This is a Design I made in 2022 bcs then I finally had the chance to acquire a THS720A for a reasonable Price but the Backlight CCFL was dead ! I reverse Engineered the existing CCFL just to see what is done and Designed a 1:1 Drop-in Replacement Converter for the LED Strip Backlight. I used a 12V 3mm thin LED Strip cut down to Length, this way the White CCFL Plastic Holder can be used again.

The Led Strip I used is the : https://www.aliexpress.com/item/4000912596869.html another option is this one : https://www.aliexpress.com/item/1005003193200776.html I bought it but I didn’t used it because the first one is very good. In case the Links doesn't work anymore Search"3mm PCB 5M 2520 SMD 168leds/m 12V" or "2.7mm Super Slim COB LED Strip Light for Car Room Decoration 3V/12V 480LED/m" on AliExpress.

I used fixed Voltage Steps of 12,13,13,15V using solder Jumpers instead of a trimmer Pot, if other Voltages needed I included the resistor calculation in the Schematic. R1 in the Formula is the 160K Divider Upper Resistor and R2 is the Divider Lower Resistor. The LED Strip can be Driven up to 15V with nothing getting really warm, at 12V Output the LED Controller draws ca. 120mA with 5V Input and ca. 40mA with 12V Input.

Please use only the X1 (SMD) or X2(THT) Connector, not Both !

More Info's & Pictures see my Post on the EEVBLOG: https://www.eevblog.com/forum/testgear/tektronix-ths7xxx-scope-ccfl-controller-drop-in-replacement-for-led-conversion/

Please see my YouTube video on this design at https://www.youtube.com/@KonstantinGrigoriadis