Faulty OSSC v1.5

[Velocity]

Hi Guys,
I just picked up a faulty OSSC and I’m hoping it will be an easy fix!
So the device turns on ok and appears to boot to the test pattern, however the image on the display is a little bit distorted.
This is the same issue the previous person said they had, taking a look at the board it’s not a DIY kit, and it doesn’t appear as though anyone has ever tried to fix/modify the unit in anyway.
I’ve included an image of the display, if you need to see images of anything else just let me know.
Thanks,
Vel

[Morpheus_79]

Did you test any of the inputs(?)… just to see if it results in the same faulty output?

Just off the cuff, i would say: since afaik the A/D converter (TVP7002) isn’t involved in creating the test pattern, the problem is related to the FPGA or the HDMI transmitter IC. The best case scenario is a simple solder bridge or a cold solder joint on the FGPA, the HDMI transmitter IC or simply the HDMI out connector. Worst case: one of the two ICs is broken and needs to be replaced.

[Velocity]

Hi Morpheus,

From what the seller told me, the unit was working previously, so I don’t think is related to a solder bridge.

Also, would it be possible to have a cold solder joint occur after the initial soldering was carried out?

The only console I had to hand was my original Xbox with component cables, so I tried them in AV2 and the unit appeared to recognise the device (the LCD changed) and it did eventually display the picture from the Xbox on the screen, however it looked awful as the test pattern does.

The seller also included a DVI to HDMI adapter, but I used one I already have as well which I know to be working, so at least we can rule out a simple cable issue.

Is there a simple way to test the three things you mentioned without switching out the components? So I only have to potentially replace the one thing that is at fault.

Thanks,
Vel

[Anonymous]

Also, would it be possible to have a cold solder joint occur after the initial soldering was carried out?

That is the definition of a cold solder joint.

Is there a simple way to test the three things you mentioned without switching out the components? So I only have to potentially replace the one thing that is at fault.

The simplest way is visual inspection, and hopefully you find some faulty joints, or some other visual indication of where the problem lies.

[BuckoA51]

Looks like ESD damage to me though that’s just a wild guess. You can check for that by getting a multi-meter, select diode tester function then connect the positive probe to DVI connector and then test Data Link1 and digital clock pins one by one with the negative probe. They should all measure around 500-600mV if there is no damage (see https://commons.wikimedia.org/wiki/File:DVI_pinout.png).

[Velocity]

I have a multimeter, so I’ll check that tomorrow and report back, thanks!

[Velocity]

So, I just got out my multi-meter and read your question again and realised I wasn’t quite sure on what some of that meant.

So I thought it would be best to double check before I make the situation worse!

With the positive probe when you say the DVI connector, do you mean the outer casing of the connector or to the relevant pin inside the connector itself based on the pinout image you linked to?

With the negative, do use it on the points on the bottom of the OSSC, or do I use it on the pins inside the DVI connector?

Apologies if this seems like a daft question, this is my first time using a multi-meter!

[BuckoA51]

Touch the positive probe to DVI connector chassis and the negative to the relevant holes on the DVI connector.

[Author]

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