This 12 Pro came in for no power.
USB Charging was like 0.44A
When you boot from DCPS, the current draw would jump up only a little, like 30mA at most, then back to zero & repeat. Sometimes, it would just stay at 0 to 2mA
I split the sandwich & it booted!
I put it in the sandwich jig & no power. Back to same symptoms
So went back to top board only & it went back to the same original symptoms.
I was trying to rule out the bottom board issue, but it had the same symptoms as when it came in.
Putting pressure on the whole top board then trying to boot again, it booted! So the issue is very sporadic. But I also was fearing the issue was the CPU.
Tested another bottom board & back to dead. Tested top board only & it booted. Wiggled the top board only & it stopped booting.
This made me think... something must be loose. I removed the shield around PMIC, as there are lots of coils around it & started poking them all. Almost none are underfilled on this model. All were good
I then see there's a coil near the CPU, L4200, on LX_SYS_BOOST and sure enough, it popped right off. Just a very light poke, it broke off.
Tested again & it was doing the same symptoms as the beginning.
Replaced it from a donor & it booted. And even after wiggling and twisting the board lighty, still boots! So it's solved.
Reballed the sandwich & invoiced the customer.
I made a quick little video about it, which you can see here: https://www.tiktok.com/@vcc_board_repairs/video/7142677806932036907
🙌
If you have a Seek Thermal Cam, you're missing out if you don't have a VCC Seek Stand: https://www.vccboardrepairs.com/buy-seek-stand
Injured Gadgets just got these back in stock, so get them while you can!
It can take us a while to build these out sometimes, so they're sometimes out of stock for a while, but we're working towards always having inventory ready to build more as they sell out.
This stand makes using a thermal cam so easy. So much better than any other thermal solution on the market.
It allows you to get real close up (using my Macro Lens), and easily find where the short is coming from.
Plus it's hard free, so you can have your hands free to try to boot the device from DCPS, while having an image that is in focus & not moving around.
You can even record a video through the app, while you inject voltage into the short, so you can go back & see exactly which component was it that was heating up.
Save yourself lots of time by getting a Seek Cam, Stand & Macro Lens! ...
Anyone who is doing game console repairs, knows how many screws you need to remove to access the motherboard.
Especially the PS5, with the 5,000 screws or so.
If you don't already have an electric screwdriver, GET ONE ASAP.
🌟 Cordless Screwdriver with T9 Bit: https://amzn.to/3E5duCj
🌟Extended T9 Bit: https://amzn.to/3c4YJac
It's rechargeable through micro USB and allows you to easily swap the tips out. You can also fold it to be straight or L shape.
Let me know below if you are already using an electric screwdriver 👇👇
I got an iPhone 15 Pro mailed in from New Hampshire for Data Recovery. The front & back were smashed pretty bad.
Took the phone apart & found the bottom board was dented pretty bad
Separated the sandwich to just the top board only and found I had a short before prompt to boot. Tracked it down to a shorted C4222 on PP_VDD_SNS_BPIC
Removed the bad cap & I still had a short. Found the next short on C3499 on VDD MAIN
After that, no shorts before prompt to boot. So I thought that was it...
Well I was wrong. There was a 700mA short after prompt to boot.
Looking at the board under the thermal camera.. heat was coming from the NAND. Although the NAND looked in very good condition with no signs of physical damage. See first pic.
So I decided to remove the NAND to check further.
Without NAND, no short. It would just boot to DFU mode
Closer inspection of the NAND, I found there was a small crack running along the side wall.
When the NAND is cracked, it's GAME OVER. There's no way to ...
I got this Samsung S22 Ultra for Data Recovery. The display connector had some water damage that caused a short on the FPC
After removing the FPC, I found the short was within the layers.
I tried digging it out & it worked, but after placing the FPC back, the short came back.
These are really annoying lol
So I've offered to do a CPU Swap & waiting for the customer to reply 🙏
