There is microcontroller inside a TV. It has its intenal built-in EEPROM which has around 100,000 write cycles. Maybe because of this less write cycles they use external EEPROM chip like 24C08 which has around 1 millions of write cycle.

Now question is when TV writes its data to EEPROM? When we upgrade its firmware? Or when we delete all the channels (let's say rest factory setting) and search again? Or everytime when we pressed volume up-down, channel up-down, brightness up-don, mute-unmute etc?

 

Now question is when TV writes its data to EEPROM? When we upgrade its firmware? Or when we delete all the channels (let's say rest factory setting) and search again? Or everytime when we pressed volume up-down, channel up-down, brightness up-don, mute-unmute etc?

The answer is - it depends.

Any data that is to be retained across power cycles needs to be written to the EEPROM. When this is done is a matter of "style".

You could write data to the EEPROM whenever it changes, but, as you've mentioned, this could use up the guaranteed write cycles unnecessarily.

It makes sense that a firmware upgrade would be committed immediately. Anything that was maintained in volatile memory only needs to be written before power down if it is to be maintained.

 

I would think it writes everything to EEPROM every time you turn off the power.
Thus if you turned the TV power on and off once a day, the microprocessor EEPROM would be good for 100,000 days or 274 years, likely beyond the lifetime of the rest of the components.
Or to look at it another way, you could turn the TV on and off ten times a day and it would still go 27 years before the EEPROM failed.

 

Most Tv's don't really turn off like the whole TV more like just screen my tv shows up on wifi even when it's off.

My kids unplug about everything in the house they say it saves money which it dose
all these power supply's seem to just sit and waste power.

But I'm sure the rest of the tv wear out before the eeprom
like crutschow said a good 27 years.

 

I have a TV that looses volume, current channel and everything when it looses power. It was a simple analog TV.

The new DTV will actually come on in th eon state if it was on when power failed.

With the necessity to scan channels, there needs to be non-volatile memory.

FRAM is an option, a battery backed up RAM is an option. There are some algorithms used within chips or within firmware that may reduce writes to certain areas.

And yes, you only need to commit to non-volatile memory when power dies.

So, I have an antenna rotator. It does have channel to position mapping. it might write the channel association every time, but I don;t know.

I'm actually not sure what happens. I do know that when the motor quits draw current, the state is retained by the house box.

The rotor position and the antenna position are not in sync when the antenna is moving. It "pretends" to be.

I think it uses PIC processors at each end and not sure what it uses for position. it does have an Index pulse, but I don;t think it tries to sync every time it powers up. The rotor does not have a potentiometer. It's definately optical with limits and an ORG switch at NORTH.

It does however have more than 360 degree rotation. I think it;s more like 450 degrees. This prevents going all the way around on occaision.
The display is restricted to 0-360 degrees. You can input 400 deg.

 

I once built a big system with a bunch of 1990's analog TV's, we constantly changed the channels using IR blasters.

Seemed like the EEPROM wore out in about a year, they would power-up to non-existing channels after a while.

 

I once built a big system with a bunch of 1990's analog TV's, we constantly changed the channels using IR blasters.

Seemed like the EEPROM wore out in about a year, they would power-up to non-existing channels after a while.

In that condition, if the EEPROM is external chip then do we need to JUST 'desolder the old chip' and 'install new' one? Where the firmware stored? Or do I lost firmware too if I removed old EEPROM?

 

In that condition, if the EEPROM is external chip then do we need to JUST 'desolder the old chip' and 'install new' one? Where the firmware stored? Or do I lost firmware too if I removed old EEPROM?

Not so simple.

You would have to know a lot about how the TV worked, more than the manufacturer will ever care to tell you.