MacBook Pro A2251 820-01949-A stuck on 5V

[piernov]

There is no new CD3217. Everything is at best pulled and reballed, and at worse fake. The issue is that you don't know which board and which side of the board they come from.
Pull from same location (left side to left side and right side to right side) and reball yourself from a donor with same USB-C ports configuration and you won't have issues.
If that's not enough, instead of manually reflashing the SPI ROMs (you can try if you want), you can also pull and reball the SPI ROMs, again from the same location.

[mferna14]

Thanks @pienov for the detailed explanation & for the SPI ROM re-programming I found this board to solder the SPI ROM on it & re-program them. Easily available on AE & better the spending $165 for that USB tool above which does the same job.

[Stephen]

There is no new CD3217. Everything is at best pulled and reballed, and at worse fake. The issue is that you don't know which board and which side of the board they come from.
Pull from same location (left side to left side and right side to right side) and reball yourself from a donor with same USB-C ports configuration and you won't have issues.
If that's not enough, instead of manually reflashing the SPI ROMs (you can try if you want), you can also pull and reball the SPI ROMs, again from the same location.

What he said, whenever we get a board that is A2251 we just use a donor board for a repair. We have a good few in stock and most of the time it's just one port sometimes two. We always use the exact port for this now. I would suggest looking at what Piernov said.

[mferna14]

A2251 must use the chip from a Donor board. You cannot just replace it with a new chip, depending on the side of the chip, you will need the CD3217 from a Donor A2251 board on the exact location. You may have ruined the board moving forward with a new chip. This particular board needs a DONOR, or you can program the new CD3217 chip based on the location. There is a CD3217 chip reader and programmer for this particular reason.

Dear Buddies., I did a sound & steady research on these chips CD3217B12 replacement on this logic board. I had to repair another motherboard like this 820-01949. One of the CD3217B12 (Small Dot) location U3100_X was bursted but the other U3100_T looked fine. Since I had the time I replaced both new CD3217B12 (BIG Dot). Upon testing the logic board got stuck on 5V. I noticed that this board uses all 4 CD3215B12 (Small Dot). I had some old CD3215B12 (small dot) lying around. So I re-balled 2 chips & soldered back in the location U3100_X & U3100_T. Guess what, all worked fine, 20v perfect & board run like charm. So this side chips do not need any programming. On the other side the 2 CD3215B12 U3100_R & U3100_W (This chip has a round black paper marker on it). I think this is only programmed chip & has to be replaced with the Donor board chip. Just for fun sake I replaced U3100_R with another old chip lying around in my workshop. No Problems at all. All worked fine. My conclusion on this is that ONLY check for the CD3215B12 SMALL & BIG Dot chip, there is difference in these chips & cannot be interchanged as a set. Hope this helps all.