Thanks for your input, I did contact zeusbtc's main branch china, and they told me quite a different story, not saying yours is wrong, but I think this one actually makes a lot more sense.

To summarize that article, they simply imply that if all temp sensors of all hash boards can't report their temp then it's a PSU problem ( not a very common issue), if however less than 3 boards 'normally 1' hash board shows the temp sensor error, then the problem is one of the chips/heatsinks and not actually the temp sensors.

The reason why I am 99% positive about the chip theory is due to the fact that the chances of FOUR sensors going down at once are very very very unlikely, those sensors don't produce much heat if any, they are located across different areas, I am not saying they will not fail, but highly unlikely for one of them to fail, let alone FOUR of them.

To strengthen this point further, based on the article sent to me by zeusbtc, they suspect that the bad chip is usually the first chip, so we tested a T17 board which was giving us the 4 sensors error by putting some pressure on the heatsinks of the 1st chip pushing them down really hard, i learned this method from a video on youtube on fixing S9s boards where he pushes his finger against the heat sink to see if it reports voltage, just kind of making sure the chip is actually in contact the board and the heatsink is in contact with the chip, as naive as it may sound to you, the board DID work and all temps are being read perfectly.

I, of course, don't expect this to last forever, it's a matter of time before the heatsink becomes loose again and we go back to square zero, but at least we are now pretty close to determining the exact problem of this common problem, and once I have physical access to that boards, I will remove that heat sink and put it back, but for now, all of this is done remotely with the help of a friend.

Anyone who has the same problem, please try the remedy, also keep in mind that it may not always be the 1st chip, but if you have a multimeter that reads diode's resistance you can easily identify the bad chip by measuring the heatsink against RST as shown here.