LG PSU Troubles

[jason22]

Hey guys, I recently repaired an LG EAY60968701 PSU (it was only a cold solder joint on the transformer) everything was running fine but whilst testing the voltages I accidentally shorted the +17v rail to Ground pin next to it with the multi-meter probe.

There was a small spark and now the TV will not turn on, the relay just clicks. I have checked the the voltage and it displays the correct 17v for a split second right before the relay clicks off. Checked the caps, the P-channel Mosfet seems to be fine (not shorted) but I can't for the life of me find out what was damaged in the short.

I just need a nudge in the right direction of what components may have been damaged from the short of the 17v rail.

Cheers, Jason

[budm]

Re: LG PSU Troubles

You can start by providing the good clear straight shot pictures of the whole top and bottom side of your board so we can see what we are dealing with.

[jason22]

Re: LG PSU Troubles

No worries mate, I should have been more forward thinking and posted some initially, my apologies. I was unable to locate a schematic, would have been handy.
Cheers, Jason

[budm]

Re: LG PSU Troubles

Can you not upload JPG instead of PDF?

[jason22]

Re: LG PSU Troubles

Certainly, they were over the max file size so I just quickly converted them with Foxit. Sorry for the inconvenience.

Here are the JPG's

[Duranitron]

Re: LG PSU Troubles

need to check all the component around the place you short the 17volts an open resistor perhaps or a toasted ic a schematic diagram would ease your hunt.

[Duranitron]

Re: LG PSU Troubles

Hey guys, I recently repaired an LG EAY60968701 PSU (it was only a cold solder joint on the transformer) everything was running fine but whilst testing the voltages I accidentally shorted the +17v rail to Ground pin next to it with the multi-meter probe.

There was a small spark and now the TV will not turn on, the relay just clicks. I have checked the the voltage and it displays the correct 17v for a split second right before the relay clicks off. Checked the caps, the P-channel Mosfet seems to be fine (not shorted) but I can't for the life of me find out what was damaged in the short.

I just need a nudge in the right direction of what components may have been damaged from the short of the 17v rail.

Cheers, Jason

i only have the EAY60968801 its almost the same schematics

[jason22]

Re: LG PSU Troubles

need to check all the component around the place you short the 17volts an open resistor perhaps or a toasted ic a schematic diagram would ease your hunt.

Hey mate, thank you for your diagram. I have checked extensively around the area and cannot find anything shorted or open that shouldn't be, i shorted the 17v rail right on the pin with the ground pin next to it if this helps.
cheers, Jason

[jason22]

Re: LG PSU Troubles

I have illustrated on the image where exactly I shorted the power rail, I have checked all resistors around the area and cannot find anything out of place. The board will still turn on for a second then click off, I'm not sure how to test that IC near it, I'm not sure if it could be damaged by something like that.
I'm really stumped on this one guys.
Cheers, Jason

[Duranitron]

Re: LG PSU Troubles

using the diagram can you illustrate to us where you short the 17v rail are you sure you short it on the ground or somewhere else. start there and replace all ic that is connected there happy hunting mate!