50PA4500 safety

[Jkirk3279@gmail.com]

I have the back off the TV, the red light is constantly clicking...

I was wondering if the clicking relay was on the Power board, and leaned closer.

I got a healthy shock when I tapped the central heatsink bar.

About sixty volts AC.

Just curious if this is normal, or if stray voltage means the board is hosed.

Thanks.

[stj]

Re: 50PA4500 safety

heatsinks are often live in some way, because they are in contact with metal components.

[R_J]

Re: 50PA4500 safety

Yes that is normal, the heatsink is likely connected to hot ground on the primary side of the power supply, and it can sit at about half the a/c line voltage.

[CapLeaker]

Re: 50PA4500 safety

that is why you are supposed to be really careful in the hot section of the PSU. Always take measurements first if you are not sure.

[SLK001]

Re: 50PA4500 safety

I got a healthy shock when I tapped the central heatsink bar.

...

Just curious if this is normal, or if stray voltage means the board is hosed.

Thanks.

Yes, it is normal that if you fix broken TVs, you will often receive a healthy shock. You will get used to it.

[Jkirk3279@gmail.com]

Re: 50PA4500 safety

Yes that is normal, the heatsink is likely connected to hot ground on the primary side of the power supply, and it can sit at about half the a/c line voltage.

Oh, of course.

My blood sugar must have been low, I knew that.

Thanks.

I was just worried that more than the cap was bad.

[budm]

Re: 50PA4500 safety

You should at least plug what ever you are working on into the GFCI outlet.

[Packard93]

Re: 50PA4500 safety

Always use safety when working in tv. It will have two sides on the power supply board hot and cold. HOT SIDE IS AC AND COLD IS DC. OR IT WILL SAY PRIMARY FOR AC AND SECONDARY FOR DC ON THE PCB LOOK FOR WHITE LINE .TV VOLTAGE CAN KILL SO DONT touch the hot and primary on any pcb. There live discharge is about 30 mins but not all capacitors can hold charge even after 30mins .