PSOne No Color

Surfrock66 · Post by **Surfrock66** » Tue Feb 07, 2006 1:51 am

Ok, I'm really stumped on this one. I've asked before and done tons of both prodding and research, but I can't figure it out. My PSOne screen won't show my 64's color. I have reason to believe the N64 is fine (since composite outs still show color to my TV) and the PSOne screen itself is fine (since the vol indicator still shows up green) All I can think of is that the signal decoding for the composite video is messed up somewhere. Can anyone help me trace this circuit with some form of schematic? I've seen some breakdowns of the chips, but the video processing has me stumped and that's the only thing keeping me from being done with this project.

Harshboy · Post by **Harshboy** » Tue Feb 07, 2006 6:07 am

why don't you try an s-video mod.....or maybe attempt the rgb mod. I don't see how your screen is screwed up........maybe you droped solder onto the board...maybe the ribbon cable is loose. Just look over it.

Post by **marshallh** » Tue Feb 07, 2006 7:50 am

First, I'm going to ask: What kind of power supply are you running it with? Electronics tend to do weird things at low voltages.

Kurt_ · Post by **Kurt_** » Tue Feb 07, 2006 4:46 pm

I had that same problem. I had the verge screen, and I poked at some wires and now it works fine.

I also had a similar problem before that one, where the screen only turned colour when the sound was loud. It was due to the removal of the transformer. I had to add a few capacitors and it worked.

Surfrock66 · Post by **Surfrock66** » Wed Feb 08, 2006 11:55 am

Sorry, the forums are messed up or I'd have responded sooner.

Where did you put the caps in to make it work on the PSOne screen?

The power isn't the problem, I used both the PS it came with and then an DC-DC converter (which actually is putting too much voltage through, I measured the AC adaptrer that came with it and it was putting out 7.86 V though it was labeled 7.2, so I'm using an 8V DC-DC converter that's actually putting out 7.92, if .06V is the problem I'll be damned.) and the problem exists for each. As I said the composite outs are fine, so I'm not sure. I'll try poking some wires, but like I said a diagram would be fine.

The S-Video idea sounds promsiing, I'll try that when I get some time. Otherwise, I asked this before and no one knew, for the PSOne mod they say to bridge a cap on the back of the board to adjust the brightness and I knocked the one next to it (to the right) I soldered it back on and it is connected according to my continuity tester but I don't know if I burned it out with heat or something, so if anyone could test it's value I would try to replace it. It's the one immediately to the right when the transistor space is at the top, right below the RF-Crystal lookin thing.

Harshboy · Post by **Harshboy** » Wed Feb 08, 2006 2:20 pm

wut kind of soldering iron did you use? But i bet it's ok....S-Video is very tuff mod (for me atleast, i'm 13 and i can't solder small stuff)

Kurt_ · Post by **Kurt_** » Wed Feb 08, 2006 2:24 pm

My fix will only work if you have the VERGE screen.

There's a seperate little pcb away from the PS1 pcb. It's attatched along the bottom where you put in the 7.5V. There's a big 3.7 ohm resistor with a cloth sleeve on it. Unsoldr it. Then put 2 1000mf or so (I didn't have less to try, it might work with less) in the spots labelled on the pcb. THen it should work.

Once again. Only on the VERGE screen.

superdeformed · Post by **superdeformed** » Wed Feb 08, 2006 4:23 pm

Surfrock66 wrote: The S-Video idea sounds promsiing, I'll try that when I get some time. Otherwise, I asked this before and no one knew, for the PSOne mod they say to bridge a cap on the back of the board to adjust the brightness and I knocked the one next to it (to the right) I soldered it back on and it is connected according to my continuity tester but I don't know if I burned it out with heat or something, so if anyone could test it's value I would try to replace it. It's the one immediately to the right when the transistor space is at the top, right below the RF-Crystal lookin thing.

I believe that cap is part of an oscilator for setting a reference frequency on the encoder, so I think you would have bigger problems than missing color if there was something wrong with it. The "example" circuit in the encoder's data sheet doesn't give an actual value for it, but I can try and find one of my old meters to check it. As for S-Video, after going over the datasheet a bit, it doesn't seem like it's actually possible without switching the encoder into component mode.

Kurt_ wrote:There's a seperate little pcb away from the PS1 pcb. It's attatched along the bottom where you put in the 7.5V. There's a big 3.7 ohm resistor with a cloth sleeve on it. Unsoldr it. Then put 2 1000mf or so (I didn't have less to try, it might work with less) in the spots labelled on the pcb. THen it should work.

Are you talking about the little power input board on the "PS2" version of the Verge screen? If so, the two "missing" caps are for stability. 1000uF (I really hope you didn't mean 1000 milli farads

) is fine for C3, but a bit too much for C2. The data sheet recommends 47uF or more where C2 is (between output and ground). On the one I have, there was actually a 1000uF cap already soldered on to the power connector between V+ and ground, which is what the C3 space is there for. It seems like the people who repackaged these screens didn't really know what they were doing when they put everything together...