3.5 LCD (fb_ili9486 ) - still not working after days of trying

I have been trying for about 3 day’s, to get this display working.
The display is probably a clone of waveshare.
I also searched this forum, but still without succes. How somebody can help me!

Configuration:
DietPi v6.31.2 : 20:19 - Wed 08/05/2020

  • Device model : RPi 4 Model B (armv7l)
  • HDMII monitor attached
  • 3.5 LCD attached via GPIO

Problem

  • screen stays white

/boot/config.txt contains:

hdmi_force_hotplug=1
dtparam=spi=on
dtparam=audio=on
dtoverlay=waveshare35a

/boot/overlays contains among others:
-rwxr-xr-x 1 root root 2682 Aug 5 13:50 /boot/overlays/waveshare35a.dtbo
-rwxr-xr-x 1 root root 2682 Aug 5 13:50 /boot/overlays/waveshare35a-overlay.dtb

output of root@DietPi:~# dmesg|grep “fb|graphics|display|touch|ads”

[    0.000000] Kernel command line: coherent_pool=1M 8250.nr_uarts=0 snd_bcm2835.enable_compat_alsa=0 snd_bcm2835.enable_hdmi=1 snd_bcm2835.enable_headphones=1 bcm2708_fb.fbwidth=1280 bcm2708_fb.fbheight=768 bcm2708_fb.fbswap=1 smsc95xx.macaddr=DC:A6:32:24:95:EE vc_mem.mem_base=0x3ec00000 vc_mem.mem_size=0x40000000  dwc_otg.lpm_enable=0 console=ttyS0,115200 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwait fbcon=map:10 fbcon=font:ProFont6x11 logo.nologo
[    0.972901] pci_bus 0000:00: root bus resource [mem 0x600000000-0x603ffffff] (bus address [0xf8000000-0xfbffffff])
[    0.983110] bcm2708_fb soc:fb: FB found 1 display(s)
[    1.016517] bcm2708_fb soc:fb: Registered framebuffer for display 0, size 1280x768
[    5.494259] ads7846 spi0.1: spi0.1 supply vcc not found, using dummy regulator
[    5.494871] ads7846 spi0.1: touchscreen, irq 56
[    5.513460] fbtft: module is from the staging directory, the quality is unknown, you have been warned.
[    5.517355] fb_ili9486: module is from the staging directory, the quality is unknown, you have been warned.
[    5.518090] fbtft_of_value: regwidth = 16
[    5.518106] fbtft_of_value: buswidth = 8
[    5.518126] fbtft_of_value: debug = 0
[    5.518141] fbtft_of_value: rotate = 90
[    5.518158] fbtft_of_value: fps = 30
[    5.518173] fbtft_of_value: txbuflen = 32768
[    6.395370] graphics fb1: fb_ili9486 frame buffer, 480x320, 300 KiB video memory, 32 KiB buffer memory, fps=33, spi0.0 at 15 MHz

Any help is appreciated!!