Electronics → What exactly is an "AK33248B8"?

I have a LCD monitor that has been turning itself off and back on after running for a few minutes. I opened it up and found that what looks like a power regulator labeled AK33248B8 has been getting extremely hot and has been failing. It hasn't burnt up, and still seems to work okay when cool, but the designers of the circuit board didn't make enough of a provision for heat sinking. There's only a small patch of PCB about 1/2 square inch provided to dissipate heat from the device's mounting tab. Unfortunately the component is a rather small SMD and there isn't really any room to stick a heat sink on it so cooling the existing part isn't viable.

I have plenty of larger power regulators on hand, but I can't seem to find a datasheet or specs for this particular component so I'm not sure what I can replace it with. Any assistance from somebody who knows anything about this component would be greatly appreciated.

P.S.: I can get photos of the part if it would be helpful.

Search brings up absolutely nothing (exc. this post ) so post a picture.

I've seen chips marked with the AK prefix that were Asahi Kasei: »www.asahi-kasei.co.jp/akm I took a quick look, but I didn't see didn't see 3324 in the live or discontinued product list. I also don't think they make voltage regulators(at least not under the AK brand.) So the picture might be helpful.

Here's the pictures.

I still haven't had any luck in my searches. I guess the next step would be to try and probe voltages, assuming the part is still in spec.

What brand and model of monitor is this?

Looks like a regular linear LDO regulator.

Replacing it will probably have little effect. You can add a heat sink to the large bare area. I have used a piece of copper soldered to the area.

Could be a problem elsewhere causing too much current draw.

It's a Mag Innovision LT765b.

That's a well cooked PCB.

Anyhow, you should be able to determine input/output, GND, and voltages, and put in a TO-220 or so part with equivalent specs.

And at the same time, you may want to look into if something is drawing too much current.

Look for the service manual - that might give a hint.

Actually, the PCB itself isn't really damaged at all, it's the sheet of insulating plastic that got, well, not scorched exactly, but really hot and discolored and warped.

I managed to trace and probe what this thing does. It's a 5v to 3.3v regulator that supplies power to an MX10E8050 cpu and a MASCOT VPRL LCD driver chip. Those are the only things drawing power from it. I figure that the problem is one of either the cpu is sinking too much power out of one of its I/O ports, the VPRL is doing the same, or the input voltage is actually too high indicating the upstream 12v to 5v regulator has a problem.

My guess is that the regulator was designed to run with a paper thin margin of its maximum ratings, and an aging component got enough out of spec to push it over. This is one of those annoying situations that only pops up under just the right conditions. I ran the monitor for a half hour out of its case and nothing happened. I guess that being packed into such a tight space when assembled causes excessive heat buildup.

Looks like I'll just have to stick in a beefier regulator, one that I can bolt a heatsink to.

For 5V to 3.3V make sure you use a LDO regulator.

My best guess is that is a 3 terminal regulator, (as others have said) and you have something failed past it causing it to draw too much current. That would cause it to go into thermal shutdown periodically for protection.

Most likely that part is only a symptom and NOT the problem.

Check the filtering caps along the line you might have one that is on the verge of shorting out completely.

That looks to be a dual package footprint... If you figure out what the part is, might want to bump it up to the larger package.

Look carefully at any decoupling caps. That also looks like it's going to be a multilayer board so it could be taking off in a direction you are not aware of. Troubleshooting this sort of problem is when I really like to have an IR camera, you can actually see slightly warm traces and know where the current is going. I found many a trouble that way.