PSone screen problem: On > Brighter > White > Off

khaag · Post by **khaag** » Fri Dec 28, 2007 7:18 pm

I saw bacteria had the same problem, but it doesn't say how he solved it in his thread.

I am running my Sony PSone screen off 7.4V 5400mAH Li-poly batteries. When I turn it on, I get video (I have a set of RCA jacks hooked up), but after about 1 or 2 seconds, the screen's brightness grows, then turns pure white, and then goes black.

Does anybody know how I could fix this? When I power it using the wall adaptor, the picture's color is inverted.

khaag · Post by **khaag** » Fri Dec 28, 2007 10:23 pm

Here's the link to Bacteria's thread:

http://forums.benheck.com/viewtopic.php ... ite+screen

bacteria · Post by **bacteria** » Sat Dec 29, 2007 5:02 am

I have a feeling it was to do with connecting the grounds together between the console and PSone screen. As I recall, the screen goes whiter to bright white to black (screen off) if there is a problem getting the video signal.

The other reason it happens is if there isn't enough juice in the batteries. On my GBA BigBoy project, (I didn't have the batteries in parallel as I should have done) I knew if the Transverter lost power the image would stay on the PSone screen, if the PSone screen was losing battery power the screen got brighter and brighter before going off.

Basically, I would say either the battery isn't providing enough (no issue with the cell you mention of course, unless it didn't charge properly or is faulty?) - using mains power to power the screen will confirm or deny this - a different result would indicate a problem with the battery: or it could be no grounding between the PSone screen and your console? Remove all the wiring to your PSone screen except video, ground, power.

I believe this was the answer. It was certainly nothing to do with what people suggested on my thread about speakers, heat, whatever. The PSone screen does not get hot, after all it is designed to be in a small sealed space with no airflow and the speakers only provide a signal - I used 55mm 8ohm speakers without any issue.

Keep us updated and how you get on!

Kurt_ · Post by **Kurt_** » Sat Dec 29, 2007 11:39 am

I'm pretty sure that when the PSOne had low batteries, the image gets skewed (usually with the extra current used from sound), and sometimes just wavy.

Is it the actual image or the backlight? Like I've said before, LED Mod it!

I just thought of something. If I recall, somewhere, either on MSN or in another thread, you said that you connected +5V to pin 13. If that isn't my imagination, then there's your problem! It should be Connector 1 (LCD side up), pin 12 (the last one)

khaag · Post by **khaag** » Sat Dec 29, 2007 1:44 pm

Thanks for the input guys.

@Bacteria - I am going to try to recharge the batteries. I just have to hook up my protection circuit so they don't explode

@Kurt_ - I guess I made a typo when I wrote that. The +5V is actually hooked up to connector 1 pin 12. I tested it again, and after looking closer at the screen, the image IS still there. It is just the backlight that turns off. When I press the brightness/volume controlls, you can faintly see the adjustment bar appear on screen.

@Anyone who reads this and can tell me the answer - If I hook up my protection circuit like this, when the charging is complete, will the LED turn off?

Kurt_ · Post by **Kurt_** » Sat Dec 29, 2007 2:30 pm

The LED will never turn off.

khaag · Post by **khaag** » Sat Dec 29, 2007 2:34 pm

Well then what does the protection circuit do? I thought it stops current from going to the batteries when they are fully charged. Would this not prevent current going to the LED too?

Kurt_ · Post by **Kurt_** » Sat Dec 29, 2007 2:40 pm

No, it's essentially making a short in the batteries. Try one at P+ and P-. I'm not sure about that. Doesn't your charger have an LED indicator? Mine went green when the batteries were charged, red/yellow/green fade (depending on charge) when it wasn't.

khaag · Post by **khaag** » Sat Dec 29, 2007 2:48 pm

Ok I see what you are saying. What if I put it on the + wire in between B+ and the positive terminal on the battery in series instead of parallel. This would act as a "switch" that is always open correct?

Kurt_ · Post by **Kurt_** » Sat Dec 29, 2007 3:05 pm

I don't see that working either. It'll have a potential difference of zero when charging, and possibly always. Truthfully, I would leave a little LED until you're done everything else.

bacteria · Post by **bacteria** » Wed Jan 16, 2008 1:38 am

On topic, I have confirmed the PSone screen gets bright>white>off when there is no video signal present/working.