I desoldered the regulator and the CP86 capacitor, took measurements between ground and PT24, and there’s a short. I’ve done some research, and this is very bad news. There’s a high probability that the SoC is shorted, thus ruling out any possibility of a viable repair.
The voltage measured for the good board is indeed quite different from yours.It is indeed possible that the short circuit of the SOC caused this component to be damaged.
And what is PT24?
Sorry tp24 its test point 24. The regulator output line
Given the short circuit between ground and TP24, can we conclude that the SoC is dead and the board is irreparable?
Yes, in that case, this might directly damage the SoC. You can contact the merchant to arrange for a factory return and repair.
I’m not going to let this go unresolved. I just ordered the regulator online; I have to wait a few weeks for it to arrive before I can try soldering it and see what happens. I know the chances are slim, but I’m not going to let this opportunity pass me by just because I didn’t buy a regulator that costs less than a dollar.
In a few days, I’ll post whether the board is definitely dead or if it’s working again.
Alright, the replacement regulator arrived. I soldered it on, but the fault definitely persists. The new regulator behaves exactly like the original one—same voltages, it gets extremely hot, and the board shows no signs of life. I think my repair attempt has reached its end. This is my second bad experience with Banana Pi. The first was with the BPI-WiFi6 router; when I got it, the performance left much to be desired, with no OpenWrt updates and no official support for the Triductor TR6560. The WiFi was unstable and the project felt abandoned. Even so, I gave the BPI-R4 a chance, and what I received was a paperweight. I’m quite disappointed, and in case anyone asks, I wouldn’t currently recommend anything from BPI for your projects. This is where my journey with BPI ends. On paper, it seems like something great, but the reality I’ve experienced is totally different. I managed to get a refund from the seller, but that doesn’t change my disappointment regarding these boards.
@FreddyS Your R4 is dead on arrival ?
If that’s the case, either get a replacement or refund. The latter seems to be what you opted for. Problem solved. Bad apple does happen off the production line or along the logistics pipeline even for Apple products.
If you attempt to repair the R4 by yourself, you should be really good at electronics. Nobody could help other than providing you with inspiration for diagnosis.
R4 is good value for the money. OpenWrt support is less than ideal in my experience. Hence, I’ve to port many patches from MediaTek’s feed myself. You can’t shift the blame on software to Bananapi. Or else the total cost of ownership, say of R4 will be much more expensive.
Yes, these are all inevitable issues with the product.