Expected lifetime of CCFL backlight - Page 1
Forum section: electronics / projects

author: jitter
author_rank: Frequent Contributor
timestamp: May 29, 2016, 09:27:13 am
content: Short version and question:Long story short: I think my CCFL backlight is worn, is that a reasonable assumption after ~10,000 hours of usage?Will LED-backlight do better?Long version:Yesterday I replaced my trusty old Samsung Syncmaster 226cw monitor that I've been using daily for over 7 years now. Not because it was broken, but because after looking at a cheapo newish Philips monitor at my parents' I was under the impression that mine was rather dull in the brightness department while spec-wise it should beat the Philips.Back home I went to up the brightness and contrast, only to find both were already set to the max! Hmm...Googling backlight on this model turned up lots of issues with the 226bw needing new electrolytic caps on the power/inverter board. Now that board is also in my 226cw and goes under the type IP-43130A and causes a rash of hits when you google it (mostly people selling replacements).But as you can see from the photo of the unit in my monitor, the caps look just fine. No bulging. Some pictures on the net show this power board with failed CrapXons, but these Samwhas are probably a bit better quality. I tested them with an LCR meter with ESR capability, and they measure beautifully.Calling up the service menu (set brightness and contrast to 0, then hold the enter button > 5 seconds) shows that the usage is nearing 10,000 hours and 30,000 cycles.All this combined led me to believe that it is actually the CCFL ageing rather than any other defect. Hence my question if this is a plausible assumption. What would normally be the expected lifespan of a CCFL backlight? And would LED backlight live longer?

author: wraper
author_rank: Unknown
timestamp: May 29, 2016, 09:45:26 am
content: I usually see displays running at max brightness, often this is default factory setting. Not only it is bad for the eyes, but prematurely wears out the backlight too. If brightness is set to reasonable level, backlight will last a few times more. As of capacitors, Samwha WB series were plagued with bulging issue but as caps are different series, it should be fine.

author: retiredcaps
author_rank: Super Contributor
timestamp: May 29, 2016, 02:15:50 pm
content: Quote from: jitter on May 29, 2016, 09:27:13 amI got a 226BW for free. It was indeed bad caps. $5 later in new caps, it is my favourite monitor in the house.QuoteWhen I was fairly active at badcaps.net, I usedhttp://www.ccflwarehouse.com/faqs.htmlas a guidelineQ: What is the typical life of a CCFL lamp?A: The typical rated life of a CCFL backlight is 20,000 to 40,000 hours.QuoteOver at badcaps.net, we see a lot of TV LEDs failing due to settings at 100% brightness. Individual or many LEDs will fail after about 1 year usage. Reducing brightness helps, and of course the quality of the LED, but at least with TVs, it seems like sooner or later LEDs will fail.PS. Most of my computer monitors at home are set for 35% +/- 10 brightness and contrast depending on the monitor and its location wrt to windows, sun, etc.

author: retiredcaps
author_rank: Super Contributor
timestamp: May 29, 2016, 02:18:15 pm
content: Quote from: wraper on May 29, 2016, 09:45:26 amI call it store demo mode. It is used to wow the consumer and then die just after factory warranty.

author: sarepairman2
author_rank: Frequent Contributor
timestamp: May 29, 2016, 03:29:34 pm
content: tick tock your time is up

author: retiredcaps
author_rank: Super Contributor
timestamp: May 29, 2016, 03:46:38 pm
content: My 226BW is set to 10 brightness and 15 contrast. It has 4047 hours on it with 43646 cycles. I probably used a 1000 hours on it? So the original owner only used it for 3000 hours maybe before the caps died?

author: amyk
author_rank: Super Contributor
timestamp: May 29, 2016, 03:54:37 pm
content: Lifetime is inversely proportional to brightness. I have some CCFLs in a pair of 10+ year-old monitors that are still bright enough; I set the brightness to 0 when new and bump it up slightly over the years to compensate. One is at 30 and the other is at 10 (out of 100).