avatar_G40rocket

CPC 464 SCART Cable doubts & Restoration CPC Keys [Pag. 4]

Started by G40rocket, 23:52, 30 April 15

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

a7mag3ddon

I get a picture but I just have a blue ghost.

VincentGR

Quote from: a7mag3ddon on 20:49, 05 May 15
I get a picture but I just have a blue ghost.

Check your connections again and use a better cable as Bryce said  :(
Then try another diagram.
Does it happens on a std monitor too?

a7mag3ddon

I only have 1 TV. I have a RGB scart to HDMI adapter only.

VincentGR

You sould try that on a ctm644 but I doubt you will see this ghosting there. I bet it is your cable.

Bryce

#29
Is the shield connected to the CPCs ground or the TV. Ideally it should be connected at the CPC end, but not the SCART end.

@VincentGR: The voltage to pin 8 isn't really needed. You can switch to AV yourself. Pin 16 is needed, but this is what my capacitor does.

Bryce.

a7mag3ddon

Just took it apart and looks ground / shield is going to pay n 17. I'll take a PIC.




a7mag3ddon

So, fixed my ghosting issue by using a cable with power pass through. Works awesome now!



seanb

Thats great.
About time you had some success with your amstrad with all the time and money you've put into it.

Really happy for you
Thou shall not question Captain Wrong!

a7mag3ddon

Yeah and my gotek arrived today too.

seanb

I seen on Facebook.
Hope you get that working soon
Thou shall not question Captain Wrong!

VincentGR

Quote from: Bryce on 20:54, 05 May 15
Is the shield connected to the CPCs ground or the TV. Ideally it should be connected at the CPC end, but not the SCART end.

@VincentGR: The voltage to pin 8 isn't really needed. You can switch to AV yourself. Pin 16 is needed, but this is what my capacitor does.

Bryce.

Didn't know that, thanks.

Bryce

Quote from: a7mag3ddon on 17:14, 07 May 15
So, fixed my ghosting issue by using a cable with power pass through. Works awesome now!

Congratulations, what exactly do you mean with "power pass through" ?

Bryce.

a7mag3ddon

Takes power from amstrad PSU, uses it then passes through to the CPC itself. Sorry I wasn't too clear, I knew what I meant ;-)


Bryce

Ah, your problems were probably being caused by a ground loop then.

Bryce.

a7mag3ddon

Still doesn't work on the TV though, picture is even worse like loading bars all over. Not worry though as I want allbmy machines to go through a scanline generator before hitting the scaler :-) going to look awesome.

Bryce

Those "loading bars" really do look like there's noise from a switch-mode PSU getting onto the blue signal. You could try powering the CPC from a different power socket than the TV which might help?

Bryce.

a7mag3ddon

But using all same bits works OK on converter. Would t you expect it to be just the same?

Bryce

If the noise is coming from the TVs SMPSU then the converter might be isolating the TV from the CPC.

Bryce.

G40rocket

Mates, the Scart cable was a "success" however there is a problem.

Without the 100uf capacitor, my image is nice, colored but with some ghost effect/flickering so i added the 100uf capacitor and the image is near to clear really but now it's BLACK & WHITE !!!

What a hell ?

Bryce

Sounds like the capacitor isn't building up enough voltage to trigger RGB (1 - 3V) and the TV is reverting to Composite (0 - 0.4V). Are you sure that the correct signal is connected to the capacitor and that it's the correct way around?

Bryce.

G40rocket

#45
Quote from: Bryce on 11:50, 08 May 15
Sounds like the capacitor isn't building up enough voltage to trigger RGB (1 - 3V) and the TV is reverting to Composite (0 - 0.4V). Are you sure that the correct signal is connected to the capacitor and that it's the correct way around?

Bryce.

Folks, nevermind, the problem was because the scart pin was not making good contact with the TV connectors so now the black & white image is fixed.

With capacitor or without the image has the same quality and for the "image noise" the culprit is my homemade power supply (i used an Tablet ac adaptor [5v 2A] with USB connection, peeled off a usb cable and soldered to a power jack, just for test).

At least i finally tested the Amstrad and power on !

About the scart connector i will buy a premium scart cable because the current one was very cheap (like chinese cables) and the wires are very thin thickness and probably that's the problem for a no perfect image.

Will give you more news and thanks everyone for your help/tips.

PS: Now the final step is treat the yellowing effect in the keys with retrobright method, for example the Enter blue keys are almost grey due the sunlight.

The plastic cases are very cleaned, looks like brand new and i cleaned the dust in the motherboard too and new thermal paste in the "amstrad cooler".  8)

Excellent community here.  :D

a7mag3ddon

Are you UK? I can tell you where to buy retrobrite off the shelf cheap as chips.

G40rocket

Quote from: a7mag3ddon on 14:56, 08 May 15
Are you UK? I can tell you where to buy retrobrite off the shelf cheap as chips.

Nope, i'm from Portugal.

"Retrobright" product here is very cheap too, normally a small bottle (100 ml) cost me around 1,80 euro.

There are in more ammount but this is enough for the keyboard.

Thanks anyway. ;)

seanb

Quote from: a7mag3ddon on 14:56, 08 May 15
Are you UK? I can tell you where to buy retrobrite off the shelf cheap as chips.

You could tell me.
I promise I won't tell anyone
Thou shall not question Captain Wrong!

a7mag3ddon

LoL. Sure. Superdrug : Jerome Russell Bblonde 40 vol 12% peroxide. £1.69 for 75ml. Or Morrison's £1.89.

Use exact same as retrobrite.


Powered by SMFPacks Menu Editor Mod