Black then green screen

Hello. I just got a Tablo Dual HDMI the other day, setup was simple. But here’s my problem: every few minutes, the screen turns black for a few seconds, flashes green, then back to the program. It did this even during setup and as you look through settings, etc. I think I have a defective Tablo? Have you all ever heard of this happening before? The audio isn’t affected when this happens. I am using the ethernet connection. I have a 2TB Seagate USB HD for the DVR. It is also new. And, I get 60 channels when the antenna is straight to the TV but only 56 through the Tablo. It will not get the local PBS station, even though it’s at 90% plus on three other tv sets in the house.
I’m using a Steren ANT-UHF 16/PLEG antenna, about a 40 foot run of Quad shielded RG-6 to an older Radio Shack amp then to a 4-way splitter and on to the 4 TV sets in the house. The 3 sets in the bedrooms all get great signal strength. The big screen set in the family room doesn’t have a built-in tuner, hence the Tablo, but only gets 56 channels, all of them full green circles. Looked like a decent unit and we don’t need the quad tuner.
I do have an attenuator but haven’t tried it in line yet, as it seemed to get a little bit better when I installed the RG-6 with new connectors on it.
Thanks in advance,
Guy in WNY
2021-04-17T04:00:00Z

You may be correct in your assumption that your Tablo is defective, but have you tried a different HDMI cable between your Tablo and TV? Also, you might try a different HDMI port on your TV just to eliminate those items as possible sources of your problem.

My system description was incomplete. The Tablo plugs in to an RCA Home Theater on it’s HDMI 2 input (which used to be the DTV satellite box), the HDMI 1 input is the Blue Ray player. Audio from the TV comes to the RCA via an optical input. The TV set itself has the RCA on HDMI 1, Firestick on HDMI 2, HDMI 3 is open, and the laptop is on HDMI 4.
I’m changing that today so the Tablo will be on TV set HDMI 3. Will also be using a longer HDMI cord for that as the one that ships with the Tablo is sort of short and wont reach.
I did a restart on the Tablo today then a rescan and picked up 4 more channels on the guide, but this new channel is too weak to decode a picture.
Still no PBS however.
Guy in WNY

@guyinWNY Please do give that new HDMI cable a try. It sounds like perhaps the one you were using is damaged.

I’ve replaced the HDMI cable and changed from the RCA home theater to direct into an HDMI port on the TV. NO MORE BLACKOUT/GREEN SCREEN!
I put the Blue Ray direct to the TV also. The RCA unit is now only for the audio from the TV via optical.
Still no PBS station, though.
How does the Tablo scan for channels? I have to put in my zip code, so if it thinks my local PBS is out of market, will it not load it? What about all the Canadian stations I get from Toronto on my other TV sets? Will the Tablo decode them or block them as they are out of market for my location - even though they come in full strength here in WNY?

The only thing the Tablo uses your zip code for is guide data. The channels available during a channel scan should be strictly based on what you can receive with your antenna.

Thank you for that answer,
Here in WNY, north of Buffalo and east of Niagara Falls, so far I have found a total of 24 stations for a total of 74 channels, Of course, some are repeats, but I’ve only searched out the S, SSW, SW, and NW directions. I’m going to try E and SE later today. I’ve seen great reviews on Televes Avant X antenna combiner/amplifier that takes several antenna inputs and combines them, and allows you to select which antenna to use for which channel or even assign a new channel number if you have 2 stations on the same channel. It uses either WiFi or Bluetooth to connect to your cell phone to control it. Used to take a rack of equipment at a system head end to do that, now you can do it from your cell phone! But it is pricey. They do offer a less expensive dual input combiner/amp with AGC. Maybe that will be all I need.

Well, I still can’t get PBS. I"ve restarted the Tablo, deleted the user cache, done rescans, etc. Still no PBS. It’s at 97% on the other TV sets. Any thoughts?