VFD display problem

Testing/Troubleshooting
1

Hello!

I have a problem with my VFD display Futaba M202SD16AJ. 1.9d - O.K., 1.9g - blank display.

I use this schematic - http://ucapps.de/mbhp/mbhp_lcd_4bit_mios8.pdf, display work fine via mios 1_9d, (I use old pic 18F4685 from smash tv), after that I install the last firmware sid2, display still works fine, then I update mios to v1_9g, and after that i got a blank display after this update.

This some bug?

How I can fix it?

Maybe I can back to mios v1_9d?, but I cant find any old mios version.

Anybody can help me?

2

Going back to 1.9d shouldn’t be necessary. What do you get after the update (with only MIOS installed) - nothing, black bars, “Ready.”?

From the link I assume you wired the display in 4bit mode?

Did you upload the correct mios version (for pic 18F4685)?

Are you using the latest release of SIDv2? Older ones might initialize in 8bit mode by default (too lazy to check).

3

check the 4bits wiring

4

Have you checked the Pic-ID?

Mios can be set to use different display-drivers via this ID.

You can reset it to all zeros with the change_id app found here under troubleshooting.

5

Thanks for you attention and help! :slight_smile:

All operations I made in MIOS Studio 2.1

Update to new mios was be correct – for Pic 18F4685 via midi.

Once again, step by step:

  1. I connect my VFD display Futaba M202SD16AJ via 4bit ( http://ucapps.de/mbh…_4bit_mios8.pdf ) to Core with Pic 18F4685 with mios v1_9d. After power on display show me “READY.â€

  2. I load the last sid v2 firmware - V2.0_rc37, display show me how formatted my memory chips and after that I can see MidiBox Sid V2 interface on my display, I load patches and test the sound of my 6581.

  3. I update mios to v1_9g, and after that I got a blank display (I see nothing) after this update.

  4. I load again last sid v2 firmware - V2.0_rc37, display still blank (I see nothing), but my 6581 sound ok!

  5. Post this topic.

  6. Reset id to all zero via change_id app, load mios v1_9g, load last sid v2 firmware - V2.0_rc37, display still blank (I see nothing), but my 6581 sound ok!

  7. I double check connection via lcd_interconnection_test_v2.zip, and check again data shit for my display and found one error… Pin 3 must be not connected, but I connect them to the V0 Pin on Core.

  8. I load again last sid v2 firmware - V2.0_rc37, display still blank (I see nothing), but my 6581 sound ok!

  9. I check another LCD display, it works fine!!!

I kill my VFD via mios update, because I forgot disconnect Pin 3?

I can’t understand what’s going on. =(((

6

I kill my VFD via mios update, because I forgot disconnect Pin 3?

No. You killed your VFD by feeding a DC voltage into a data pin - which is a fairly common way of killing displays.

7

Ok, but how display works befor I udate mios to 1.9g? Pin 3 always be connect to V0, befor display dead.

[M202SD16AJ.pdf](< base_url >/applications/core/interface/file/attachment.php?id=7600)

8

Maybe you turned the contrast pot? Or maybe I am completely off with my guess. But simply updating MIOS won’t kill an LCD.

9

No. I don’t turned the contrast pot, when display died, but now this is not important, VFD is dead. =(((

Any way thanks a lot for yours answers.