TDS3000 series CCFL upgrade to LED - Page 1
Forum section: electronics / repair

author: Tracker
author_rank: Regular Contributor
timestamp: December 04, 2021, 04:47:28 pm
content: Just sharing this.Used a standard CCFM conversion kit from Banggood.Worked out very well.https://www.banggood.com/490mm-LED-Backlight-Strip-Light-Kit-DC-10-30V-22-Inch-CCFL-LCD-Screen-to-LED-Monitor-Module-p-1832364.html?cur_warehouse=CN&rmmds=searchNote: when cutting the strips down to size, be sure to reduce the current proportionately by using a 1k pot on the dimmer line.The LED's are arranged in groups of 3 series , each group is in parallel.You will need to pull the 'enable line' high to activate the converter.The Tek 3000 series CCFL is powered from +5V which can't be used, so you you will need to locate +14v on the main control board, pins 5 & 6 if recall correctly (pin 1 is ground).End result is a massive improvement over the old CCFL.But you loose the brightness control from the instrument, not a big deal to be honest.

author: Teichhermelin
author_rank: Regular Contributor
timestamp: December 04, 2021, 07:52:47 pm
content: Very nice!

author: james_s
author_rank: Super Contributor
timestamp: December 05, 2021, 04:34:53 am
content: Loosing the brightness control would bother me just on principal. I've never looked at the signal that controls that, is it just PWM? It may just be a matter of hooking up a wire to make that work. Certainly there are lots of LED drivers with PWM brightness controls, I've used the PT4115 IC and it has both PWM and analog support.

author: sean0118
author_rank: Frequent Contributor
timestamp: December 05, 2021, 08:44:14 am
content: I haven't checked but from memory it should be possible to add brightness control:www.reflektor.kz/articles.php?article_id=45

author: Tracker
author_rank: Regular Contributor
timestamp: December 05, 2021, 07:22:10 pm
content: yep it should be.The Banggood controller board can be adjusted with a DC level between 0 and 3 volts.So even if the Scope generated PWM, a PWM converter board or even filter could be used.Buy honestly I never had the need to adjust the brightness, but I guess that it would be handy if you used the scope in portable mode.

author: james_s
author_rank: Super Contributor
timestamp: December 05, 2021, 07:40:47 pm
content: I don't adjust it very often but I do occasionally dim it when I'm using it in subdued lighting. The dimming is not as useful as it could be though, there are only 2 or 3 settings.

author: sicco
author_rank: Regular Contributor
timestamp: December 26, 2021, 04:01:35 pm
content: I ordered the same Banggood LED strips with chopper board.What I got was red wire = GND, black wire = V+…. I was lucky, there was no Bang. But this is not Good I’d say. Anyway, it survived, tied one of the two yellow wires (enable) to V+.I did end up using double sided tape on the back of the LED strips. Without tape I could not keep the strips pointing the right way.I left out intensity control. I always run off mains power, so no need to sacrifice backlight intensity for battery life.The dial on the front panel BTW does not influence screen backlight intensity for the old CCFL lamps anyway. So you’re not losing anything by not having backlight intensity ‘replicated’: the dial just mimics analog scope intensity in software by turning on/off more pixels.

author: james_s
author_rank: Super Contributor
timestamp: December 26, 2021, 10:57:21 pm
content: That's true about the dial, but there is a menu setting that offers 2 or 3 different backlight intensity settings. I agree that there is rarely a need to turn it down though.

author: sicco
author_rank: Regular Contributor
timestamp: December 27, 2021, 02:10:16 pm
content: Yes, I found the Backlight Intensity dial eventually under the Display button, H,M,L.As the LED strips are 3 times longer as needed, and I had another TDS3012, I decided to give that a go also. My learnings today: best to get rid of the chopper board and just power the LED strips from DC with a small current limiter/controlling resistor. I picked the +5 and -15V rails to get 20 VDC, then the two strips in series and 150 ohms as current control, 25-30 mA is good enough for me already, but maybe go much higher if you want more light. The strips have every 3 white LEDs in series, so 3xV_LED, and that's 7 to 9 V ish)).I think it's better anyway to not have a LED chopper circuit inside the scope, I have the impression that in the first one I did, with the PWM chopper, I now see more noise/ripple on my channels as before...Plus: do re-use the metal frame that had the old CCFL glass tubes, then no need for double sided tape for holding the strips in position anymorePlus: leave out the entire high voltage chopper board. The scope works fine (for me) without it.

author: JJ2PNX
author_rank: Newbie
timestamp: January 02, 2022, 09:17:15 am
content: Hi,I built dedicated LED driver board for this scope.https://www-momose-com.translate.goog/hirofumi/elec/BacklightLED/index.html?_x_tr_sch=http&_x_tr_sl=ja&_x_tr_tl=en&_x_tr_hl=ja(google translated, originally in Japanese)Dim and backlight-off works as same as CFL board.This CFL inverter dimmer control interface is a bit strange voltage level.

author: jgorsk
author_rank: Regular Contributor
timestamp: January 21, 2022, 11:28:53 am
content: Here is another LED driver for the TDS300 backlight.It's based on the LT3922. Maximum LED current is controlledwith R1 value. Imax = 100mV / R1

author: wraper
author_rank: Unknown
timestamp: January 21, 2022, 11:32:40 am
content: Quote from: Tracker on December 04, 2021, 04:47:28 pmAnd completely messed up color reproduction. Most likely LEDs are not suited for display backlight and use simple yellow phosphor over blue LED die.

author: jgorsk
author_rank: Regular Contributor
timestamp: January 21, 2022, 11:55:20 am
content: With natural colour LEDs, the colour reproduction isn't great. That's true.I will be trying custom LED boards with LEDs that have similar colour temperatureto CCFL light. I will try Lumileds L130-3090001400001My CCFL lamps were worn, changing them with LED backlight seemed likea quick and easy solution but I ended up designing my own driver boardand LED backlight boards too.

author: james_s
author_rank: Super Contributor
timestamp: February 14, 2022, 10:27:08 pm
content: Quote from: JJ2PNX on January 02, 2022, 09:17:15 amVery nicely done!

author: Abel
author_rank: Newbie
timestamp: April 21, 2022, 11:02:04 pm
content: From time to time some subjects get revived. If there is any interest:a linear solution (see attach) with dim control for TDS30xx(X).Maybe a little more information will help upfront: the dim functionality uses the original control signal from scope (roughly 1.55 to 2 V) and the +5 V supply via the 6 pins connector that the CCFL controller/driver used. However, additional voltages are needed (-5V and +15V), both available from the scope PS (detailed information w/pictures in file).AB

author: jgorsk
author_rank: Regular Contributor
timestamp: January 09, 2023, 05:20:00 pm
content: RGB LED backlight produces a lot better colours. I tried the ASMB-UTF2-0E20B LEDs. 27 of them per side.18 or 21 LEDs per side would probably work as well. I can get colours very similar to the original or even better.

author: Wahyueko
author_rank: Contributor
timestamp: January 09, 2023, 11:14:39 pm
content: Nice sharing , i want to try with my tds3054b

author: Miti
author_rank: Super Contributor
timestamp: February 13, 2025, 10:20:32 pm
content: I've contacted the forum member JJ2PNX and he was kind enough to send me the design files for his board.I've ordered a set together with another project and I assembled and tested two boards. They work perfect, Japanese attention to details !Thank you, JJ2PNX !Cheers,Miti

author: daveyk
author_rank: Frequent Contributor
timestamp: June 24, 2025, 08:19:43 pm
content: I need a few of these boards. Where can I get them? Will PCBWay make them?

author: daveyk
author_rank: Frequent Contributor
timestamp: July 03, 2025, 03:59:31 pm
content: Quote from: JJ2PNX on January 02, 2022, 09:17:15 amPerchance would you be willing to supply the Gerbers and BOM? I need to have several of these boards made.Thank you, kindly.

author: JJ2PNX
author_rank: Newbie
timestamp: July 12, 2025, 02:17:08 am
content: Design files attached. Feel free to use it.

author: daveyk
author_rank: Frequent Contributor
timestamp: July 12, 2025, 04:27:23 pm
content: Quote from: JJ2PNX on July 12, 2025, 02:17:08 amThank you, very much. I had a hard time finding some of the parts. I do have a bunch on order, and PCB's. I will need to do some experimenting.Could not find the Input connector, nor the LED strips. They still have them at the company in the BOM link, but they do not like the US Zip code and could not make it to checkout.Dave

author: JJ2PNX
author_rank: Newbie
timestamp: July 13, 2025, 12:50:47 am
content: Input connector IL-Z-6PL-SMTYE is now EOS. Only way to get is from market stock.I bought them from ali-express several years ago. But I cant find now at.

author: Cyclotron
author_rank: Unknown
timestamp: July 14, 2025, 08:47:13 pm
content: Quote from: JJ2PNX on July 13, 2025, 12:50:47 am@JJ2PNXThank you very much for the information on your boards. I am also pursuing building this to use.As @daveyk said, I've had trouble locating some of the parts available for order from reputable suppliers in the US.I'm still looking for a source for the XL6001 LED driver or a substitute as well as connector you mentioned above and the LED strip you used.Given that I'll be swapping these in for the CCFL controllers, I can likely scavenge the connector from that board or build new cables using available connectors.I suspect that I can buy some LED strips and play around with various ones to find a set that works.I'm currently most worried about the LED driver as the board design specifies this pin out.Thank you again for giving this to the community.

author: JJ2PNX
author_rank: Newbie
timestamp: July 17, 2025, 01:57:04 pm
content: Molex 53261 may be a similar fit for input connector.

author: Cyclotron
author_rank: Unknown
timestamp: July 17, 2025, 03:30:29 pm
content: Quote from: JJ2PNX on July 17, 2025, 01:57:04 pmThank you!!I will order 1 or 2 in my next order and test. I have a unit that I am going to start working on soon so I'll have the chance to try it out.I still need to locate and order some XL6001 LED drivers and LED sticks of the right length.

author: Cyclotron
author_rank: Unknown
timestamp: July 17, 2025, 11:15:58 pm
content: So, I've got a few XL6001E1 LED drivers on order from what looks to be a reputable ebay supplier from China.I've found this LED strip:https://www.plazmo.com/collections/led-strips/products/universal-led-backlight-kit-for-7-to-15-lcd-panels-for-led-replacement-and-ccfl-conversionThese are cut to length and have the JES connectors. They are rather expensive.These are cheaper so I ordered a pair to test.https://www.aliexpress.us/item/3256806567471636.html?spm=a2g0o.order_list.order_list_main.5.21ef1802P97XvX&gatewayAdapt=glo2usa

author: JJ2PNX
author_rank: Newbie
timestamp: July 19, 2025, 11:40:36 pm
content: I use following led strip.https://www.aitendo.com/product/5369158 mm is bet fit, no modification needed.If you want, I can buy it and send to you.

author: Cyclotron
author_rank: Unknown
timestamp: July 20, 2025, 05:55:17 pm
content: Quote from: JJ2PNX on July 19, 2025, 11:40:36 pmThank you!!! I would love to use the same ones you've used in your design. I'll send you a PM to discuss logistics.

author: Cyclotron
author_rank: Unknown
timestamp: July 26, 2025, 06:41:17 pm
content: Quote from: JJ2PNX on July 17, 2025, 01:57:04 pm@JJ2PNXI believe you've nailed an option for this connector that's no longer available. I ordered some Molex 53261 units and they arrived.In the attached photos you can see the results of fitting the original wire with connector to the molex socket. The only variance is the small plastic nib that I assume the original used for better retention.I think there's a few solutions.Just use the Molex socket without change, there's only a small amount of deflection but I have not tried this when soldered to a board.Modify the cable connector using a sharp instrument to shave the nib offModify the molex connector by either slicing the plastic out or punching a small hole for the nib to locate into.The last option would make the new LED driver boards more compatible with the systems these would go into so if someone were building some for sale or sharing that might be the best option. I have a couple spare so I am going to do some trials with modifying the molex socket to see how easy a solution might be.Thank you so much for your work!

author: Cyclotron
author_rank: Unknown
timestamp: August 05, 2025, 12:42:01 am
content: So close.I thought I had everything to build a test unit but sadly, I didn't check twice on my packages for the OpAmp. So, I'll order the proper ones and should be able to test this coming weekend.Attached is a photo of a nearly completed driver board.@JJ2PNXThanks for the design, documentation, and all your help.

author: JJ2PNX
author_rank: Newbie
timestamp: August 06, 2025, 01:36:56 pm
content: Hello,Please select so-called, single supply op-amps.Generic 15V dual supply op-amps in 5V rail cause narrow input range and insufficient.

author: Cyclotron
author_rank: Unknown
timestamp: August 06, 2025, 01:55:25 pm
content: Quote from: JJ2PNX on August 06, 2025, 01:36:56 pmI've ordered theses from Mouser:https://www.mouser.com/ProductDetail/513-NJM2746M-TE1NJM2746M-TE1I couldn't find any SOC8 in stock but these are DMP8 and I think they will fit.

author: Cyclotron
author_rank: Unknown
timestamp: August 10, 2025, 09:21:09 pm
content: Here's the results.I used JJ2PNX's designs and only had to make very small adjustments to get a working solution given availability of some of the parts.I'm stoked at the results. The display is so bright and uniform. I love it. It really is transformative. I can't tell you what one of these looks like with new CCFL but here are 3 photos I've taken to show the original CCFL in this unit vs. the LED on high and then low. I have two more to do so I will take photos on all settings with CCFL then all settings with LED.@JJ2PNX, I can't thank you enough. This is a fantastic modification and the board works perfectly for dimming the backlights.