PCEGT replace with 3.5inch TFT LCD

[compil3r]

Thanks a lot for the reply turbokon. I will play safe with the one that has the composite video in.

Also, I am having trouble finding a resistor kit that has both the 6.3k one and the 75 ohm one. The closest one is this, that has all the rest:

http://www.ebay.com/itm/1-4-W-Watts-Resistors-Series-87-Value-Kit-0-10M-870PCS-/320955062830?pt=LH_DefaultDomain_0&hash=item4aba699a2e

And I've been looking for the 6.3 and the 75 one separately (on eBay) without luck on the 6.3k one. So, any advice on where can I get these? Or maybe I can use other similar?

[compil3r]

*bump

[turbokon]

thesteve can chime in but I think the 75ohm is important but the 6.3k not so, you can go +/- a few 100ohm without a noticeable differents in the color output.

[Keith Courage]

I think I just went with a 6.2k on ebay last time cause I ran into the same issue. Close enough http://www.ebay.com/sch/i.html?_trksid=p2047675.m570.l1313&_nkw=6.2k+resistor&_sacat=0&_from=R40

[compil3r]

Good news! I've just found them on a little but crowded electronics shop in downtown around here. I bought both 6.2k and 6.3k just to be sure.

Thanks guys, I will start this as soon as I get the LCD

[turbokon]

Good luck with the LCD as all will not work with this mod. My last three LCDs doesn't work for the mods and I bought them from the same place.

[compil3r]

Good luck with the LCD as all will not work with this mod. My last three LCDs doesn't work for the mods and I bought them from the same place.

Oh man, I hope not. What specific store/seller/model do you recommend, to make sure it works?

Thanks!

[compil3r]

*bump*

[turbokon]

I don't know  the model/part number but the I usually buy them from here but the last batch I bought doesn't work with the mods.

http://bit.ly/W16BHh

[roflmao]

I think that's the same one I picked up based on chat with thesteve and he's run into issues getting it to work in my express as well.  He mentioned to me he purchased a few recently from them also and they didn't work either, though it sounded like he was working on a fix.  I haven't heard from him in a few weeks, though, so hopefully things are going well.

[compil3r]

Ok, the LCD has just arrived. First thing I did was test it and all I get is a white screen... sound works, but no video. I haven't made the TE mod yet because I'm still waiting for resistors on the mail, but I tested it connecting a sega genesis model 2, and I don't get any video.

So, when you say the screen was not working with your mod, what did you get? black screen, white screen, scrambled video?

I am trying to figure out if the LCD I received is in fact defective.. :S

Thanks!

[turbokon]

I only get a white screen on mine.

[compil3r]

So maybe it's not that they don't work with the mod, but they are defective? It is supposed to take any video signal in, right?

[turbokon]

Not nessecery, these are design to be used with 12v system in car. The TE uses way less voltage. Some will be glitchy and some will not work at all at this lower voltage.

[compil3r]

I am testing it with 12V. Any video I put, shows the same white screen. I will ask the seller, maybe we are getting defective units!

[compil3r]

Seems the seller admits there's something wrong with *all white* displays. They replied to me asking if I've adjusted the brightness wheel on the side (duh! of course) and also requested a small video of the problem. I will send it, and maybe these end up being defective units...

[turbokon]

I just tested all the LCDs with a nomad and they all work. They just don't work with the TE mod.

[compil3r]

Damn, mine gives all white with any video source

[thesteve]

im working on the issue
when i have a good solution i will post it.
also the vender wants a video of the prob

[compil3r]

Glad I'm not the only one with this weird issue... I will send them the requested video soon, didn't had the time yet, I blame Ys IV english translation

[compil3r]

Hey thesteve, do you have a solution for the all white screens yet?

Thanks!!

[Keith Courage]

All white sounds like there is a problem with one of the pins for the HU card slot or a more major problem of a bad trace or Chip somewhere on the board. I'd check the Hu card slot first.  I had to repair an express by swapping in the HU slot from a doner TG16 since a few pins had been bent and destroyed somehow.

[turbokon]

Keith, we have the determined that some of the lcd's won't work with the TE's LCD mods. According to thesteve, it's a resolution issue.

[Duo_R]

Put the screen in a Nomad ;-)

Hey thesteve, do you have a solution for the all white screens yet?

Thanks!!

[compil3r]

In my case, the problem is that the screen is not working with ANY video source... even if I connect a DVD player, there is only sound and all white video. Is expensive for me to send it back to china, so I just ordered another one from other source, checking that is other brand and seller.

Let's see how it goes!

[Duo_R]

Ahh I thought it was just the TE having issues. Let me know when you guys find a good replacement.

[Duo_R]

Wait why can't you just split the CV signal?

If you want to do both LCD and comp vid out to tv, you'll need two tranx, one for each.

[turbokon]

The composite vid out to TV won't be bright enough when using only one transx.

[thesteve]

the reason for 2 tranx is so a shorted output, doesnt kill the internal sig, and to maintain the brightness

[Duo_R]

So your saying a 2nd transistor is used in the circuit?

[thesteve]

i use a second drive circuit for my AV out, because the stereo AV out shorts the vid pin to ground when using a headset.
my drive circuit is designed for it
i use a 1k resistor from the first transistor emitter (screen out) to the AV transistor base
220 ohm from 5V to collector , emitter out
during emitter ground, the 1K keeps the video good, while the 220ohm keeps the transistor safe

[Duo_R]

if the headphone jack was replaced with a true mini AV out port a 2nd NPN wouldn't be used correct? I would think the same Video line could be split to screen / AV out if there wasn't a shorting issue. I have one of those exact ports that I can use.

[turbokon]

You would still need the 2nd transistor.  If you plan to use the stock LCD, then you would only need one.  Where did you get this port you're planning on using?

[Duo_R]

I sourced from another device, probably a DVD player can't remember.

[Duo_R]

out of curiosity is anyone testing these on Turbografx / PC Engine / Duo systems prior to opening them up? Do they also display the white screens on those systems?

Hey thesteve, do you have a solution for the all white screens yet?

Thanks!!

[turbokon]

That wouldn't be a bad idea. Chances are if they work on a duo/tg16/pce setup with comosite out then it will work with the TE LCD mod.

[Duo_R]

Exactly that way if you get one that doesn't work you can ship back.

Just need to get an external power supply to boot the screens up.

[turbokon]

I use your TE battery mod as the power source when I'm testing these LCD.

[Duo_R]

Nice

[thesteve]

yes i was testing on the TG16
same results

[pcengin4eva]

I did the mod so far ... i liftet 19 25 29 32 39 and grounded them . I connected 20(CB)to 27k ,26(B-Y)to8.2k ,33(R_Y)to6.3k and 40(Y) to4.7k ( i didnt lift any of those pins) . Afther the resistors i connected all of them to BASE of a BC337 NPN transistor (on whichs Collector 5v from the upper side , measured and ok) . Emitter goes to 75 ohms and after that to the lcd´s video in . LCDs GND goes to GND naturally . All i get is a very weak picture .

Whats wrong ? Wrong transistor ?

[turbokon]

I did the mod so far ... i liftet 19 25 29 32 39 and grounded them . I connected 20(CB)to 27k ,26(B-Y)to8.2k ,33(R_Y)to6.3k and 40(Y) to4.7k ( i didnt lift any of those pins) . Afther the resistors i connected all of them to BASE of a BC337 NPN transistor (on whichs Collector 5v from the upper side , measured and ok) . Emitter goes to 75 ohms and after that to the lcd´s video in . LCDs GND goes to GND naturally . All i get is a very weak picture .

Whats wrong ? Wrong transistor ?

You sure you're getting 5v to the transistor? Maybe the LCD you're using doesn't work well with 5v.

[pcengin4eva]

No 5V go to the NPN Collector of the Composite signal

Ipowered the LCD with external 9V for testing . It works perfect with my CoreGrafx Video signal . But not with the TurboExpress Composite i created

[turbokon]

No 5V go to the NPN Collector of the Composite signal

Ipowered the LCD with external 9V for testing . It works perfect with my CoreGrafx Video signal . But not with the TurboExpress Composite i created

Where are you tapping 5v for the transistor?

[pcengin4eva]

Where are you tapping 5v for the transistor?

From Q502 collector , upperside , measured 5v with multimeter and ok

[turbokon]

That should work, check your connection on pin 40, that's is the luma. Make sure it's not bridge with pin 39 or loose.

[thesteve]

Weak how?, recheck your resistor values and transistor pinout

[Duo_R]

Any new LCDs working? I think my TE is done with mods, I might feature it on a YouTube review hopefully "soon" which usually means 2 years! Lol

LCD mod, controller mod, switch less region mod and I'm hoping to add in component mod.

I had this on the back burner for a while, it was almost done but something was acting up but finally fixed it today.

[NightWolve]

hopefully "soon" which usually means 2 years! Lol

I have that same problem with my "soons" or "eventually..." ; )

Gotta try to resist saying or hoping to do various things out loud. Heh.

[Duo_R]

Yeah you're totally right!