PSone screen question

Rekarp · Post by **Rekarp** » Wed Aug 13, 2008 3:06 pm

I know the PSone screen has two 7805s on and and I have a question about those. I have read that the screen only needs the 7.4V for the sound amp correct? So if I was to bypass the 7805s and input 5V I would still get a picture?

ShockSlayer · Post by **ShockSlayer** » Wed Aug 13, 2008 3:55 pm

I'd say its highly likely. But at the same time, You'd probably get a lot of noise on the screen, if the shared the same +5v line. So, you'll probably end up using a 7805 anyways. If I'm not mistaken, I read somewhere here that the 7805s had something to do with the picture, and noise. I think it was either that supersegasonicfan(cuz i dont remember) or timmeh who had problems with it.

SS

sam_thornley · Post by **sam_thornley** » Mon Aug 18, 2008 4:41 am

The PSone screen requires at least 7v to start up. The AN2526NFH video/LCD controller and the CCFL inverter run directly off the 7.5v line. The IC can run at 5v but it has been set up internally to run a 7.5v for use in this screen. Any voltage lower than 7v and the IC looses sync and the image on the screen will get whiter and whiter then shut down. One 7805s on the psone screen powers the WiseView OSD chip plus an op-amp and an eeprom. Wile the other 7805 powers the audio amp and LM1881 sync separator. A few people have tried to run the PSone screen off 5v before, but its not possible because parts of the screen require 7.5v to function properly.

bacteria · Post by **bacteria** » Mon Aug 18, 2008 9:51 am

Nice comprehensive reply!

Rekarp · Post by **Rekarp** » Mon Aug 18, 2008 9:54 am

sam_thornley wrote:The PSone screen requires at least 7v to start up. The AN2526NFH video/LCD controller and the CCFL inverter run directly off the 7.5v line. The IC can run at 5v but it has been set up internally to run a 7.5v for use in this screen. Any voltage lower than 7v and the IC looses sync and the image on the screen will get whiter and whiter then shut down. One 7805s on the psone screen powers the WiseView OSD chip plus an op-amp and an eeprom. Wile the other 7805 powers the audio amp and LM1881 sync separator. A few people have tried to run the PSone screen off 5v before, but its not possible because parts of the screen require 7.5v to function properly.

Well I always LED mod so the CCFL gets cut off anyways.

The AN2526NFH. You said its set up internally? So theres no chance of changing a resistor value or what not?

edit// looked at the spec sheet. Needs 7.5V and 5V to run.

sam_thornley · Post by **sam_thornley** » Mon Aug 18, 2008 5:25 pm

bacteria wrote:Nice comprehensive reply!

Thanks

Rekarp wrote: The AN2526NFH. You said its set up internally? So theres no chance of changing a resistor value or what not?

edit// looked at the spec sheet. Needs 7.5V and 5V to run.

Well its not quite setup internally, its controlled by the WiseView IC via an I2C bus. And yeah i forgot that the AN2526NFH requires two separate voltages

One for its chroma decoder and one for the main TFT LCD circuit or something like that.