Advantech DAC-BC05 Power problem

[andrestecno]

This small motherboard does not turn on, I have measured the outputs of the sources and most of them seem to work except 2, one is from the Q5 and the other from the U6(Isl6537acrz), which apparently could be the problem since the 12v does not reach it. They go through R257. Looking at U6 it seems burnt, what could be the reason? What do you think ?

[mon2]

Re: Advantech DAC-BC05 Power problem

My suspicion will be with the RAM.

[Per Hansson]

Re: Advantech DAC-BC05 Power problem

Looking at U6 it seems burnt, what could be the reason? What do you think ?

Welcome to Badcaps!
It let out the magic smoke, electronics don't work when the magic smoke escapes
Seriously though it is hard to tell, but a guess could be one of the black tantalum caps is shorted, or one of the mosfets.
It is unlikely that just the IC burns up without some external reason like listed above...

[andrestecno]

Re: Advantech DAC-BC05 Power problem Updated

I replaced the Isl6537acrz and the R257 and now it turns on and works. There is a problem when starting, colored dotted lines appear and last a while until they disappear. Anyone know what can it be ? attached video.

[mon2]

Re: Advantech DAC-BC05 Power problem

My suspicion will be with the RAM.

[alejandro22]

I have the same problem, in q5 I have no voltage, I changed the double mosfet, and it starts but I notice that the mosfet heats up a lot

[mon2]

If the mosfet heats up, remove all power -> measure the resistance to ground on each pin of this mosfet. Someone is placing a heavy load on the mosfet to raise the temperature through a low resistance.