Replacing LCD with VFD, VFD not doing anything but whining. M68 vs I80 modes? - Page 1
Forum section: electronics / beginners

author: Mp3
author_rank: Frequent Contributor
timestamp: March 16, 2018, 09:50:08 pm
content: I remembered I had an unused 40x2 lcd lying around. I soldered up the proper connections to it and it works perfectly! So now i am trying to figure out why the VFD doesn't work. Would plugging it in backwards kill it? the pinout has pins 1 and 2 having VCC and ground respectively, whereas 13 and 14 are data address lines. I know the LCDs can tolerate being plugged in backwards but i don't know if the VFD can. I bought it used and the data sheet doesn't seem to have a self test mode specified.The data sheet says it ships in Motorola mode. How can i tell if it needs to be switched to Intel mode? I have an oscilloscope.Original Posti have been struggling with this for the last 4 or 5 hours and it is driving me mad.i got a replacement 40x2 lcd for my Akai S900 sampler with a completely dead EL backlight. All the guides online show the chinese made LCDs that have 16 pins on the side, and i got one that has only 14 pins on the side like the stock Akai one.However it doesn't have space for the two backlight power/ground lines, so i assumed it took whatever power it needs from the 14 pin connector. Except nothing happens when i power on the sampler.Is there any chance i need to re route the backlight power to the display regardless? It ships in Motorola mode and can be switched with jumpers to Intel mode. Is that what i need to do? The original display works fine if i plug it back in with the inverter, so i'm not sure what i need to do from here! I could get one of the china LCD's but i paid $25 for this VFD and gosh darn it I want to use this VFD! One thing that worries me if I plug the VFD it makes a loud whine, but if i flip the connector around it doesn't whine although the S900 doesn't boot up. So i have the original nearly unreadable display back in it... It still works fine with its stock display.I did not notice until after 1st time i plugged it in that where pin 1 is on the stock display, is where pin 14 is on the VFD, could this have fried it?It's a Futaba M402SD10FJ. I know the ones people usually use for drop in replacements are Noritake's. When i try to start up the S900 with this VFD, nothing shows on the display but there is a loud whine coming from the VFD making me worry it is deadAdditionally, it seems that there is no self test mode on this Futaba display i can findHere is the datasheet for my displayhttps://datasheet.ciiva.com/14089/dhfutaba-vfd-text-m-m4025d-en-14089327.pdfHere is the datasheet for the Noritake several people have used on different synths according to googlehttps://www.mikrocontroller.net/attachment/6360/CU40025SCPB-W6J_E02.pdfAnd here is the datasheet for the china LCD that is all over ebay and requires you to hook up the backlight power wires, but it's what most people use and is definitely plug and play.http://www.buydisplay.com/download/ic/SPLC780.pdfany help would be greatly appreciated!

author: Mp3
author_rank: Frequent Contributor
timestamp: March 18, 2018, 05:59:04 am
content: Rewrote OP...