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Screen does not work

Posted: Sun Jun 23, 2019 12:21 pm
by Rowi
Hi I bought a screen PD035VX2 from Aliexpress.

Was kind of a mess because the vga board they sent me was 12V and for a 7inch display (https://de.aliexpress.com/item/32845064 ... 4c4dOE3KqO). Ordered another Controller for the display (https://www.ebay.de/itm/VGA-AV-LCD-Driv ... 1438.l2649).

Now I wired it all up but get no picture on the display. After they really got it wrong the first time I do not know if the display is really a PD035VX2 (only think strange is the ribbon cable which seems to be longer than normal).

What can I do?
The wiring seems fine to me.
There are 5V on the VGA Controller. So it is not a power problem.

Re: Screen does not work

Posted: Sun Jun 23, 2019 1:46 pm
by Rowi
On the ribbon of the screen "TCA-C ICHIA 0738"

Re: Screen does not work

Posted: Sun Jun 23, 2019 2:33 pm
by Rowi
As a note: I removed the on and off buttons (separate board). Maybe the screen just does not turn on. Can I jumpwire this 3,3V->power on last picture)?

Re: Screen does not work

Posted: Mon Jun 24, 2019 12:17 am
by VeteranGamer
first off.....

I would try attaching/connecting a battery to Helder PSU (it needs a battery connected to run/function properly)
also
Helder PSU has two (2) separate power (5v/GND) output connections....
these can both be used....
one for the RPi and the second for the LCD....

you also just need to connect the one composite connection (either CBSV1 or CBSv2)
there is also NO need to GND it (you already have a GND connection for the power)


and most importanly
(this is where you've tripped up)

you need to set it to composite using the button board


more info can be found here about this.....


https://www.sudomod.com/forum/viewtopic ... t=80#p5710


NB: all the info is already present on this forum.... if people would only use the search functions.....
(and that age old saying..... fail to prepare..... prepare to fail.... do your research before attempting anything)






.

Re: Screen does not work

Posted: Mon Jun 24, 2019 12:25 am
by Rowi
Hi thanks a lot. We removed the plug for the button board. Does this setting have to be done only once? then we will solder it again to the button board. Or do I have to let the Button board be in the build :(

I Used the Powerdistribution of Tinkerboy V3. Do not think I have to do it via helder -> Helder PSU to Tinker -> Tinker to Display and PI

The battery not visible on the picture was soldered afterwards and 5V was available on the VGA Board.

Re: Screen does not work

Posted: Mon Jun 24, 2019 12:27 am
by Rowi
Is it possible to connect the 3,3 V of the VGA board with a own button in between to power and to source on the VGA Board so you do not need the Button board.

Considering Search function -> I tried... but I am confused about other reports throughout the Internet about this screen which seems to work right out of the box as we did it..

Re: Screen does not work

Posted: Mon Jun 24, 2019 12:34 am
by VeteranGamer
Rowi wrote:
Mon Jun 24, 2019 12:25 am
Hi thanks a lot. We removed the plug for the button board. Does this setting have to be done only once? then we will solder it again to the button board. Or do I have to let the Button board be in the build :(

I Used the Powerdistribution of Tinkerboy V3. Do not think I have to do it via helder -> Helder PSU to Tinker -> Tinker to Display and PI

The battery not visible on the picture was soldered afterwards and 5V was available on the VGA Board.


Helder PSU has two out puts......


Untitled-1.jpg
Untitled-1.jpg (130.07 KiB) Viewed 6264 times


there is NO reason NOT to use them.....
to get the most out of what you have....
I would recommend/suggest to use the both (as Helder as specified..... 24AWG)


as far as I can see....
once you've set it to the composite you should be able to remove the button board.....


I would highly recommend having a good look through this post/thread
alot of the issues you may face or come up against may already have been posted and resolved....


https://www.sudomod.com/forum/viewtopic ... =120#p1288



Rowi wrote:
Mon Jun 24, 2019 12:27 am
Is it possible to connect the 3,3 V of the VGA board with a own button in between to power and to source on the VGA Board so you do not need the Button board.

Considering Search function -> I tried... but I am confused about other reports throughout the Internet about this screen which seems to work right out of the box as we did it..

once you have everything set....
you don't need the button board...


again have a good look through this post/thread

https://www.sudomod.com/forum/viewtopic ... =120#p1288



NB: if you used the search function on this forum you would have come up with the post/thread I've linked (thats how i got it)
IDK about other the stuff on the internet....



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Re: Screen does not work

Posted: Mon Jun 24, 2019 12:39 am
by Rowi
Thanks...but turning the Screen on seems to bei a Button I will still need. Will Take a Look into the threat

Re: Screen does not work

Posted: Tue Jun 25, 2019 3:10 am
by Rowi
What does the controller board actually do? 3,3V on the other pins for + - source and so on ?

Re: Screen does not work

Posted: Tue Jun 25, 2019 10:05 am
by Rowi
So I wired the controllboard but the screen does not react to anything I do (Voltage is ok everywhere)... Source, Power On - Just does not care.
Getting really frustrated :) and do not know anything what I can do now.