# TV lift only part rises



## WurliTzerwilly (Dec 29, 2015)

Hi all. I just joined this forum.

I have a TV-Lifts TVL7-Series-780 tv lift mounted below floor level, to lift a 55" flat screen. It's about 3 years old and has been working OK until yesterday, apart from occasionally getting a little noisy when rising. To cure that I sprayed the outer casings with Bostic Top-Cote which I use on woodworking machinery. It's silicone based and is inert. Keeps the lift sweet.

Yesterday my wife used the lift as usual and it will only rise part way. The base of the TV stops exactly at floor level and this is repeatable. This unit has a wired switch as well as a remote and it does the same thing using the wired switch, so not a remote issue. The lift lowers and stops exactly the same as normal.

There are no bad sounds coming from the unit and I can't find any obstructions. All fixing bolts seem to be in place and tight. I've switched the controller/PSU off for an hour or so in case it was a software reset issue, but it's just the same. I've also checked all of the user connections.

The unit also has a memory position which allows it to stop at a pre-determined place between fully up and fully down, which was set much higher than the current (incorrect) stopping place, so I don't think it's that. The "full-rise" switch overrides that anyway.

Does anyone know how the lift determines where it is in its cycle? Does it have a "lowest possible" limit switch and a "highest possible" limit switch? Does it count pulses from an encoder within the unit or an encoder strip?

Unfortunately, the supplier is on vacation until January 4, so I can't ask them (if they know), but I'd like more info before I start dismantling things, especially if the fault is in the control box, which may need replacing.

Any help would be appreciated.

BTW I'm in the UK.

Regards,

Alan.


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## gregzoll (Dec 25, 2006)

Upper limit and lower limit switches are to tell the mechanism when to stop. If they go bad, yes there could be an issue.

Unless there is a control board, there is no need to unplug for an hour.

I would remove the tv from the lift and check to make sure nothing got into the track area as you cycle it up and down.

If it works fine without the weight of the tv, then most likely the motor or lift mechanism is worn out.


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