Question regarding ASIC status (Antminer S7)

[faridsharby]

Hi guys,

Why sometimes theres a X mark on my ASIC status? It turns to normal for like every 15 - 30 minutes and then the X mark appears back. I dont see any problem with my hashrate as my hashrate runs almost consistently above 4th/s everytime with the frequency set to 625M. Sorry im kinda new to this stuff and hope to see some helpful explanation from you guys. Thanks!  

edit : 1) when I reboot the system it goes back to normal again but sometimes the X mark will appear again on random position
         2) It appears that it might due to the PSU as when I lower the frequency rate the X mark doesnt appear anymore ( can anyone recommend some good PSU for me?)

[Ahead]

The X is a mark that an ASIC chip on that PCB board is dead/faulty/not_responding.
Each row is a PCB board, and the O/X is the ASIC chip status

[faridsharby]

The X mark goes on and off at certain point. Is it due the faulty board? But I did not see drastic drops on the hashrates..

[leowonderful]

This could be a temperature issue. What are the temperatures like on the board? It could also be a thermal paste issue, in which case a tube of MX-4 can fix. The blade could also just be unstable, unfortunately.

[faridsharby]

Here's the picture of my boards temp..
https://ibb.co/bQZvoa

All of the boards temp never exceed 65 during the whole run.. Yes I was thinking about that also. Maybe need a little bit of cleaning and thermal pasting. But can the psu could be one of the factors? Im using some unknown chinese brand with 1850W.

[fanatic26]

Since the heatsinks are held on with thermal epoxy, thermal paste will do nothing. Also, you will most likely damage your board cleaning the old epoxy off before putting the new stuff on so I wouldnt recommend it. These are not anything like computers in that way.