need help

[geep6]

i have a power supply board out of a Compaq lcd and it has what i think is a ceramic smd capacitor with the markings of 7.5 B or 8 2u any ideal what they mean or what size it is it looks like it got really hot most of the electrolytic caps are bad vented it works intermediately here are a couple of pics of the board not very good quality though

[seanc]

Re: need help

I'm sorry, but your pictures are not good enough.
They're not focused at all.
I can make out a scorch mark, that's all.

Please attach them as per this thread:https://www.badcaps.net/forum/showthread.php?t=1868

[Dgtech]

Re: need help

It looks like you got some nice burn marks on that board. Too bad the pics are fuzzy. The only thing I can instruct you to do right now is to check solder joints near the burn marks and try to find out which component made it burn this bad. My gut tells me that a surface mount cap cant heat up this much. Please take better, clearer pictures of the boards and re-post using the "MANAGE ATTACHMENTS" on the posting page. No inline pictures.

[stj]

Re: need help

see if your camera has a macro function, if not then hold a magnifier infront of the camera lense - it works really well on cellfones!

[geep6]

Re: need help

here are a couple of pics of what i think is a smd ceramic cap this is what is on the under side of the board were the scorch mark is i tried to get in as close as i could magnifying glass ideal worked

[Ken256]

Re: need help

From the labels, it looks like the burned component was ZD984, which would be a zener diode. The component looks polarized, because it has a band on one side. The 7.5 could be the zener voltage, and the B could be the tolerance code. Look at the bad solder joint directly to the left of the burned component. If you don't have a service manual, it might be worth tracing out the surrounding circuitry to try and understand it and discover what the root failure was.