Adding 50/60hz Output on Chinese SCART to HDMI Adapters

UPDATE 2021-01-02 – I’ve created a repo with the datasheet for the main encoder (and other MStar chips) at https://blog.obsoletemadness.com/2021/01/02/mstar-datasheets/ 

I recently purchased a couple of cheap SCART to HDMI adapters from AliExpress. The first one I ordered claimed it could do both 50 and 60hz output. Unfortunately, it didn’t have a button to do the toggle and after a prolonged fight with the vendor I got a refund.

scart-to-hdmi
The first board which claimed 50hz output.

So I tried a different model. This one clearly had a PAL/NTSC button on it. (As an aside, while today the price difference between the two models is about $1, when I originally ordered these, the second one was almost $20 dearer).

scart-to-hdmi-2
Second attempt – this one has the PAL/NTSC toggle button.

Sadly, while this one could output 720/1080p@50hz it would corrupt the display after 30 seconds. Rather than be stuck with two adapters that didn’t work the way I needed, I decided to see if I could add a PAL/NTSC button to the one that did work!

Looking at the two devices it was clear that one was simply a cost reduced version of the other (at the time I bought them, there was nearly a $20 difference, it looks like they’ve come down a bit since).

board-1-cropped
Board with PAL/NTSC toggle. Board is labeled “SCART+HD2 HDMI 2014/12/23” SW2 is the NTSC/PALN toggle. Note the additional HDMI in jack and Coax (audio) out. 
board-2-cropped
Second board sans PAL/NTSC toggle. Board is marked “SHD1000 V1”. It’s essentially a cost reduced version, with the exact same (unknown) chips.

So, I traced where SW2 on my broken board. SW2 goes directly to whatever pin this is on this unknown chip.

pull-to-ground

scart-mod-adding-a-button

The way I did this was to wire one end of a switch to the unpopulated R103 pad closest to U14. I then wired the other end of the switch to ground via a 470 ohm resistor.

scart-wire-in-place
All together now – sorry for the potato quality.

Finally I drilled a 6.5mm hole in the front SCART connector face of the case and pushed the switch through.

scart-back-together

Behold! 50hz output!

50hz-output
50hz Glory over HDMI

Is this worth it? Only if you already have the adapter without the PAL/NTSC toggle. If you’re buying one  the price difference between the two devices is only $1 now – and the one with the toggle has HDMI input, and Coax digital out.

A quick review

These boards do what they promise, they convert SCART (including RGB) to HDMI at various output resolutions. The video quality on them is quite good – and they’ve worked with everything I’ve tried (C64, Amiga RGB, Sega Megadrive, SNES). The usual caveats apply for progressive 240p-ish sources. There is a de-interlacing filter on them that bobs the image slightly.

Future Mods

I need to find out what the two unknown chips are on the board (U11 and U14). U14 is clearly a micro of some description, handling the button presses, etc. U11 looks like an LCD TV SoC (which makes sense). But what one? The headers for what I think is the ISP are quite clear – so perhaps there’s an opportunity to (say) disable the de-interlacing.

39 thoughts on “Adding 50/60hz Output on Chinese SCART to HDMI Adapters

  1. Do you know if there is a way to influence the output aspect ratio in these? Currently they seem to stretch the 4:3 input to something that looks 16:9, but off-center and with some black bars. I would like to control it.

    • Nope I don’t sorry. If I had the tools I’d try and dump the program of the little micro on the board. I haven’t found a datasheet on the main chip though so not sure how useful it would be anyway.

  2. I have a SHD1000 V1 just like what you’re working on. I loved it for the two times it worked but now I no longer get any signal from it. It turns on and my tv acts like it sees signal but nothing is there. Do you have any information on how I can troubleshoot what may have failed? As far as I can tell, everything on the board looks clean and in normal condition.

    • Not really sorry. I find they run hot (especially the main ic and HDMI transmitter) and don’t usually come with any heatsinking. As such I’ve got one that cooked itself. If you order another grab some cheap heatsinks to go with it.

  3. Hello, I have one same of you. The problem is the image is shift to right of screen. Please , you can dump the CI u100 ( spi 4mb) and share for test? thank you.

    • I don’t have the tools to do that…unless you can point me to an Arduino project or the like to dump the contents?

      • Good Morning.
        To dump the spi I used the ft232 and mstar spitool and connected it to the J5 of the scart board. Stm8s003 has no way to dump eeprom as it is read protected.
        I tried to read it and ended up erasing his memory and the scart doesn’t care anymore.
        I need the copy of the SPI J5 from the smaller scart. If u can help I appreciate it.

  4. I’ve got a later revision of the model with the SPDIF out and the markings on the chips haven’t been etched off, so I thought I’d post them here (I know most have been posted, I’m just being thorough):

    Main encoder IC: MST6M182XST-Z1 (MStar)
    HDMI transmitter: SIL9022ACNU (Lattice)
    U14 (MCU): STM8S003F3 (STMicroelectronics)
    U100 (SPI flash): 25Q32JVSIQ (Winbond)

  5. Btw, I just ordered one of these (the one with HDMI in), and it works… except with the HDMI USB capture device I also got… I thought it didn’t work, but it does with another source. Very useful.

    I thought it could be some hotplug detect issue but the Sil9022 output driver should detect it as low as 1.9V, and it’s around 3V…

  6. For the record, I managed to get it to work by forcing the hotplug detect signal internally…
    I also modded it to force RGB input to save one power brick. I tried to force 4:3 as well but it doesn’t work. I’m quite sure I’ve seen it handle it once or twice before, maybe I burnt the input pin or something, now it has like 3.3V regardless if there’s anything on it…

    • (4:3 is supposedly detected when pin8 on SCART is >9V, and here there’s a resustor divisor (10k and 2.2k) which should get about 2V on pin 141 if I didn’t misscount.)

    • The unpopulated header next to it seems to be: GND, SWIM debug, NRST (reset) and 3.3V.
      And the other header that goes to the main chip seems to be a USB interface, but probably host, plugging into a computer doesn’t do anything.

      • I’m not sure it’s USB. There’s a heap of Mstar programmers on AliExpress and a few flashing tools floating around online. I’ll need to check the spec sheet to see what protocol it uses.

  7. I accidentally connected 12v. Fried a transistor near the power connector. Would you be able to tell which traffic is marked as U3?

    • U3: M3406-ADJ
      I repaired the 0.6 volt power supply after I connected 12 volts. Replaced U3.
      But MST6M182XST-Z1 is no longer active.
      Only STM8S003F3 works, even downloaded the firmware.

  8. I made a mistake.
    After U3, the voltage is 1.3v. I just have a resistor R16(40.2kOm) in the open.
    0.6*(1+(47k/40.2k)) = 1.3V

    Fixed and earned 25Q32JVSIQ, MST6M182XST but SIL9022ACNU does not work, it needs to be changed.

    • I have programed the stm8s to slave address 20, inserted EDID e scart bootup and enter in BUG after 10 minutes. I believe the driver register for SIL9022ACNU is needed in code. I working on Stm8s glitch do bypass R.O.P in stm8s and dump the full code.

  9. I upload dump in github_com/OlegDX/SCART_HD_HDMI.
    And also disassembled the firmware , everything was written as before

    • I have dumped my EDID and eeprom in data logger, The EDID is the same as your dump the eeprom not. I try to edit yout dump with my eeprom and not boot up the crc of eeprom is FE.

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