thak
Posts: 51
Joined: Wed Apr 10, 2013 6:22 pm

Re: Modifying a 3.5" car display for USB power.

Wed May 21, 2014 4:21 am

Hi!

Nop, but i tried to run it without any modifications on 5v (USB) and is flashing...
So i think it's possible... Just need to know how :)

Stuupy
Posts: 3
Joined: Tue May 20, 2014 7:07 pm

Re: Modifying a 3.5" car display for USB power.

Wed May 21, 2014 4:45 am

Hopefully, someone will come up with a solution? :D


doosen11
Posts: 1
Joined: Wed May 28, 2014 3:18 pm

Re: Modifying a 3.5" car display for USB power.

Wed May 28, 2014 3:54 pm

Hi, I am NOT using a raspberry pi, but I am using another device running on 5v (Atari Flashback 2 (I am making a handheld system with it)) I am having issues using the 3.5" LCD monitor described in this posting, as the board does not match the ones shown. When I power the screen from 5v I get the Atari Flashback main menu, but it is black and white, and grainy. When I select a game from the list the image starts rolling (sorta like an old TV set that isn't tuned to the right channel) When I try 12v from a separate battery supply, (12v to the screen 5v to the flashback) I get nothing on the screen. What is going on? This is for my (highschool) senior capstone project, and its due next week, so any help would be greatly appreciated. (I cant post pictures now as I am sitting in class)

kerm64
Posts: 1
Joined: Tue Jun 10, 2014 8:40 pm

Re: Modifying a 3.5" car display for USB power.

Tue Jul 01, 2014 5:53 pm

The original link posted in this thread now links to the latest model of the same screen. I have mine running off of 5V from my pi. I used a voltage meter to locate the 5V regulator, then soldered directly to it. My soldering job was a bit messy (I don't have a good iron) but it works perfectly.

EDIT: I don't know what happened... suddenly my screen is black and white and my pi doesn't finish booting. I'm currently running the latest version of RetroArch. Reloading the image fixed it not booting, but the black and white is really annoying. Help!

MicroByte
Posts: 7
Joined: Wed Jul 09, 2014 6:46 pm

Re: Modifying a 3.5" car display for USB power.

Thu Jul 10, 2014 8:34 pm

I just ordered one of these backup monitors from Amazon, but had a question in the meantime. what are the dimensions of the controller board? Also, what is the rough width of the board and LCD when folded together?

I plan on trying to use this for a portable and wanted to see which way it might be able to fit.

MicroByte
Posts: 7
Joined: Wed Jul 09, 2014 6:46 pm

Re: Modifying a 3.5" car display for USB power.

Tue Jul 15, 2014 3:13 am

Has anyone cut off the 3 buttons on the board? I need to shorten the board and the best option would be to just cut the board where the buttons are located.

Darkwolf896
Posts: 1
Joined: Wed Jul 30, 2014 7:53 am

Re: Modifying a 3.5" car display for USB power.

Thu Jul 31, 2014 10:41 am

I need a little help with my screen, I bought this one http://www.amazon.com/3-5-Inch-TFT-Moni ... 0045IIZKU/ and the board appears to run on 3.3v instead of 5v. The capacitors are 3.3v when powered on.
I removed it from the frame for a portable project, Here it is on 12v and the pin-outs. The board is labeled 3.3v however when applying 3.3v to the unused points the screen doesn't work. I've also tried soldering directly to the capacitor's positive side.
I'm not really sure what to do now.
Image
Image

MuNk
Posts: 2
Joined: Sat Aug 02, 2014 12:27 pm

Re: Modifying a 3.5" car display for USB power.

Sat Aug 02, 2014 9:05 pm

Karamell wrote:I did it similar without removing anything:

Image

The big advantage is, that you can do this without any advanced soldering skills. :)

The settings with:
framebuffer_width=320
framebuffer_height=240
overscan_left=-30
overscan_right=-30
overscan_top=-30
overscan_bottom=-30
worked very well for me, thanks for sharing this!

This works a treat, got the same screen off Amazon, and this made it super easy, nice not having to desolder anything.

pibo
Posts: 1
Joined: Tue Aug 12, 2014 12:10 pm

Re: Modifying a 3.5" car display for USB power.

Tue Aug 12, 2014 1:02 pm

selorami wrote:
kiloofblow wrote:
kiloofblow wrote:I
ACT4060A - http://www.alldatasheet.com/datasheet-p ... 4060A.html
Is there anything else I should look for on the board as fa a 5v connection?
Image
This is the board. Has anyone seen this version yet?
This might be late for your problem, but for anyone else with same board:
I got my display today and first thing I did was taking it apart. It had exactly same PCB design. Here's what I did to make it work with 5VDC:
Image

The ACT4060A is adjustable DC/DC converter with output adjusted to 5V (with external resistors). I removed the inductor between ACT4060A and output capacitors, just in case if ACT4060A doesn't like getting voltage to the output without input voltage. While I was at it, I also removed the IC itself and diode next to the inductor, but that isn't necessary... Did it to get some parts for future projects.

I haven't tested the power consumption, but I quess it's little less than before the modification (package stated max 2W).

Picture isn't perfect, but good enough for 20GBP portable display.
I have sucessfully modded this display type using your instructions, but hit a trap: If the power supply is bad (I tried two different 5V USB wall warts) the screen will turn on for a split second, then turn off for 1-2 seconds. After connecting the screen to a good power supply or directly to the 5V GPIO pin on the Pi it worked flawlessly.
I removed the input diode D3 too, which should result in less voltage drop on the 5V line. Note that you will now probably kill the screen if you swap supply voltage polarity though... The screen now draws ~400mA at 5V and even works as low as ~4.2V supply voltage. There is a bit of dot crawl, but overall the picture is ok.
Side note: I tried shorting the switches (K1-3) on the right side, but nothing happened, no menu etc...

In config.txt I set the framebuffer to 480x272 and set the overscan left/right/top/bottom to about -16 to -24 (experiment till screen is filled). Then I used "sudo dpkg-reconfigure console-setup" to set the console font to "UTF8", "Guess", "VGA", "16x28". The console is big, but perfectly readable now.
screen_conversion_5v_web.jpg
screen_conversion_5v_web.jpg (63.12 KiB) Viewed 5110 times

Shadus
Posts: 1
Joined: Tue Aug 12, 2014 10:35 pm

Re: Modifying a 3.5" car display for USB power.

Tue Aug 12, 2014 10:40 pm

Do we know where the shield from the Comp. Video cable is connected on the device? Is it connected to common ground?

Methanoid
Posts: 63
Joined: Thu Feb 28, 2013 12:02 pm

Re: Modifying a 3.5" car display for USB power.

Sat Aug 16, 2014 11:39 am

Anyone able to recommend one that works and we can be sure we can get the exact model (ie it comes without a casing so we can see what we are buying)? I found this one that looks right size for my needs but no idea if it would work

http://www.ebay.co.uk/itm/251272431211

kammron
Posts: 3
Joined: Wed Dec 18, 2013 9:52 am

Re: Modifying a 3.5" car display for USB power.

Fri Aug 22, 2014 4:36 pm

Does anybody know this one here and has an idea what i have to do to run this one on 5 V ?

Image

I bought it from amazon http://www.amazon.de/TaoTronics-TT-CM01 ... bildschirm



Kind regards !


EDIT: i found a 5v Solder Point on the backside of the PCM . I took the red wire from the 12v and solders it on the 5v point . But now nothing's happens and the board is getting very hot . Has anybody a idea what I did wrong :/?

brain1024
Posts: 2
Joined: Sat Aug 23, 2014 10:21 am

Re: Modifying a 3.5" car display for USB power.

Sat Aug 23, 2014 10:27 am

This works for me:

http://www.suckmypic.net/73677/IMG_20140823_145147.jpg
http://www.suckmypic.net/73678/IMG_20140823_145159.jpg

The red wires source is @ 5v. i didnt remove any component from the pcb.

Oeasis
Posts: 2
Joined: Wed Aug 27, 2014 3:46 pm

Re: Modifying a 3.5" car display for USB power.

Wed Aug 27, 2014 4:05 pm

Hey there, I've gone and bought myself a 3.5 inch screen from the link the op provided and it looks like I might have yet another variation ( could be the latest model kerm64 was talking about ). Anyway I thought I'd ask if anybody knows how to approach this before I dive in myself and break something ^-^.

Here's a nice high res photograph (4000 x 3000) to show you what I'm facing here. It's really nice and compact compared to the original ones I've seen posted on here, which is good cause I'm hoping to fit it in a old gameboy. The silver rectangle behind it is the screen.

Image

Thanks in advance :)

boobatron3000
Posts: 1
Joined: Sat Aug 30, 2014 2:05 am

Re: Modifying a 3.5" car display for USB power.

Sat Aug 30, 2014 2:19 am

Since you posted such a nice picture and it seems no one has given you any help yet I decided to register an account to tell you how I modified the exact same board.

The two regulators that are marked AMS1117 their right most pin is connected to the 5 volt bus, one of these pads is the best place to solder your 5 volt line.

The big through-hole capacitor is 12 volt, it can be removed, making this much smaller than some other boards posted here.

sirmodok
Posts: 1
Joined: Thu Sep 18, 2014 1:07 am

Re: Modifying a 3.5" car display for USB power.

Thu Sep 18, 2014 1:20 am

Has anyone seen one like this?
Image
It's super compact compared to the other ones, and it's pretty pretentious too (according to the text on the board that says "Best board for 4.3 inch") I have a few guesses as to how to modify it to accept 5v based on reading this entire post and comparing some of the chips on mine to some in the pictures posted, but I'm afraid to just up and try it myself. I have very little electronic experience. I have put in a few mod chips and such, but always with detailed instructions.

Any help would be appreciated.

nox86
Posts: 3
Joined: Fri Jun 07, 2013 8:15 pm

Re: Modifying a 3.5" car display for USB power.

Thu Oct 09, 2014 9:47 pm

Thanks goes to Oeasis and boobatron3000
Large Image
btw, there is serial port: datasheet, firmware
my lcd: http://www.ebay.com/itm/171329340261
Attachments
lcd_MST703-LF_board_s.jpg
lcd_MST703-LF_board_s.jpg (59.4 KiB) Viewed 4541 times

aukreutzer
Posts: 3
Joined: Wed Oct 15, 2014 9:36 pm

Re: Modifying a 3.5" car display for USB power.

Thu Oct 16, 2014 6:16 pm

Trying to work with this same board but have a question, yes I am totally noob when it comes to this stuff, but I am trying to expand my knowledge base. I have a schematic from someone else that used a different board and want to wire it for my board. I have attached the link below. What I need to know are as follows:


-Where do i need to attach the wire to the LCD/3.3V switching regulator? This picture is on the supplied link


Here is my pic link: http://s36.photobucket.com/user/Shayne_ ... sort=3&o=0

also, the link to the person who made this schematic, just in case I do not have my pictures clear, it is pic 51 out of 52: http://www.xodustech.com/projects/raspb ... boy-pocket

selorami wrote:
kiloofblow wrote:
kiloofblow wrote:I
ACT4060A - http://www.alldatasheet.com/datasheet-p ... 4060A.html
Is there anything else I should look for on the board as fa a 5v connection?
Image
This is the board. Has anyone seen this version yet?
This might be late for your problem, but for anyone else with same board:
I got my display today and first thing I did was taking it apart. It had exactly same PCB design. Here's what I did to make it work with 5VDC:
Image

The ACT4060A is adjustable DC/DC converter with output adjusted to 5V (with external resistors). I removed the inductor between ACT4060A and output capacitors, just in case if ACT4060A doesn't like getting voltage to the output without input voltage. While I was at it, I also removed the IC itself and diode next to the inductor, but that isn't necessary... Did it to get some parts for future projects.

I haven't tested the power consumption, but I quess it's little less than before the modification (package stated max 2W).

Picture isn't perfect, but good enough for 20GBP portable display.
Last edited by aukreutzer on Fri Oct 17, 2014 11:52 pm, edited 1 time in total.

GnobarEl
Posts: 4
Joined: Tue Apr 08, 2014 4:10 pm

Re: Modifying a 3.5" car display for USB power.

Thu Oct 16, 2014 10:07 pm

thedishwasher wrote:Yet another board design (for the 3.5" screen)

Image
Image
Image

I went with the previosly posted method and it works flawlessly.

my config.txt is slightly different though

Code: Select all

overscan_left=20
overscan_right=20
overscan_top=-20
overscan_bottom=-25
Thanks for this tip!
i have the LCD board with version 04 14 - 2013-10-08 and worked great!
thanks =)

thak
Posts: 51
Joined: Wed Apr 10, 2013 6:22 pm

Re: Modifying a 3.5" car display for USB power.

Fri Oct 17, 2014 7:11 am

thak wrote:Hi!

I recently bought a car display, and like all of you, i'd like to run it on 5v.
But the pcb seems to be completly different from the one you've already post.

Image

Image

Could someone help me to run this one on 5v if possible?
Thanks a lot!

Still no clue on how i can run this one on 5V :'( ?
If you need more picture let me know!

GnobarEl
Posts: 4
Joined: Tue Apr 08, 2014 4:10 pm

Re: Modifying a 3.5" car display for USB power.

Tue Oct 21, 2014 4:20 pm

Hi, can you give me the model name of the RED IC?

Try to measure if it have 12v in onde side and 5v on the other side.
Attachments
DSC_0666.jpg
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thak
Posts: 51
Joined: Wed Apr 10, 2013 6:22 pm

Re: Modifying a 3.5" car display for USB power.

Tue Oct 21, 2014 5:00 pm

Hi,

A5269_BM39AQ

Unfortunatly i can't mesure any side of the chip the board is way too much small for my voltmeter :(

Thanks for your help!!

GnobarEl
Posts: 4
Joined: Tue Apr 08, 2014 4:10 pm

Re: Modifying a 3.5" car display for USB power.

Tue Oct 21, 2014 5:08 pm

I believe that is the voltage regulator.
you would need to check the output 5v pin and GND pin.
remove the IC and solder the the 5v and GND pin.

thak
Posts: 51
Joined: Wed Apr 10, 2013 6:22 pm

Re: Modifying a 3.5" car display for USB power.

Tue Oct 21, 2014 5:29 pm

Ok i will give a try this we if i can :-)

Thx for your time and help, i will post the result when it's done!

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