The other day i recieved another LED backlight kit identical to the one presently in my Cintiq 24HD, but it snapped in the mail as the seller somehow thought it was ok to mail inside a long card rectangular box, no packaging whatsoever, i recommend avoiding ebay for your kits even though its cheaper, on aliexpress they mail it in a PVC pipe, or cardboard pipe, or the strips come in tubes with the driver and surrounding packaging going in a bag or box or something.

Anywho, i began testing them and to my shock, sort of, the LEDs sit comfortably between 600 and 800ma, which is reached at about 9.5v or so. EACH, up to 800ma EACH. While i have not tried to measure the driver output, the input hangs around 500-600ma regardless of the voltage. It seems to cut the excess voltage above 10v as heat, as ive mentioned in a previous entry.

But the shocking part here is, if you remove one of the strips from the driver, the input remains the same, and the brightness of the remaining LED intensifies, meaning that the driver is running the LEDs in parallel, not independently. Ordinarily the effects of something like this would be catastrophic, combusting LEDs since its pushing the same current through one as two, but heres the funny thing. In order to compensate for this situation, rather than putting two current controllers on the board, the LEDs used are rated at over twice the total current. In other words, should 1 LED strip fail or disconnect, the remaining one is still capable of running at the same power level, which is about 5-6W now that i look at things.

Disregard anything i may have said before about the actual output, considering the heat generated and the fact the LEDs run the same brightness with a driver supply voltage of 10v as 20v, the LED strips as is by the driver will be powered with 250-300ma, at about 9V, each, probably 250ma though, totalling at 500ma, 9V, so, 4.5W of actual output.

The LED strips however each can operate at about 700ma, which was about 9.5-9.8v, i didnt run it higher but around 700ma the increase in light was less significant per power increase, so i think 600-700ma is a safe output provided you use a thermal adhesive strip to stick the strip to the monitor case, otherwise it may well overheat.

The important thing to take from this if you are getting tired of reading is that the LED kits, 540mm strips can take a little over double the factory rating, and so, its best instead that you acquire two constant current drivers , preferably tunable ones, and set them to at least 500ma, one for each strip. Doing so you can double or almost triple the display brightness from default.
My next and hopefully last entry on this project (besides another final summarizing post) will be an experiment to see if the voltage of the driver can increase enough to deliver enough power that a constant current driver can just be stuck inline with the existing driver, between the driver and LEDs, dimming would probably work to some extent but the LEDs would run at a correct output. The driver will raise its voltage until about 500ma total is being supplied, if the input is 24v, this means a potential 12W, which should be enough to power the LEDs at a suitable brightness AND have monitor controlled dimming AND the driver should not be overheating.

In the mean time the quick and easy solution is to go and grab two step down converters or constant current drivers, and set them to around 700ma, or wherever your LEDs seem to be peaking, if you imagined a line graph of the brightness increase VS power increase. The point the brightness increases less with power is when you are probably going too far and are generating excessive heat.