I got over the house with the Roamio-TiVo so I could take a look at the situation myself instead of relying on 2nd-hand info.

The TiVo had been unplugged and off for the last few weeks so everything was cool.

I first plugged the powerbrick into an outlet and measured the voltage at the barrel-jack = 12.0V, good per the 12V@2A brick rating.

I plugged the powerbrick-jack into the TiVo and it booted OK. I used it for nearly an hour, trying to abuse it and get it to fail -- e.g. watching OTA channels & saved videos, starting multiple recordings. The brick got warm but never hot. Just when I was about give up the TiVo suddenly rebooted, showing me the TiVo "Welcome! Starting up..." screen (that never progressed beyond that), while all four front-panel lights (green=power, yellow=remote-activity, red=recording, blue) continuously fast-flashed. It remained in this state until I unplugged the TiVo.

When I went to unplug things, I found that the power barrel-jack into the TiVo was hot/very-warm. The brick itself at the AC outlet was still only warm. I again checked the voltage at the jack = still 12.0V. I also popped the TiVo lid and don't see anything on PCB-top that should be getting the jack hot (unused rear connectors, power & data cables to harddrive).

I've seen plenty of powerbricks die/"fade", with a drooping voltages when the brick (capacitors) ages & gets hot. This isn't behaving exactly like that--the brick is only warm and it's the barrel-jack end that's hot (most likely something hot inside the TiVo, conducting heat to the jack & cord). With the jack no longer connected to the TiVo I wasn't catching a drooping voltages, although by then there would have been no current draw. I could replace the powerbrick and see what happen. The jack measures as a common 5.5mm-OD, 2.1mm-ID, 12V-pos-center.

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Last week I ordered a replacement Roamio but unfortunately found when I went to install it today that I had accidentally ordered the CableCard-only Roamio Pro/Plus model. So I'm going to need to return that, to exchange for a Roamio Base OTA model. Assuming a new power brick doesn't fix this Tivo's problem.


Tivo_Roamio-base_TCD846500_power-jack.jpg

I bought a replacement power brick (12V3A, same 5mm barrel jack & polarity) and booted up the Roamio. It's been running for the last two hours with 4x simultaneous recordings or 3x + random program guide shows; no shutdown or reboot, no flashing LEDs. The brick and jack into the Roamio are all cool.

However, I had the unit's lid off while I was doing this and noticed that the 35mm x 10mm internal fan is not spinning. I pulled its 2pin connector and verified 12V at the pins. So the fan seems to be dead. It's possible that the problem was the unit was overheating -- that's the only way I could see the barrel-jack from the brick getting so hot since an IR meter shows the hot spots are the unit's center black heatsink and the metal grids over the tuner elements, both far away from the jack.

So it seems like the next action is to buy and replace the small internal fan (with too much effort required to access the two bottom screws on the fan--when I put the new one in I'm going to *only* screw in the top two screws for if & when the fan has to be replaced again). Then run the unit with the top reinstalled and see how it goes. Either that, or run with the lid off, relying on convection cooling.