nicolae
Posts: 3
Joined: Sun Jul 16, 2017 11:15 am

Low voltage with TV Tunner

Sun Jul 16, 2017 11:39 am

Hello.

I have RPI 3 model B and i use it as a HTPC via wired ethernet. Bluetooth and WiFi are turned off.

I run LibreELEC on it and use Kodi for playing media, i also use the Tvheadend PVR client.

Recently i moved my PCTV tripleStick 292e TV Tunner from another PC to this RPI 3, and installed Tvheadend locally on the RPI 3 also.

The major issues that i am starting to have now is the low voltage thunderbolt icon, and frequent buffering while playing TV, especially with the HD channels. Sometimes it does not respond at all and/or freezes for a short period.

I have a 5V/2.5A power adapter, with a 1M 20AWG micro usb cable.

So far i tried to introduce this usb powered hub: https://www.hama.com/00078472/hama-usb- ... dboard-box

But the RPI 3 just freezes when i plug it in while running. And if it's plugged in before powering the RPI 3 on, the TV tunner is not recognised as plugged in. Somewhere in the boot process the TV tunner led shuts down, it's on in the noobs part of the RPI 3 boot.

What should i check?
Should i move to a more powerful power adapter?
A shorter micro usb cable?
Another powered usb 2.0 hub?
A 18AWG micro usb cable? (not sure where to find these)

Thanks.
Last edited by nicolae on Sun Jul 16, 2017 12:30 pm, edited 1 time in total.

drgeoff
Posts: 8765
Joined: Wed Jan 25, 2012 6:39 pm

Re: Low voltage with TV Tunner

Sun Jul 16, 2017 12:27 pm

1. The labels on power adaptors, especially those intended for use as chargers rather than power supplies, are often "optimistic". Providing the rated volts and amps simultaneously is often not possible.

2. Power adaptors do fade, especially cheap switched mode types. The electrolytic capacitor(s) on the output of the rectifier loses capacity over time. Result is inability to sustain the voltage when loaded.

nicolae
Posts: 3
Joined: Sun Jul 16, 2017 11:15 am

Re: Low voltage with TV Tunner

Sun Jul 16, 2017 12:37 pm

drgeoff wrote:1. The labels on power adaptors, especially those intended for use as chargers rather than power supplies, are often "optimistic". Providing the rated volts and amps simultaneously is often not possible.

2. Power adaptors do fade, especially cheap switched mode types. The electrolytic capacitor(s) on the output of the rectifier loses capacity over time. Result is inability to sustain the voltage when loaded.
Hello, and thanks for the reply.

It's actually a 2500 mA adapter (or so it says on the label), i edited my post.
I have measured the output exactly at the adapter end, it's 5.12V when leaving. I remember i bought it especially for the RPI 3, but i never saw it draw more than 1A, is there a lightning bolt icon for the amps ? Is the lightning bolt strictly related to voltage?

User avatar
bensimmo
Posts: 3490
Joined: Sun Dec 28, 2014 3:02 pm
Location: East Yorkshire

Re: Low voltage with TV Tunner

Sun Jul 16, 2017 1:24 pm

What's the model on the adaptor.

nicolae
Posts: 3
Joined: Sun Jul 16, 2017 11:15 am

Re: Low voltage with TV Tunner

Sun Jul 16, 2017 1:39 pm

bensimmo wrote:What's the model on the adaptor.
It's something OEM, no model or brand.

P.S. I think it's best if i buy this: https://shop.pimoroni.com/products/rasp ... wer-supply
or this: https://thepihut.com/collections/raspbe ... wer-supply

Not sure if they are the same product, forgive my confusion then.

dom
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 5171
Joined: Wed Aug 17, 2011 7:41 pm
Location: Cambridge

Re: Low voltage with TV Tunner

Sun Jul 16, 2017 1:59 pm

nicolae wrote:I have measured the output exactly at the adapter end, it's 5.12V when leaving. I remember i bought it especially for the RPI 3, but i never saw it draw more than 1A, is there a lightning bolt icon for the amps ? Is the lightning bolt strictly related to voltage?
You need to measure on the Pi when the system is under load (i.e. showing the warning symbol).
You can measure between 5V and GND on the GPIO header.

The lighting bolt appears when voltage drops before 4.63V.
Not sure if they are the same product, forgive my confusion then.
Yes, they are both the same official power supply (it comes in black and white versions).

Return to “Troubleshooting”