Replacement LCD -> blown F2 fuse
Hi - having scavenged my original Prusa LCD for the MK3 upgrade, I'm trying to put my MK2S back into service with replacement parts. I bought a generic 2004lcd and something odd happened. The display was fine and the reset button worked but the rotary encoder wasn't acting right at all. Twisting right from the info screen actually brought up the menu, twisting left blew the F2 fuse. I don't really know how to debug a rotary encoder with a multimeter but continuity checks didn't find any shorts in the ribbon cables and point to point tests of the board seemed to show everything ok. Has anyone seen this before? Does it sound like just a bad encoder or should I be looking elsewhere?
Thanks,
Henry
Re: Replacement LCD -> blown F2 fuse
I would check is your LCD 2004 or 2004A and are the connectors oriented differently from Prusa LCD?
Bill
Tagaytay City, Philippines
Founder member of Philippines Prusa Printer Owners FB Group
Sponsor Pillars of God Academy in Bacoor
Re: Replacement LCD -> blown F2 fuse
2004A, does that make a difference? The connectors are indeed oriented differently but I flipped them around on the motherboard side to compensate. It's fairly easy to tell when they're upside down. EXT1 sends VCC straight to the buzzer when you do that so if the display doesn't light up but the buzzer is on continuously it's upside down.
Henry
Re: Replacement LCD -> blown F2 fuse
Sorry it's not clear what you are calling the motherboard.
The Rambo end should not be flipped, the LCD end should. Is that how you have it?
Bill
Tagaytay City, Philippines
Founder member of Philippines Prusa Printer Owners FB Group
Sponsor Pillars of God Academy in Bacoor
Re: Replacement LCD -> blown F2 fuse
I don't remember which way I had it when the fuse blew. The first time I connected everything the display came on but displayed garbage for a few seconds before settling down to displaying everything correctly. I tried flipping the cables around in all orientations to see what other results I get but it seems like it's pretty easy to tell if EXP1 is upside down. If it is, the display won't come on and VCC goes straight to the speaker (which comes on continuously). So I chose the orientation that lights up the display and matched that orientation for EXP2.
When I pick up a new fuse I'll report back with the exact orientation.