D5 (SD05-7) is rated for a working voltage of 5V:

https://mou.sr/46aulmu

… so the 9V most definitely killed it. Your OSSC should work fine without it… but i would recommend…Read more

I think my multimeter can measure Hz (I don’t know to which extent, and if it can help)

It’s an 27Mhz oscillator. While your multimeter may have some oscilloscope features, it’s mostly rudimentary and limited to a kHz range.

Do you have an idea how much it will cost ?

Sadly i don’t know. The repair may be cheap in replacement parts… but the f…Read more

A partially broken U1 would explain the “NO…Read more

That’s one of the great things with the OSSC: its good repairability!

is it expected for the firmware to not print anything on the LCD?

The firmware is able to print out “init error” messages on the LCD if some of the ICs are not responding:

OSSC Init Error -2. Need replacement

But only if they are not responding. An IC causing a short on one of the power rails may…Read more

I don’t know how to tell if I have the reference design or a clone.

That’s not the eference design. U5 is rotated and it uses a different display with a flat flex cable connection, while the reference design uses this vertically mounted New Haven Display:

How can that be if you say U6 powers it?

I said: U5 powers it!

how about I connect the o…

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u5  3.3V       # the ground pin is not the middle one like you said here

In the reference design it is! You can see it here – in the 3D rendering of the KiCAD file:

The middle pin is definitely connected to the ground plane.

BUT i’ve seen some modified PCB designs where other voltage regulators are used, which may have a very different pino…Read more

… and costs around 5 bucks. If you don’t know how to replace it yourself, you can try to give it to someone who does (a friend or a repair shop).

As ‘marqs’ said: there could be something else broken… but it’s a good starting…Read more

Since the OSSC Pro is a scaler it has way better compatibility with TVs (resolution wise). It also should be more stable with the more “exotic” outputs of some retro gaming consoles and it comes with…Read more

Which board revision of the OSSC do you have (1.8 or older)? If it’s an older revision than 1.8: is it modded for the use of the v1.xx firmwares as described here(?):

OSSC v1.xx series beta firmware

According to @marqs :

To program flash, a combined FPGA image must be first generated and converted into JTAG indirect Configuration file (.jic). Open conversion tool (“File->Convert Programming Files”) in Quartus, click “Open Conversion Setup Data”, select “ossc_pro.cof” and press Generate. Then open Programmer and ensure that…

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https://www.macnica.co.jp/en/business/semiconductor/support/faqs/intel/124561/

… go in Quartus Prime to “Tools” -> “Options” and select this option under “Programmer”:

OSSC Pro: Failed Firmware Update

… there are some problems with the very cheap ones. But for just a one-off usage it’s understandable, that no one wants to spend around $300 for an original Altera/Intel Blaster or even $70 for a Terasic one.

I would recommend buying…Read more

I’ve ordered a USB blaster and I’ll try reflashing the firmware via the JTAG port. If that fails I’ll send off an e-mail. Thanks!

Please be aware, that (aside from the very expensive original Intel/Altera USB blaster) a lot of cheap USB blaster clones are out there. Some work better than others – depending on the combination of driver versi…Read more

Shall I check if the oscillator outputs the required frequency?

Yes.

The ‘display flashes + solid green led’ behaviour is somewhat similar to an OSSC without any firmware flashed onto it. I’ve seen similar behaviour on an OSSC with esd damaged flash memory… but since the op had nearly the same problem as you and fixed it by replacing the…Read more

But the assumption in this case is NOT: the oscillator is broken. It’s more or less: the FPGA doesn’t do anything – why is that? Could be a broken FPGA, or a broken oscillator,  or a broken flash, or a broken something else. Sometimes things simply break…Read more

… and some purple and green noise and lines in the test screen:

In that case there were some contact problems inside the HDMI port. So maybe there are some dirty pins inside the port… or there are some cold/broken solder joints between the…Read more

it looks that the wire that connects to the chip leg actually is the leg that connects to ground?

No. Originally the leg isn’t connected to anything:

Does that mean the OSSC is malfunctioning?

Yes.

What is “THS7353 video amplifier”??

I don’t know how similar the the Kaico version to the original PCB design compares… but on the original the THS7353 (U17) can be found here:

It’s a pretty cheap component:

https://mou.sr/3M74dPQ

… and (with a bit of experience) not that hard to replace usi…Read more

But why not use a separate y-cable or a cable/input switch on the pc speakers?

There are some “ancient” DIY USB-Blaster projects out there in the wild… like this Japanese one from 2009:

https://translate.google.com/translate?sl=ja&tl=en&u=http://sa89a.net/mp.cgi/ele/ub.htm

… or this one (based on the Japanese one) from…Read more

Was it this project? https://hackaday.io/project/194894-usbblaster-based-on-ch552g

Yes… exactly this one. It is a fun project… but because of its closed source firmware its timing issues can’t be fixed. At leastDoug Brown fixed them for other commonly available CH552G-based USB-Blasters – like this…Read more

But: you are right. It’s a problem related to all 3rd party USB-Blasters. They all have some kind of timing issue. Most of the very cheap ones for around 5 bucks (if they work at all) work better under Linux and badly…Read more

https://www.mouser.fi/ProductDetail/870-IS25LP016DJBLETR

There’s a fair to good chance it’ll fix the problem. But sadly there’s no guarantee no other IC is damaged.

https://www.aliexpress.us/item/3256805938471895.html

… which will work perfectly fine with a custom firmware:

https://github.com/dougg3/CH55x-USB-Blaster/

… flashed onto it… liked described…Read more

Your described behaviour (blank LCD with backlight on and no output) is the standard behaviour for a OSSC with no firmware. So maybe(!) your FPGA(??) or the flash memory was…Read more

https://junkerhq.net/xrgb/index.php?title=OSSC#AV1_audio

AV1 audio
Analog audio from SCART input is bypassed to a 3.5mm stereo output jack next to video output connector. On v1.6-> boards the jack alternatively functions as AV2 audio input, selectable via a miniature switch.

So: did you set the miniature switch from…Read more

What cable you used (looks like a enameled one)?

It is enameled… but i don’t know the wire gauge. It’s probably AWG 30 or 31!? I don’t know for sure, because those are wire scraps from my former job, where colleagues used these kind of wires to manually wiring the components of in-ear hearing aids to each other.

https://circuit-board.de/forum/index.php/Thread/20199-SNES-RGB-Bypass-f%C3%BCr-PAL-3-Chip-SNES-SNSP-CPU-01-02/

Even though it’s a German forum, they don’t mind if you ask in English.

the images of the amazing soldering job by @morpheus_79 doesn’t show the pin 126 lifted, and why he (re)connected the pin 127 to ground?

Because i (wrongfully) cut the trace to ground from the pad for pin 127 (there was a fault in the schematics which is now corrected). So i had to reconnect the pin with the ground plane (i’m not THAT happy wit…Read more

https://github.com/marqs85/ossc_pcb/assembly/assembly_tips.txt at

Before turning on power (DC 5V / center positive / min. 1A supply), it’s a good idea to check that power supply lines are not shorted…

Read more

It is needed by the red LED. So you only have to keep it, if you are planning on restoring the functionality of the red LED… either by reverting back to any pre 1.xx firmware, or by keeping the 1.xx firmware and doing a more difficult…Read more

It is possible to rewire the v1.6 pcb revision…Read more

<p style=”text-align: left;”>I tried the mod on the first page, but it is giving me an error.</p>

Your OSSC gives you an error? What does the error message say?

Is there any way around this?

The 1.xx NEEDS the hardware modification. So: no.

 It is version 1.6. The problem is that pin 25 is grounded.

Are you sure it’s grounded? The schematics for v1.6 don’t show a connection to anything at all for pin 25:

I’ll check the suppliers you recommended, order everything (with a few extra spare AMS117), and let you know of my results.

Pay attention to buy a version of the AMS1117 which outputs fixed 3.3V (since there are also versions available for other fixed voltage outputs, like 1.8V… and a version with an adjustable output too -> which all won’t w…Read more

Maybe they changed the U5 for costs reasons or because it would no longer be produced in a near future ?

It’s still available and will be produced in the near future. But it’s…Read more