If i haven’t provided links before, its because links on aliexpress and ebay expire, they usually cease to work if a listing sells out for too long before its relisted, or if the listing is cloned instead of relisted, the url changes. I wont be updating this URL if it ever expires or becomes invalid.
When searching for a backlight kit, search “540mm LED backlight replacement”, all kits are exactly the same, or at least ive never seen one different to this.
regardless of the alleged brand or seller, they are all identical, however i recommend the seller from the link provided because they sent my LED strips and driver in a PVC tube, which guarantees its safety in transit, the LEDs i bought off an ebay seller at half price the price and no “e-packet” service (e-packet is like priority), came in a flimsy box and both were snapped in half, it was a miracle they only broke once, fortunately i was able to solder them back together for testing, i only needed to test out how hard i can run them anyway, so they served their purpose, though i did want some backup LEDs for the long run test when i switch out the driver for 2 constant current drivers.
Now, ill just reiterate what ive said before, i recommend that you also buy 2 adjustable stepdown converters (like from this post) , and a roll of thermal adhesive tape ( such as from this post ), and drive your LED strips at 500ma each, for a safe high brightness, or 700-800ma if you want to push it.
As i said in this post, the LED driver will output under 500ma (assuming based on the current draw, not actual output measurements, but it seems to be linear), regardless of how many LED strips are plugged in. Plug in 2, both get about <250ma, remove one, the remaining one gets double the power, i.e, the full output <500ma. They are under-powered so it still works in monitors that only use 1 LED strip, yet safely can drive 2 strips even if 1 fails or is removed, since its only 1 driver, not 2 in 1.
Let me also be VERY CLEAR, DO NOT RUN THE LED DRIVER FROM THE KIT OFF 24V, IT WILL BURN OUT.
I suspect it is a linear regulator, rather than a converter, much as it might look like one. This means its basically a resistor, it converts any excess voltage above 9-10v into heat, and at 500ma, this means you have 6W of excess heat with no ability to dissipate it, when running off 24V. When you buy a LED kit for use in the wacom, also buy a stepdown converter like the one linked above, the XL4015 costs about $2 or less depending on where you get it, and its more than capable of handling the job. It is capable of safely driving the LEDs on its own, however its better you drive them individually (so with 2 of them, 1 per LED strip) as you can only set the output voltage, not current. Other converters exist though with current control, a quick ebay search tells me a “LM2596” based converter exists with current control, for about $2-3ea, but really any will do as long as its a stepdown converter and has 2 or more trim potentiometers on there, if theres only 1, then it probably only controls the voltage.
Another option would be to just get some cheap 10W LED constant current drivers, 900ma seems to be the default intensity, if they are true to their description and can handle up to 24-30v, then you might be able to change a resistor on them to drop their control voltage from 900ma to 500, 700, or 800ma, whichever you want, for me its simple but, for you it might be a little more involved than youd like.
Also on ebay there seems to be a “3W DC-DC 700mA LED dimming controller” which has PWM support, but i have yet to test it and dont know if its limited to 3W output, at 700mA it seems unlikely. These cost about $4ea but could be direct replacements for the kit driver.
All of this may just be going overboard just a little though, you can just as easily get some cheap stepdown converters (but must be stepdown to properly be able to drop 24v to 9v), and use them to run the LED strips, no soldering, no fiddling, easy done. Its what im doing if the 10W 900ma drivers dont pan out.
Aside from the converters, the only other thing you will need, which you need either way, is a multimeter. you’ll have wire available from the cable that went to the inverter, it should have 2 sets of 24v positive and negative/ground wires there, cut or properly extract the rest, stick the two sets into the two converters, remove the plugs off the LED strip wires or cut and strip the wires, stick into the output of the converters, and your done. No soldering required, but you will need to test the output current with the multimeter to make sure its somewhere under 800ma, again, 500ma is most likely the safest, but 700ma is probably the rated maximum. If at 500ma i feel that it could still be brighter, i will try 700ma, but otherwise, when i eventually do this too, and i will provide more documentation as i have to open the monitor again to apply the adhesive, might even video it, i will be closing it up set to 500ma. its slightly over double what i have right now so, im pretty sure ill be happy with it.
So, to finalize, depending on how complex your prepared to go for replacing the CCFLs with LEDs, you will need the following:
Included in kit
- 2x LED strips
- plug wires
- driver (overheats on 24v)
Required;
- volt + current reading multimeter
- 1x 24v capable stepdown converter capable of handling 2A or more out (XL4015 recommended).
- 1.5M+ 6-8mm roll of thermal adhesive tape
- screwdriver for converter terminals
- tool for wire stripping (lighter or pliers, or something sharp)
- proper double sided tape or something to go under the converter so it doesnt short on the backplate, it MAY be able to be screwed onto the old inverter mounts, not 100% sure though. if you see another mounting option, go for it, so long as its secure.
Optional;
- Additional 1x stepdown converter, same model already bought (recommended XL4015)
- 2x constant current LED drivers with an output setting of 500-800ma and with an output voltage range that contains 9-9.9v.
- soldering iron, flux and solder ^ constant current drivers usually need to be soldered on.
- A second LED driver like from the kit, these are uncommon but do exist on ebay for about $1-5, heres one i saw earlier for $1.95
- a resistor, 10kohm or higher should do, this is to simulate the power-in signal the kit driver needs if you arent using the old outputs and control signals, connect between positive in and i think the 3rd pin from the right, the 4th should be PWM in, you can test by using your hand to conduct the power, it will turn in with ANY kind of input, it wont mess up the pwm in if you use the resistor or hand to test, unless the resistor is too low in value.
- heatshrink tubing if you have to combine wires
- dielectric grease , for the converter terminals if you stick bare wire into them, it would be bad if they oxidized and got hot. I recommend soldering them and/or keeping the original terminals intact from the provided wire.
Sorry for the late reply – I didn’t want to have just “yep, that’s what I meant” to add.
But of course, that is what I meant.
It took longer than I had expected to come up with a satisfactory solution for storing the converters, cables, plug to the power brick etc. but now it is done, tablet set up, driver installed etc. and: The tablet is in full working order, and all express keys as well as the three touch keys on the top are working.
Right now only Photoshop is not measuring pen pressure, but I guess that is a driver issue.
All in all – full repair, it is working. Thank you again.
First thing: It is working, and it is bright enough! On a day with full sunshine coming in it may be a close thing, but right now I’d say, with the current setup is it perfectly workable.
The converters feed the LED strips with about 600mA and around 9,4-9,5V. I left them running for about half an hour and the inner metal case wasn’t even warm to the touch, so I guess the aluminum-rails the LEDs are taped to do a good job of dissipating the heat.
Still heat is one of two remaining issues. I’d prefer to switch the two small fans at the top for bigger/slower ones to reduce noise and still have some reserves. There the construction is a bit irritating: I guess the system is that cool air comes in through the bottom vents (cooling the folded metal strip on the way) then is being pulled in by the fans (cooling the heatpipe at the top) and pushed out of the metal case.
Replacing the fans would mean to cut two really big holes in the (outer)metal case, and then it would still minimize airflow at the bottom part, so a rather imperfect solution.
The other issue is that the buttons are not working right now. While for the express-keys I guess it might be because right now there is no driver installed, the three buttons on the front/top should work. I am not sure if that is because a) I damaged the thin foil cable connecting them to the top pcb without noticing(the top/backside row of keys IS working), b) they are inactive because there is no signal from the inverter and they do need it for some reason or c) they, too, do need the wacom drivers. I will screw it all together, install proper drivers and check again.
If it is c), which I hope, I will find a box to put the stepdown converters in and attach them to the outside if the plastic case and call it done for now.
Maybe when letting the idea simmer for some time, a solution for more silent cooling will come to mind.
the i, keyboard and spanner touch buttons?
mine dont work either, could be a driver issue since they dont do anything on the monitor, they just trigger specific menus, and ive messed a lot around with drivers and stuff. could also be its just a very sensitive switch that isnt connected properly, or it got messed up by the decaying backlight. Fortunately though all those functions can be remapped to the express keys, so you havent especially lost anything. From what i recall those buttons used a very small fine ribbon cable, it would be easy to plug it in incorrectly so that it would be plugged in while not actually electrically connected. Still, you wont know for sure until you add drivers. In my case i just know i never cared much for them so i didnt really handle them gently, i may not have even plugged them in at all, i often pressed them accidentally, being touch sensors and all it only took the smallest thing
Thank you for your reply! I got impatient and already ordered all parts, installed them, and on the risk of frying something powered them up – and it is lighting up. So success! Now I’ll try to finetune stuff, as I’d like it to be a bit brighter (or if possible, a good deal brighter). As I started out with 8,9V to be on the safe side, I’ll dial this up now a bit higher and try to measure the mA, aiming for 600-700 you mentioned. (Also I see light coming out of the enclose through some gaps, so maybe I’ll open it up again and try to seal those areas with something light/reflective.)
A little tip is on the way(paypal) – thanks and merry Christmas!
thanks a bunch, its much appreciated.
Which areas do you see light comming out btw? if its the back, i think thats because youve removed the tape normally there, it makes sense that a bit of light would be escaping, but, any light you can save would probably help out in the larger scheme of things. if you can maybe try repurposing the reflector, remember, the LCD diffuses so ideally the LEDs should be focused pretty narrow.
It is indeed coming out of the back. While exchanging the CCFLs with the LEDs, I also removed the aluminum-“bracket”(?)/reflector the CCFLs sat in and taped the LEDs directly to the bigger aluminum rail for better heat transfer. Now I am thinking of trying and bringing it in again, to maybe get a more focused light.
There is another thing that I am wondering about – my multimeter, when put inline with the LED strip, shows only about 300mA at 9,0 / 9,1V – is that realistic in any way? (electronics noob again).
yes, the current increases exponentially with voltage once in range, if you turn it up to about 9.5-9.6V, you should have double if not more. LEDs should be driven according to current, so, make sure they are getting about 600-700ma. the optimal current should be reached around 9.8v, so, your far too low, very small differences in voltage are quite significant when it comes to LEDs. Anyway, before you move it around try running it on 600ma and see if its bright enough, if not, go to 700ma (per strip).
Btw, if your reading 300ma, is this with the driver the LED strips come with?
I am using the XL4015, one for each LED-strip.
Thank you again for pointing me in the right direction! I turned it up to 9,2V and now it is already at 440mA so I can see that double current will not nearly be double voltage. It is quite slow with only one multimeter, as I have to switch sockets/setting each time I check the other value, but I am getting there 🙂
yep, thats the way to go.
I hope that this is the right place to comment/ask:
I didn’t really pay attention, so I thought the plug from the led kit would directly fit into one of the sockets on the 24HDs circuit boards, possibly the one I just disconnected the inverter from. No such luck. From your photos it seems you “spliced” the cables going to the stepdown converter into sockets already in use?
Since I am a total noob in electronics, I don’t dare to try such a thing. Now my next thought was to solder the x/- wires to the stepdown converters (one for each LED-strip), and then using an adapter such as this one (https://www.amazon.de/DELOCK-Adapter-Terminalblock-5mm-Buchse/dp/B00E8CURKO/ref=pd_sim_23_4?_encoding=UTF8&refRID=XEXPEQQ9WRDEV2F594T5&th=1) connect them to a simple DC-power supply. Now I have no idea how to gauge the right specs, but I guess this one would be okay? (https://www.amazon.de/Salcar-Transformator-TFT-LCD-Monitor-LCD-Bildschirm-Überwachungskamera/dp/B01A6LQMWW/ref=sr_1_3?ie=UTF8&qid=1512405728&sr=8-3&keywords=24v+netzteil) 24V/3A or 24V/72W seems okay, or too much/less?
Also, to adjust the correct voltage at the converters (again, total noob) I connect them to the power source, put the pins from the multimeter to the out +/- points and turn the screw until the multimeter says 9V? Or do I have to do this in line with a consuming item?
Thank you for any tips.
the safe and simple route is adjust the voltage until it is 9v yes, if possible though you should watch the current, and get it to about 600-700ma, which will be attained somewhere between 9 and 10v, it varies from strip to strip.
That PSU will do the trick. as for the plug, if you feel uncomfortable cutting wires you can just stick some jumper cables into there and adapt with them.
Definitely having the same problem with the backlight not working for more than a second at startup so I need to fix this. I would just buy a clone for the same price of the repair at WACOM.
Joe I have a question. If I go the route of replacing the CCFL and the capacitors where you able to find the CCFL online that works in the 24″ Cintiq? Someone online mentioned the repair shop could not find one. I believe you said you ordered them and tried them out in your testing.
Second. In your final result using the LED strips -to be clear. You said this in an early post. “So replacing them with fewer LED strips is a very simple and viable option.
Simply put the tubes are replaceable for like $5 ea and the inverter is basically plugnplay, replacing it with LED to still work with the monitor controls would require very little effort. ”
Are you saying that you could buy new CCFL tubes for 5$ and a new inverter to plug and play for cheap? Did you find these online somewhere?
Or are you saying that making this an LED back light would just be 5$ with the controller?
thanks to let me know.
I like the idea of the LED back light and could live with off color if I must, but I’m not sure if I can convince a repair shop to make that change. A dimmer light than the original CCFL doesn’t sound great but may be necessary if I can’t buy the CCFL. I will keep checking in to see how your work progresses. It’s interesting for sure.
very detailed and interesting information Joe. thanks for such a thorough and detailed report. It’s an interesting idea to switch out to LED strips. You should be running a shop to just do this repair. There would be a lot of people asking for this repair instead of sending the tablet to Wacom.
Do you find that the tablet is now cooler on the glass surface? Did you notice any difference in the color represented on the monitor. Is the color still accurate?
Anyway just to have it brighter sounds worth it. thanks again
if the color is off, it was no better with the CCFLs, ive observed a few color mismatches between my monitors with the cintiq next to them.
Might also be that the cintiq is simply a better monitor and displaying more accurately, a specific characters palette didnt seem to match up the same on the cintiq as on my normal monitor.
Anyway, it does seem to be cooler yes, however CCFLs become inefficient as they die so my only reference is CCFL on the verge of death vs LED strip.
The monitor wont be brighter though, not with the strips ive recommended, im still searching for alternatives. It can at best be equal to moderate output from the CCFLs, but it will never be able to beat them on performance, not with these LEDs. Im actually considering building 2 high power strips myself, its not exactly hard and the monitor provides heaps more room than neccesary, the replacement kit LEDs are small/light duty lights, but its all thats available and when tweaked can perform moderately. it recently occured to me the total output of the strips is under 10W each, made up of some 30-40 LEDs, i often play around with LEDs i bought a while back which output 3W each and could easily be built into a strip. Finding less powerful more compact LEDs probably wouldnt be too difficult.
My situation/ standards are a tad different though because my monitor experiences very inconvenient glare during the day from the sun.
most people will be fine with the modified kit LEDs
If the backlight doesnt have any problems, dont touch it.
im thinking of making special LED strips just for the monitor, using different LEDs, i believe the ones currently inside are something like 2530’s (it reffers to their dimensions), but i can go all the way to 5050s or larger (which i calculated will allow a maximum of something like 40W per strip), im still working out though how to get aluminium or other PCB strip material at low cost, my current guess is that i need to get it in segments. this would make it unfortunately a little more involved to install, soldering 10cm strips or so, together in series, but, logistically that would make them incredibly cheap to post as well as safe without the use of mailing tubes. Im learning to make gerber files for this exact purpose.
I know this web page offers quality dependent content and other stuff, is there any other web page which presents these kinds of information in quality?
not that i know of sorry. Looks like im the only person who has documented the repair process