Just wanted to share this https://www.thingiverse.com/thing:4124195
HTC Vive Wireless Dual 30mm Cooling Fan.
2x - 30x30x6mm 12v Fans @ 7.5v (Low speed fan resistors I had sitting around)
1x - 1.3 ID x 3.5mm OD DC Jack
This was built due to Grey/Blue screen flashes on the HMD, Falling through the world or slowly losing tracking on the Vive Cosmos during wireless play.
Looking at logs in
C:\ProgramData\Vive Wireless\ConnectionUtility\Log
The HTC Vive Wireless would start with temps reporting
[2020-01-19 17:36:58 +10 0xB70 INFO LOG] M_Temperature=36, R_Temperature=33
-After 20minutes play time-
[2020-01-19 17:56:46 +10 0xB70 INFO LOG] M_Temperature=91, R_Temperature=62
After the modification was performed the log output reported
[2020-01-24 14:45:39 +10 0x4394 INFO LOG] M_Temperature=30, R_Temperature=23
-After 20minutes play time-
[2020-01-24 15:05:19 +10 0x4394 INFO LOG] M_Temperature=48, R_Temperature=49
Both of these were experienced with the same room temperature of 24c and 20minutes of playtime in Beat Saber.
After extended use it originally used to display temperatures reporting
[2020-01-07 18:19:42 +10 0x32B0 INFO LOG] M_Temperature=99, R_Temperature=63
[2020-01-07 18:19:52 +10 0x32B0 INFO LOG] M_Temperature=100, R_Temperature=65
[2020-01-07 18:20:22 +10 0x32B0 INFO LOG] M_Temperature=102, R_Temperature=66
With a grey/blue HMD flicker every few minutes.
This has cut cut the temperature by half and resulted in no drop outs after hours of use.
Cheers