In the past 6 weeks, we've had 5 Mikrotik 900 / 9hpn devices lose their TX signal. Tower side, customer side, multiple towers, though 1x was the same customer twice. We gave that one a new power supply. In the couple of years before that, we lost 3 to that same thing.

To be clear: it'll go from the TX/RX being -50/-53 to -50/-83 from the AP side or something like that -- it's like the failed unit's transmit side just dies.

I'm just wondering if anyone knows what might be causing this? I'll be taking one apart shortly to see if I can swap parts from other failed radios, but if there's a known trigger, I'd like to avoid losing more.

Thanks.

What's the weather like where you are? If it's like mine, then your radios could be biting the dust because it's hot and sunny and the Metals are painted dark colors which makes them even hotter.

Actually the opposite: It's cold. 0-15 degrees. Come to think of it, all of the radios have failed in cold weather, though the previous failures were only on a tower and don't think it was as cold, but we had to make temporary workarounds due to weather.

We have historical monitoring on radio temps, so I'll look into that. Thanks.