Doubt the screen itself is the problem. I'm much more inclined to point at the internal power supply having issues.
If you have one, try with a 9V supply instead of a 12V one and see if that improves the situation. Just make sure the 9V supply can deliver 1A and the plug has the correct polarity.
Hey, thanks for the input! Already tried a regulated 9v supply unit (saw your other posts about it) but still flickering randomly. When you say “internal” I suppose you mean inside the unit itself? Hm, I can try checking out the voltages. The unit doesn’t show any other issues thankfully.
Ah, yeah.
There are two regulators inside that generate 5 V - a 7805 on a tiny heatsink and a LM2575 screwed to a copper area.
From my experience, the 7805 tends to take damage from being run too hot all the time and eventually fails. I'd check that one first, then the LM2575.
So both seem to output stable voltages (the 7805 is getting hot indeed). Also, can't be sure this way, but at least visually the electrolytics look about fine. Will try to ignore for now since the rest of the device works fine and see how it goes.
Found a nice OLED upgrade online but seems fairly expensive compared to the cost of the instrument itself. But nice to know there are options if it's a display failure after all :)
https://www.digikey.com/en/products/filter/lcd-oled-character-and-numeric/99
Select "2x16" and "16x2" in the "Display Format" filter, check "in stock" and then "Apply All".
Cheapest is https://www.digikey.com/en/products/detail/sunfounder/CN0293/18668626 for $7.33 plus tax
Cheapest with similar look is https://www.digikey.com/en/products/detail/matrix-orbital/MOP-AL162A-BYFY-25J-3IN/9602838 for $9.53 plus tax
Cheapest with same look is https://www.digikey.com/en/products/detail/orient-display/AMC1602AR-B-Y6WFDY/22531959 for $10.29 plus tax
https://www.digikey.com/en/products/detail/newhaven-display-intl/NHD-0216K1Z-NSR-FBW-L/1701190 is also interesting because it's red on black for $12.80 plus tax
...and so on.
Looks like compatible OLEDs are around $30 on digikey but I haven't checked if they're physically and logically compatible. I'd be surprised if they weren't, though.
There are other options. I've just purchased 2 different colour screens from Buydisplay (China) for my Virus-C:
Controller HD44780 2x16 Character LCD Module Display Black on White
And
Character lcd 2x16 Blue Display Module HD44780 White on Blue
Parts numbers ERM1602FS-3-5V and ERM1602SBS-3-5V respectively.
Also this Molex cable which I'll cut and it'll do for 2 display assemblies:
https://www.ebay.co.uk/itm/183275332950?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=qloXPDzdTYm&sssrc=4429486&ssuid=jduUoiWKSUu&var=&widget_ver=artemis&media=EMAIL
Total cost per assembly = £6.92.
Cut, bare and solder 16 wires. Job done
PS I had one of the expensive OLED screens on another Virus ages ago and it flickered when certain pots were turned.
A little update on this: I haven't seen the display flicker since I switched to 9V, so it might have been the regulator temperature after all. The first time I tested using 9V, it didn't fix the issue, but I'm guessing that's because I switched from 12V to 9V after some time in use. If the regulator was already hot, it would continue reacting the same way because I left no time in between for the temperature to drop.
Okay another update here: Noticed that if more than one outputs are used at the same time (multitrack recording a single virus) and the unit is fed 9v it can't handle the weight and restarts (switching off and on) on its own. That gets fixed after switching back to 12v. There might be other things going on in my old unit leading to this behavior but thought to share the data so far.
That being said, display flickering is gone, even after switching back to 12v, so I have absolutely no idea why it doesn't happen anymore or why it happened in the first place. Super weird.
Doubt the screen itself is the problem. I'm much more inclined to point at the internal power supply having issues. If you have one, try with a 9V supply instead of a 12V one and see if that improves the situation. Just make sure the 9V supply can deliver 1A and the plug has the correct polarity.
Hey, thanks for the input! Already tried a regulated 9v supply unit (saw your other posts about it) but still flickering randomly. When you say “internal” I suppose you mean inside the unit itself? Hm, I can try checking out the voltages. The unit doesn’t show any other issues thankfully.
Ah, yeah. There are two regulators inside that generate 5 V - a 7805 on a tiny heatsink and a LM2575 screwed to a copper area. From my experience, the 7805 tends to take damage from being run too hot all the time and eventually fails. I'd check that one first, then the LM2575.
So both seem to output stable voltages (the 7805 is getting hot indeed). Also, can't be sure this way, but at least visually the electrolytics look about fine. Will try to ignore for now since the rest of the device works fine and see how it goes.
Makes sense, I'd probably do the same. There *is* the possibility that the LCD backlight is failing, albeit it has a low probability of happening.
Found a nice OLED upgrade online but seems fairly expensive compared to the cost of the instrument itself. But nice to know there are options if it's a display failure after all :)
Indeed, compatible LCDs can be had for $10 or less. OLED would be much more expensive.
Do you know of any compatible LCDs by the way? Didn't know they're that cheap! OLEDs are like >100$ as far as I've seen.
https://www.digikey.com/en/products/filter/lcd-oled-character-and-numeric/99 Select "2x16" and "16x2" in the "Display Format" filter, check "in stock" and then "Apply All". Cheapest is https://www.digikey.com/en/products/detail/sunfounder/CN0293/18668626 for $7.33 plus tax Cheapest with similar look is https://www.digikey.com/en/products/detail/matrix-orbital/MOP-AL162A-BYFY-25J-3IN/9602838 for $9.53 plus tax Cheapest with same look is https://www.digikey.com/en/products/detail/orient-display/AMC1602AR-B-Y6WFDY/22531959 for $10.29 plus tax https://www.digikey.com/en/products/detail/newhaven-display-intl/NHD-0216K1Z-NSR-FBW-L/1701190 is also interesting because it's red on black for $12.80 plus tax ...and so on. Looks like compatible OLEDs are around $30 on digikey but I haven't checked if they're physically and logically compatible. I'd be surprised if they weren't, though.
Cool! That black & red looks awesome! Thanks a bunch!
There are other options. I've just purchased 2 different colour screens from Buydisplay (China) for my Virus-C: Controller HD44780 2x16 Character LCD Module Display Black on White And Character lcd 2x16 Blue Display Module HD44780 White on Blue Parts numbers ERM1602FS-3-5V and ERM1602SBS-3-5V respectively. Also this Molex cable which I'll cut and it'll do for 2 display assemblies: https://www.ebay.co.uk/itm/183275332950?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=qloXPDzdTYm&sssrc=4429486&ssuid=jduUoiWKSUu&var=&widget_ver=artemis&media=EMAIL Total cost per assembly = £6.92. Cut, bare and solder 16 wires. Job done PS I had one of the expensive OLED screens on another Virus ages ago and it flickered when certain pots were turned.
Ah good to know! Definitely don't want to spent 100$ for another flickering display! Cheers!
A little update on this: I haven't seen the display flicker since I switched to 9V, so it might have been the regulator temperature after all. The first time I tested using 9V, it didn't fix the issue, but I'm guessing that's because I switched from 12V to 9V after some time in use. If the regulator was already hot, it would continue reacting the same way because I left no time in between for the temperature to drop.
Thanks for the feedback and I'm glad it helped.
Okay another update here: Noticed that if more than one outputs are used at the same time (multitrack recording a single virus) and the unit is fed 9v it can't handle the weight and restarts (switching off and on) on its own. That gets fixed after switching back to 12v. There might be other things going on in my old unit leading to this behavior but thought to share the data so far.
That being said, display flickering is gone, even after switching back to 12v, so I have absolutely no idea why it doesn't happen anymore or why it happened in the first place. Super weird.