If they are mosfets and assuming GDS pin sequence, what is/are the through hole component(s) between the drain of one and the source of the other? Is it part of a switching supply?
If so, then the question becomes what made them overheat?
If they are mosfets and assuming GDS pin sequence, what is/are the through hole component(s) between the drain of one and the source of the other? Is it part of a switching supply?
If so, then the question becomes what made them overheat?
True, but AtomSoft described them as huge burnt spots. I originally had made my comment about overheated conditional, then decided a little simplification can avoid a lot of words.
The real issue is to fix the display. If AtomSoft thinks there is too much heat being generated in these devices, then that is where I would focus on the "why." I do agree the devices, if mosfets, are probably a symptom, not the cause.
Thanks guys ill get back here after work with more info. The monitor doesnt turn on at all. No power light. But all fuses are fine and power is on the main power PCB but some lines on secondary control pcb says 12v but has no power. The rest of the board looks perfect so i assume a DARK burning orange spot is a good place to start.
I think a power spike from either a blackout or something could have caused this whole monitor to die. Ill take some more pictures so i can follow all traces better and ill let you guys know whats going on ok. Thanks again for the advice.
Ok The burn spots are darker than in picture but flash is so good. Also the through hold parts are jumpers (WJ7) and that 1117 part has no power at all. So i assume a power supply issue is the main cause. I think regardless if the monitor is off or on as long as its plugged in it should have power since the main cpu controlls the LED(power) and buttons. So with no power coming in there no power for lcd control side
Thanks guys ill get back here after work with more info. The monitor doesnt turn on at all. No power light. But all fuses are fine and power is on the main power PCB but some lines on secondary control pcb says 12v but has no power. The rest of the board looks perfect so i assume a DARK burning orange spot is a good place to start.
Sorry, but that's an assumption from someone who doesn't repair TV's professionally
Boards (particularly in cheap make sets) commonly get discoloured in that way, it only very rarely is anything to do with the fault.
There are usually two separate power supplies on these sets, the main one and the standby one (usually either 5V or 3.3V) - the standby one runs all the time and supplies the micro, which in turn switches the main PSU ON and OFF. A fairly common fault is leaky rectifiers in the standby PSU - but just check the output voltage from it.
Those green caps in the background look puffy in the picture. One of my Samsung 213T's went belly up and replacing six, similar looking caps is all it took. None of the caps had actually popped yet.
Those green caps in the background look puffy in the picture. One of my Samsung 213T's went belly up and replacing six, similar looking caps is all it took. None of the caps had actually popped yet.
Yes, those six capacitors are all faulty - an ESR meter would be needed to test them, but any capacitor bulging like that requires replacing anyway.
High-ESR electrolytics is by far the biggest cause of problems in modern electronics. You should replace them with 105 degree ones from a decent manufacturer.
Look for low esr caps as opposed to general purpose for smps. The Panasonic FR series (and others) would work. Check the specs to match up the dia., height, and lead spacing of the caps you are replacing.
Look for low esr caps as opposed to general purpose for smps. The Panasonic FR series (and others) would work. Check the specs to match up the dia., height, and lead spacing of the caps you are replacing.
Atomsoft - the logo on those DPAK style drivers is from "Alpha & Omega Semiconductor", and like many manufacturers, they annoyingly assume you will include the letters in their stupid logo with the part number. So it's actually an "AOD408" you are looking for.
Here's a spec sheet in case you wind up having to cross it -
I don't know where you're getting your information, the ones I've dealt with had internal shorts (which is why they overheated and blew the safety) and the "most common problem" I saw was blown fuses and blown drivers.
And you can add "Illinois Capacitor" to the list of shame, we had to recall and replace all of them.
the ones I've dealt with had internal shorts (which is why they overheated and blew the safety) and the "most common problem" I saw was blown fuses and blown drivers.