HDMI perfectly working but anlog signal is distorted

Sk8er000

New member
Hello,
I've recently installed my Ps1Digital, updated to the last firmware, set the resolution to 1080p and run some tests.
Launching a FMV and going into the INFO/TEST section it gives me "all hearts":
PHOTO

I've played with console for about an hour and didn't notice any issue (usigng both PSIO and X-station).
For the last test I've connected an analog cable (tried both composite and RGB) and noticed that I have a very ditorted signal on the analog side while the digital one is perfect (before the installation it was working):
PHOTO


Before turning on the first time after the installation I've checked all the connections with my scope and multimeter, here are some photos of my installation of the GPU flex:
PHOTO
PHOTO
PHOTO


Does anyoune have any suggestions or ideas?

Thank you in advance
 

Sk8er000

New member
I did further test..
From the previous image is not very clear but the distorted analog signal it's not like a constant sync loss, the colors are right and the sync is present but the image is very shaky (horizontally) wtih horizontal lines, while the digital signal is perfect.
Following the service manual I saw that the circuit is the following:
PU18.jpgIMG_20201122_110248_032.jpg

So I've tried:
To reflow IC202 out side, IC203 and the analog AV port.
On the GPU side I retuched Hsync, Vsync, CLK and PCK.
I swapped the original PSU (recapped wid low ESR capacitors), with an original one with stock capacitors.
Tried to gently move the GPU flex while the console is on.
Tried to remove the wifi antenna

Nothing of this changed anythig though :(. Any ideas @citrus3000psi @chriz2600?


This is a better photo to understand the distortion (the photo is with a shielded RGB cable on a bvm 20f1):
IMG_20201122_122050_271.jpg
 
Last edited:

citrus3000psi

Administrator
Staff member
The PS1D doesn't interfere with the analog, so I'm inclined to think its something farther down the chain. Can you try composite video on a standard consumer tv set.

Also what is the history on this console? Did you just get it?
 

Sk8er000

New member
I was using mainly a composite cable on a crt to make tests.
The console was bought used for this task and had the PSU broken (for that reason was very cheap) but after a full recap I let it run with PSIO for a couple of hours, I did the same thing when I've installed the X-station (I had to find some alternate point for the I/O board) and never had problems to the analog out.

The very strange thing is that from the digital side of the ps1digital everything was always fine since the first try.

Anyway after a lot of hours spent troubleshhoting maybe I found out the possible cause of the issue and maybe fixed it...

For soldering the flex cables I used my usual flux that is a flux pen from Chip Quick.
Despite having some good and shiny solder joints on the flex cables it created some very small shpere of solder and brought them under the GPU flex cable (I noticed them ony with the microscope).
Those little spheres weren't enough big to short anything (chacked multiple times with the multimeter and microscope) but probably were acting like a sort of antenna in some traces.
Trying to get them off lifting the GPU flex cable without removing it was a real pain.
Initially after cleaning the board when I turned it on everything was working fine but everytime after some minutes (maybe due to the rising temperature on the console the solder residue expanded) the interference gradually reappeared.
After a lot and a lot of tries now after leaving the console turned ON for a couple of hours in the xstation menu the interferences didn't come back.
Next test will be playing some games to see if an higher temperature can make some difference (I hope not).

I still can't figure how this was possible..
 
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