TV backlight LED strips - zener diodes?

[Peabody]

A friend's Samsung TV (UN55HU6840FXZA) began to fail at turning on the backlight when the TV was first turned on.  It had audio, and passed the flashlight test, but no backlight.  Then after minutes to hours, the backlight would suddendly come on, and would stay on until he turned off the TV for the night.  When it wouldn't come on after waiting all day, he brought it to me.  But of course, no sooner than it arrived, it started working perfectly again, and it's tough to diagnose a problem when it's working perfectly.  So I'm stuck.

But in researching this TV, I find that it has 91 LEDs in series. If one of them fails short, there's no problem other than the loss of the light from that LED.  The others still work, and if the LED brightness is current controlled, there isn't even any additional stress on the remaining LEDs.

But if an LED fails open, no current can flow, and the entire string goes dark.  It seems to me that manufacturers could deal with this by putting a zener diode across each LED - one with a moderately higher reverse voltage than the forward voltage of a working LED.  So if one LED fails open, the spice would continue to flow, as it must.

It turns out that the connections between the LED strips and the backplane they plug into are known to go intermittent for whatever reason, and that may be the problem with this TV.  But it could also an individual LED's connection to the strip, the power board, or the main board.  I just can't tell until it stops working.  But I wanted to ask about the zeners because it seems to be a completely workable solution.  But perhaps LEDs always fail short, so adding zeners wouldn't make any difference.

[TheMG]

It would be doable, of course the zener diodes would have to be able to dissipate the same amount of power (actually, slightly more) than the LED it is bypassing.

However, as manufacturers try to shave off every penny they can from the manufacturing cost of consumer products, there's no way they'll do something like that.

You're right that most of the time LEDs fail short, though they can also fail open especially if they are the type with bond wires, the bond wires can sometimes break from thermal cycling. However I do believe manufacturers are leaning more toward "flip chip" LEDs these days which have no bond wires to avoid this particular problem.