Crazy LCD screen came back

[waterstrum]

Very odd story...

I've been running the DM4800 for years.
The LCD screen just kept on working.
My eyes needed a bigger screen, so I got the 2seemy and it is great.
About a year after installing 2seemy, the onboard LCD went in to the vertical stripe mode.
Almost illegible.
I was happy that I had installed the bigger screen and in fact, didn't miss the tiny one.

Just today, the LCD screen returned to normal and is working as new.
What is up with that?
I'm wondering how long it will last.
It's fun to see it again.
Pretty small, but fun to have the original screen back.

Anybody know why this would happen?

 

[Arjan P]

Interesting. Especially since the failure mode we're all used to is the horizontal stripes - and I don't think there's any coming back from that. Vertical stripes therefor must have a different cause which I don't know.. The horizontal ones are AFAIK a result of the flat cable glue letting go on the sides of the screen (not sure if I use the correct wording). Good to have your screen back again though!

 

[TimV]

I’m going to keep an eye on this thread because I have the same problem and thought using the 2Seemy board would fix it...alas, it didn’t. I think it it has something to do with the main board but I just haven’t had a chance to tear into it. I wish I could find a “real” service manual with actual schematics of the main board. The service manual floating around on the interwebs, which I have, is too vague and isn’t detailed enough. Tascam is little help.

 

[Arjan P]

So @TimV, do you mean you also get the vertical lines on the 2Seemy display? That would seem very similar but not the same as @waterstrum. Weird.

 

[TimV]

Arjan, Yes those lines are on both the display and the monitor plugged into the 2Seemy card. It leads me to believe there is something up with the video section of the main board (or cabling/connections). Unfortunately, there is no documentation that I can find that even hints as to where the video is generated on the main board. One thing I have wanted to check is the actual flat cable running from the main board to the 2Seemy board.

It's possible that something is bad on that cable. The other thing is it's possible that the previous owner, when he was installing a new aftermarket display due to horizontal lines, may have knocked one of the many connectors on the main board (or any of the other boards in there) and it's cocked off causing a partial connection of signals. I know I did that when I was installing the 2Seemy card and knocked one of the connectors on the power supply which did all kinds of interesting things. I started to panic that I had screwed up my board but retraced where my hands had been. That's when I saw one of the connectors on the PS partially seated. I pushing it back down and all went back to normal. I'm hoping I'll find something like that when I start looking into the vertical lines problem.

I have been meaning to reach out to the folks that designed the 2Seemy board, hoping that they may be able to give me some ideas on where to start to look. I figured someone there has to know something about the video as they designed the 2Seemy card to work from that section of the main board.

I have a picture of the monitor screen somewhere. I'll post it here when I get a chance.

 

[Arjan P]

Yeah hopefully the folks at 2Seemy can help you, they seem very helpful, so good luck there.