My experience with these units has been disappointing. The first Tablo failed after about 8 months, the second (a warranty replacement) died within just 3 months, and the third (a second warranty replacement) just arrived before the expiration of the one-year warranty period. Based on my observations, I strongly suspect that overheating is the primary cause of these failures.
The top of the unit becomes extremely hot to the touch—hot enough that the metal antenna connector could potentially cause burns. I have it placed on a glass-top piece of furniture, and the surrounding area heats up significantly. While I wish I had a laser thermometer to measure the exact temperature, it’s evident even without precise data that the device operates at an excessively high temperature. My area has excellent signal strength, so I turned off the antenna amplification to help reduce heat, but it made little to no difference.
Since the manufacturer asked me to keep the failed units, I’ve taken a closer look to diagnose the issue. It’s quite easy to pry open the unit from the top, revealing a surprisingly compact design. However, it appears that the engineers anticipated heat issues from the start—about 75% of the internal space is dedicated to a large heatsink. The bottom has air vents to promote airflow, but once the top cover is sealed, heat has no escape route. To make matters worse, insulation was added to the top of the case—likely for fire safety certification or to prevent discoloration—unintentionally trapping heat inside. This design seems counterproductive and, in fact, exacerbates the heating problem.
This third unit might be my last warranty replacement, so I’m taking steps to verify whether excessive heat truly is the root cause. My entertainment system is connected to an APC UPS, so power fluctuations are not an issue. The power supply from the failed units measures around 11.95V DC—on the lower side, as I would expect close to 13V DC under no load. The new unit’s power supply measures similarly, indicating that the power supply isn’t the culprit.
To test my theory, I installed a 50mm USB fan (purchased from eBay) on top of the unit to help exhaust the heat from inside the unit. Initially, I found this to be overkill, maybe a smaller fan will do the job. Also, it was noisy, so I added two 1N4001 diodes in series to the fan’s positive lead, dropping the voltage from 5V to about 3.6V. This is a simple, inexpensive solution using parts I already had. Now, the fan runs at a lower speed with minimal noise—almost unnoticeable. I’ve connected the fan to a separate USB power source to avoid adding load to the Tablo’s power supply; the fan draws only about 0.18 amps, which I believe the Tablo USB port can handle.
The initial results are promising: the unit now stays at roughly room temperature. Will this extend the lifespan of my third 4th generation Tablo? Only time will tell…
