LG 50 flashing screen-no picture/sound

[Cornboats]

I have an LG 50 that has no picture or sound as such. The sceen is black but has flashing white light. Sounds rather like a fluorecscent tube when the starter does't work, Noise is coming from the left side of the Ysus board.

I 've checked voltages around the boards and pinouts correspond with written values etched on boards .

I've swapped the y-sus and z sus boards with ones that I thought were ok & sympton remains the same.



What to check next?

 

[mulja]

check for burn chip on y-drive board top and bottom

[Cornboats]

Thanks for your response. I've given all boards a thorough visual check and can't see any burn marks or dark areas either on top or underneath.

The interesting thing is that I've got a spare pdp50X3 panel so I swapped everything over and guess what? exactly the same problem.

I was looking throught the Blue Ocean training manual -dowloaded from this forum. and it refers to maldischarge rom download.

I've never downloaded , what do think the chances of it being this is?