When the cr2032 battery in ps4 runs flat it will no longer keep the kernel clock running and the clock will be set to year 1970, causing 30391 error when you try to launch anything (including retail discs). This isn't an issue for people on latest firmware as the kernel clock will be synced with psn server. However, on older firmware this will clearly cause problems, as you can't access psn network. IIRC setting kernel clock only works on 5.05, and on 6.72/7.02 we are just bypassing the error instead of fixing it. So I figured instead of waiting for the RTC battery to die and cause problems, I can replace it before it dies and my ps4 will be good for another 5 years.
Here's the steps:
1. Fully disassemble your ps4 and take out the motherboard;
2. Locate your RTC battery and measure its voltage with multimeter. My is at 3.09V but I'll replace it anyway.
3. Connect the PSU and plug it in. You only need to connect the 4 pin connector.
4. Measure the voltage before the tiny diode (which prevents charging the cr2032 battery when ps4 is plugged in). If your ps4 motherboard is powered you'll get a reading around 3.2V. Make sure the motherboard is powered before removing the old battery!
5. You can replace the battery now. I'm using an IKEA battery, quality is ok IMO.
Here's the steps:
1. Fully disassemble your ps4 and take out the motherboard;
2. Locate your RTC battery and measure its voltage with multimeter. My is at 3.09V but I'll replace it anyway.
3. Connect the PSU and plug it in. You only need to connect the 4 pin connector.
4. Measure the voltage before the tiny diode (which prevents charging the cr2032 battery when ps4 is plugged in). If your ps4 motherboard is powered you'll get a reading around 3.2V. Make sure the motherboard is powered before removing the old battery!
5. You can replace the battery now. I'm using an IKEA battery, quality is ok IMO.
Last edited by randy_w,