PanelDue Flashing on and off
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This started happening with my 7" Paneldue (v1.1) yesterday during a print.
On-Off with about 2 times per second. All information is shown and the rest works, incl touch, as it should.Connecting with USB (only, not tested with both connected) and the flickering it gone, so the screen works.
I updated to the latest Paneldue fw but no change. Duet running latest fw too.Checked the voltage on the cable and it read 4.95-4.99v so that seems fine, but I will check this again tonight.
any other ideas?
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Checked voltage "output" from the Paneldue and it goes up and down from 3v to 4.5v and a noticeable buzzing sound is made
every cycle, probably due to the LCD lighting up.Is the PanelDue dead?
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It's unlikely that the PanelDue controller board is dead. Check the 5V supply on the input to the PanelDue controller board at the 4-pin connector. If that is also going up and down, check the 5V supply on the Duet's PanelDue connector too.
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Tested the following now.
Cable from Duet: 4.87v steady
Cable from Duet only Paneldue:- Pin directly: 4.87v
- 5v pin on the pins going to the LCD (LCD not connected): 4.5v
Same 5v pin above when connected to LCD: jumping between ca 3v and 4.5v (flickering)
LCD when power only from USB3.0: ca 4.3v on above pin (not flickering)
LCD when power from both duet cable and USB: 4.3 (not flickering)So something has all of the sudden started screwing with the voltage when it comes from the duet cable only.
My electronics skills are not good enough to say where though.. I see no damaged parts on the LCD.ideas? besides scrap the LCD..
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It sounds like the PanelDue isn't supplying a steady 5v to the LCD, possibly a damaged trace or bad connection.
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Tested the following now.
Cable from Duet: 4.87v steady
Cable from Duet only Paneldue:- Pin directly: 4.87v
Please clarify: were those voltages measured with the LCD connected and flashing (no USB power supplied), or not? And were BOTH of them steady?
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Tested the following now.
Cable from Duet: 4.87v steady
Cable from Duet only Paneldue:- Pin directly: 4.87v
Please clarify: were those voltages measured with the LCD connected and flashing (no USB power supplied), or not? And were BOTH of them steady?
Both above, steady, voltages were without LCD connected.
I just tried checking the pins on the connector on the paneldue (where the cable is directly connected) when connected to the LCD (no USB) and it fluctuates, however it's a more
slow up and down between ca 3.5V and 4.7v. I recorded this and will link it as soon as I'm able to. -
Please don't mind my shaky morning hands.
This is when everything is connected, except USB.
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If the voltage on the 4-pin PanelDue connector is fluctuating, that points to a problem either on the Duet or more likely in the cable connecting the PanelDue to the Duet. Probably a bad crimp connection.
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If the voltage on the 4-pin PanelDue connector is fluctuating, that points to a problem either on the Duet or more likely in the cable connecting the PanelDue to the Duet. Probably a bad crimp connection.
I will take a look at the duet side tonight if I get the time.
But it only happens when the PanelDue is connected to the LCD. If I disconnect the PanelDue from the LCD is stops and just gives a nice stable 4.8-ish voltage.Thinking that perhaps the LCD is bad and messing with the voltage from its side.
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The backlight inverter is responsible for most of the current draw, and it will only start when the voltage is high enough. That explains why the voltage is stable when the TFT panel is not connected.
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Starting to suspect the inverter then. Read that there would be a buzzing sound when it's broken, which sometimes comes from the LCD panel when this is happening.
New 5" needs to be ordered then..
Thanks for the help David, always a pleasure to get your insight!
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I still suspect the cable.
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I still suspect the cable.
I'll check it when I'm rebuilding/re-cabling when my PCB Effector kit arrives
Don't have the cash for a new screen atm anyways
