# Need help identifying a circuit board chip

#### Xcalknight

Joined Dec 18, 2020
4
hello. First time I’ve posted here. I’m no expert but I dabble in electronics and fixing stuff here and there. I burned up one of my monitors by accident. It’s the PortKeys P6 4K HDMI Monitor. PortKeys said their warranty doesn’t cover this type of damage so I’ve decided to fix myself. I’ve attached a photo of the part that’s burned up as well as several other photos of the board itself. I wish to order a replacement chip, if I can, to replace what looks like the power regulator. As you can see, two of the legs burned up. My idea is to de-solder the chip and replace it. Any advice on how to identify the chip used here and I could use some insight as to if any experts think that any additional damage could’ve been done further down the line. If I’m posting this to the wrong board, please met me know and which board I’m supposed to post on and I’ll correct the error immediately.

Thanks and happy Holidays everyone!!

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#### jpanhalt

Joined Jan 18, 2008
11,087
If it has any sort of programming, which is likely, you're wasting your time and money. That is, if you replace it, you still won't have and can't get the program.

Lesson learned, hard.

#### Chris65536

Joined Nov 11, 2019
270
I'm taking a wild guess that it's this buck converter. It could be a different part, but the MP at the beginning identifies this as the manufacturer. There is a very good chance though, that this device only failed due to something else shorting out downstream . It also looks like a really difficult soldering job, which I would not attempt.

#### jpanhalt

Joined Jan 18, 2008
11,087
OK, how about an arrow to indicate to which chip you refer. I was referring to this chip:

#### Xcalknight

Joined Dec 18, 2020
4
OK, how about an arrow to indicate to which chip you refer. I was referring to this chip:
View attachment 225284
My mistake - you're right, I should've been more specific. I've circled the chip I meant. It's been burned up and is the one I'm trying to identify. I don't think they sell this board anywhere either - but if anyone can find just the board for sale, that'd be awesome but I'm pretty sure it's custom made by PortKeys.

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#### Xcalknight

Joined Dec 18, 2020
4
I'm taking a wild guess that it's this buck converter. It could be a different part, but the MP at the beginning identifies this as the manufacturer. There is a very good chance though, that this device only failed due to something else shorting out downstream . It also looks like a really difficult soldering job, which I would not attempt.
This certainly looks like the correct part. It burned up because the manual says it can handle 7-24 volts. I put a 13.5V 6A adapter on it and poof it burned up. Duh! It was a very moronic thing to do. I think 12V 1A would've done the trick but that 13.5V adapter was so much more convenient. Yes, lesson learned - however, it didn't short out due to something down the line. It short because the regulator couldn't handle the amperage.
Chris, why wouldn't you attempt this solder job? The whole unit itself costs $160. PortKeys warranty doesnt cover electrical damage so that's why I popped it open. That part you suggested was ~$2.00. If I can successfully remove the old regulator chip and replace it with a new one, I've saved $160! If not, spending the$160 again isn't going to break the bank - just kinda hate buying things again and just because of one little piece failing. Hopefully, the rest of the components still work.

#### jpanhalt

Joined Jan 18, 2008
11,087
The current capability of the supply should have made no difference. It is the voltage.

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#### Chris65536

Joined Nov 11, 2019
270
Chris, why wouldn't you attempt this solder job?
I think it's beyond my soldering abilities and equipment. That also might not be the right part#. There could be others which end with "8" that Mouser doesn't list. Or it could actually be a "3" which brings up several other parts. So I wouldn't take my guess as the answer, but a starting point. Maybe you can find a picture of this board out there somewhere, and try to read the number off an intact chip? But the fried buck converter might still just be a symptom, not the root cause. Good luck if you do try it, and let us know how it goes.

#### Xcalknight

Joined Dec 18, 2020
4
The current capability of the supply should have made no difference. It is the voltage.
I'm not sure what the regulator's capabilities are though. I'm just letting you all know what the instructions said. I thought "if the manual says it can handle anything from 7v - 24v, then a 13.5v should be fine and it would only take the amount of amps it needed. I suppose I was wrong? Not sure; all I know is that the chip got fried and now I have a monitor that won't work unless I can replace the chip (assuming that's all that's wrong).

Thanks though. I think I'll be sticking to trying to only supply it with 12v 1a power supplies.

#### jpanhalt

Joined Jan 18, 2008
11,087
I'm not sure what the regulator's capabilities are though. I'm just letting you all know what the instructions said. I thought "if the manual says it can handle anything from 7v - 24v, then a 13.5v should be fine and it would only take the amount of amps it needed. I suppose I was wrong? Not sure; all I know is that the chip got fried and now I have a monitor that won't work unless I can replace the chip (assuming that's all that's wrong).

Thanks though. I think I'll be sticking to trying to only supply it with 12v 1a power supplies.
You are not wrong. That is the correct interpretation.
1) Just because it happened sequentially does not mean the former caused the latter. There's a Latin say for that: post hoc ergo propter hoc.
2) There could be other causes, such as the voltage was actually higher than stated. A lot of inexpensive supplies are not regulated put out more than rated voltage when the load is low. Another possibility is that the supply had reversed polarity. If it was a barrel plug, the center is not always positive.