Hello,
I was given a broken RPi4B (8GB model, revision 4.9 from week 38 of 2023, it seems) with both the PMIC and the VLI USB chip dead, with visible damage marks and a short on the 1.0V line. I desoldered both of them and replaced the PMIC with a brand new DA9090 from the Pi Hut. That short is now gone.
However, the Pi won't boot and instead blinks the ACT (green) led with a very high frequency. I found out that the 1.8V line is shorted too, which may have slipped past my initial check. However, after removing the DA9090, the short is still there, so the PMIC is not the culprit.
Does anybody know what's running off 1.8V volts?
I can't find anything connected to that line, besides some passive components close to a 54Hz crystal on the back of the board, near the SD card.
I've tried to remove and test a handful of passives connected to that line (in my only working RPi4B) to no avail.
Thanks!
I was given a broken RPi4B (8GB model, revision 4.9 from week 38 of 2023, it seems) with both the PMIC and the VLI USB chip dead, with visible damage marks and a short on the 1.0V line. I desoldered both of them and replaced the PMIC with a brand new DA9090 from the Pi Hut. That short is now gone.
However, the Pi won't boot and instead blinks the ACT (green) led with a very high frequency. I found out that the 1.8V line is shorted too, which may have slipped past my initial check. However, after removing the DA9090, the short is still there, so the PMIC is not the culprit.
Does anybody know what's running off 1.8V volts?
I can't find anything connected to that line, besides some passive components close to a 54Hz crystal on the back of the board, near the SD card.
I've tried to remove and test a handful of passives connected to that line (in my only working RPi4B) to no avail.
Thanks!
Statistics: Posted by cloppy007 — Sun Jun 01, 2025 8:02 pm — Replies 0 — Views 20