off but some guidance would be great.

Thanks in advance.

[mengfei]

looks like a Heatsink covering probably some Transistors or FET's
what's on the other side of the PCB directly beneath that metal

[xrunner]

It might be a shield covering components. Look at the sides and see if you can see anywhere it's tacked onto the PCB with solder.

[coromonadalix]

seems a shield to me

[Edumcg]

Attached picture of the other side.

I think it is a heatsink for the big diode. It has a B30R marking and looks similar to this one: https://pdf1.alldatasheet.com/datasheet-pdf/view/58877/DIODES/B330.html

With some courage I managed to lift it up and it was covering nothing so I guess is just to dissipate heat in case the board becomes too hot.

Thanks for your help

[Edumcg]

With a little bit of courage I managed to lift it up starting from the sides as you said so, thank you.

It was covering nothing but at least now I can see the paths and that helps on my quest to repair this thing.

[coromonadalix]

oh  an added heatsink + thermal pad onto a pcb surface  wow 


but  cooling an huge diode    must be reverse protection or forward polarity protection

Nothing fancy there


but you have some transistor, written FET301 on the pcb,  seems kinda brownish around it ?, must be the one who get hot,  the big resistor  must get hot too ??

Its a car radio?

And the aluminum plate must touch the enclosure ... ?

[Edumcg]

The FET301 seems ok, it doesn't look damaged.

The big resistor does look brownish but it is because I remove it to measure it. It is a four band resistor with a color code red, purple, gray and gold but I think is faulty because sometimes it gives me a reading of 1.1 ohm, others a reading of 0.7 ohm. If I am correct it should be 0.27 ohm consistently.

None of them get hot right now, when I turn it on the main power IC doesn't even get voltage on Vcc so I'm trying to figure out the path from 12V to the main power IC. Still no luck.

Yes! It is a car radio. Oh you're right! When it's assembled the aluminum plate does touch the enclosure