RRD GLCD startup problems with new psu

Hi Folks,
I have a smoothieboard and RRD GLCD which were getting along fine until I switched to my new bigger PSU ( that can cope with my new 200W hotbed).

Now the LCD doesn't seem to be initialised properly, I get a couple of lines of random dots instead of text.

Every now and then if I power up then off then on again I get a proper display.

Switching back to my old PSU makes everything work again so I'm suspecting there is a problem with the rise time of the voltage being too slow and reset not happening smoothly.

Has anyone else had this problem and did they solve it?

cheers,
Robin.

On the Azteeg X5, several people have reported that powering a GLCD from the on-board 5V supply causes similar problems. Mine was a coin toss as to whether it would display the Smoothie banner or gibberish. Even if it did boot clean, it would change to gibberish after a few minutes. The recommended fix is to power the GLCD from an external 5V source. I got away with changing the board from internal 5V to use USB 5V and my display has worked non-stop for a few months.

In any case, I'm guessing that you are also experiencing weak 5V power to the GLCD, and tapping an alternative 5V power supply will fix it.

Now, I'm wondering if your theory of the 5V rise time being slow might be a factor in the Azteeg's issues with the GLCD, and if inserting a small delay in Smoothieware before initializing the GLCD on boot might resolve bot your and the Azteeg's problems?????

Well my 5V is coming from the same regulator in both cases, working with old 140W 12V PSU and not working with new 1100W(!) 24V PSU (it was a surplus bargain on ebay).
The regulator is a switcher rated at 1.5A and up to 30V Vin, so there shouldn't be a problem there really which was why I suspect timing.
'spose I should put my money where my mouth is and have a go at inserting a delay like you suggest

Cheers,
Robin.

Nope, delaying five seconds before the init made no difference. Hitting reset on the smoothieboard doesn't sort things out either.

How does the voltage on the 24V supply look when you power up the printer? Does that monster supply need a minimum current to help it keep the power regulated and clean? (Some of the ATX supplies need 0.1A.) How clean is the output?

I just went 24V myself two weeks ago. The 300mm diameter Onyx heatbed on my printer was taking 40+ minutes to reach 110C on 12V - even with an external SSR. Several people on the SeeMeCNC forum went with 24V Mean Well power supplies, and dialed back the voltage adjuster to 18-19V. The Onyx can now reach 110C in 6 minutes on the 19V that I'm feeding it, and the 12V/20A buck converter that I bought from Amazon put out a steady 12.0V for the electronics/steppers/hotend with the 19V input power. I haven't switched the Azteeg's 5V source back from USB to on-board power to see if the new power supply helped with the GLCD gibberish on boot, but otherwise I am kicking myself for not going 24V sooner.....