sudomod

Hi guys,

Let me start by saying hi. I've been reading the forums for a while now (thanks for all your help) and can now finally start working on my own build after parts have been arriving over the last couple of weeks.

Unfortunately I am having issues at my first try, which is trying to get my screen to work. I am using this screen: https://www.aliexpress.com/item/3-5-TFT ... 4c4d5UBeel. It worked fine when I connected the cables to the connector on the controller. I then desoldered that connector and soldered cables directly to the board. Ever since, the screen does not show a clear image and clearly shows too much white. Also, the image quality (if I disregard the color difference) seems off.
Since it was my first time soldering in a long long time, I am afraid I damaged the controller board of the LCD. One of the AV connecting pads (right on last photo) came off while desoldering. Does this seem like a "let's order another screen" scenario to you guys?

It all seems to be the signal, since the "AV2" on the top right is showing in the correct color and in good quality.

Dont know much about this but you can search the forums cause there are tons of similar issues regarding a white screen.
throw this into google:
white screen soldering sudomod site:sudomod.com

Thanks for that. I did dig deep in other posts and tried to work with all possible solutions. Unfortunately nothing seems to work. It seems that desoldering the connector was a bad thing to do, and I'm afraid I indeed partially fried the board.

I've ordered a second screen to which I'll solder the wires without desoldering the connector. Nevertheless, if there's anyone thinking this is a fixable issue, I'm all ears!

frits1993 wrote: ↑

Tue May 14, 2019 7:41 am

Thanks for that. I did dig deep in other posts and tried to work with all possible solutions. Unfortunately nothing seems to work. It seems that desoldering the connector was a bad thing to do, and I'm afraid I indeed partially fried the board.

I've ordered a second screen to which I'll solder the wires without desoldering the connector. Nevertheless, if there's anyone thinking this is a fixable issue, I'm all ears!

i'd guess that it's just a poor connection - try resoldering the wires, or try twisting the ground and signal, to strengthen the signal. i think it would be pretty difficult to fry those inputs by de/soldering them.

when i've seen something similar, it's usually that the ribbon cable isn't seated correctly, but i've also had a few times where the ribbon cable had come loose from something in the screen, from just moving it around too much, and it would do similar things, like go all-white, loose a color channel, or just turn off.

I have lifted an AV pads before, and it just worked with the other AV pad. So I would expect that isn't the issue for your white screen. As mentioned above, check your connections. It helps to wire ground directly bedside the AV hole on the pi.

Do you have any actual pics of the wiring on the pi? Also, just an FYI, you have left bunch of exposed wire on the screen wires, I would shorten those up, to prevent accidental touching.

Thanks guys, I’ll resolder some of the connections this afternoon and using the ground next to the AV hole is something I haven’t done before so that’s definitely worth a try.

I’ll post some pics of the results including the wiring on the pi if I keep having same results.

Nu luck, unfortunately. Results are identical. I resoldered all my wires and used TV- as gound.
I also shortened the long wire-endings.

These pics show the wiring from board to pi.

those connections look ok to me, and your wires are pretty short, so i'd guess it's not a signal strength problem, unless the solder connection is just bad on the pi or something.

my best guess from what i've seen with those composite screens is a problem with the ribbon cable. you could try re-seating it in its connector, but like i mentioned above, a few times i've had the ribbon cable just jiggle loose from something in the screen, and had it act similarly (which, maybe could be fixed, but i just move on to a working one).

Yeah, it may then be the ribbon cable which has disconnected in the screen. I've re-seated the cable in it's connector at least 10 times just to be sure, and don't see any possible improvement there.

It could then have happened in the couple of days in between my first wiring-test (when it worked perfectly) and my first soldering (I had not tested it again the minutes before soldering). Maybe I had laid it down in a way which disconnected something in the screen, even while being very careful with it.

Anyway, thanks for the help. A new screen is on the way and I'll have a go at connecting my current screen into the fresh controller to see if indeed it's the ribbon cable which is the problem. ETA of the new screen is in ±10 days, I'll post an update on my findings.

frits1993 wrote: ↑

Fri May 17, 2019 11:20 am

Yeah, it may then be the ribbon cable which has disconnected in the screen. I've re-seated the cable in it's connector at least 10 times just to be sure, and don't see any possible improvement there.

It could then have happened in the couple of days in between my first wiring-test (when it worked perfectly) and my first soldering (I had not tested it again the minutes before soldering). Maybe I had laid it down in a way which disconnected something in the screen, even while being very careful with it.

Anyway, thanks for the help. A new screen is on the way and I'll have a go at connecting my current screen into the fresh controller to see if indeed it's the ribbon cable which is the problem. ETA of the new screen is in ±10 days, I'll post an update on my findings.

yep, that sounds like what's happened to me. even trying to be careful, it seemed that just the bending back and forth as I'm moving it or putting it in the case was enough to pull it loose, or whatever happened in there. the pitfalls of using cheap parts i guess. i'm sure that's what happened on mine, since i could kind of shift the cable around and get the image/color to come back or go away.