Gameplay slowdown on Coolbaby RS-37 famiclone

[famulator76]

I recently picked up the RS-37 famiclone from Aliexpress. I noticed that all my famicom carts run a slightly slower speed than they should. The slowdown is so slight that a non-gamer might not even notice. I find the system unusable. I'm not sure whether to chalk this up to "you get what you pay for". FWIW, I'm using the system with a NTSC TV.

Has anyone else experienced this issue?

[FAMICOM_87]

The system is PAL.

[famulator76]

I see. That the system is PAL wasn't on the Aliexpress listing. Are all the Coolbaby RS-x family designed for PAL TVs?

[FAMICOM_87]

Are all the Coolbaby RS-x family designed for PAL TVs?

Not all, my cool baby RS 36 mini is in NTSC mode. You can replace the criystal form 26.x MHz for PAL mode to 21.x MHz for NTSC mode. And short some pads to switch the mode

[famulator76]

famicom_87,

I appreciate the info. I don't see a lot of this forum or nesdev.com on the specifics of the crystal swap. I came across a few links that seem to apply to full hardware clones rather than NOAC. Can you comment further on what needs to be done in addition to the crystal swap?

[FAMICOM_87]

Some quality pictures from the both sides of the PCB will help so give us some

[famulator76]

I attached pictures of the RS-37.

[FAMICOM_87]

I do not see any pads, I can not see becouse of the slot. Are they any above the glop-top?

[famulator76]

Here is a close-up of the PCB area around the blob.

You cannot see attachments on this board.

[FAMICOM_87]

cool ,man you hava a luck I made very similar NOAC to NTSC as well. Here are my pictures and video before the change https://www.youtube.com/watch?v=KxY-IGJjv40
So you have to change the crystal and connect all that pads together. If you wish see the documentation for this NOAC in the description under my video

[famulator76]

famicom_87,

Cool. I watched your video, looked at your pictures and read the VT02 documents you linked. In the data sheet, I that the XPORN, XF5OR6 pins on the IC control the TV mode. If I am interpreting the VT02 application note document correctly, it instructs the reader to short J1 and J2. I don't see a J1 or J2 on my PCB or in your pictures. What pads do I need to connect?

[FAMICOM_87]

like you I was confuset at first for the same reason not finding J1 and J2 on the PCB according to the schematics, but I tracked the traces from corresponding pins from a NOAC ,my IC is SMD as you can see. So the pads are those on your last 2 photos above the glob-top on the left , short them all (you will find that 2 of them are together any way)

[famulator76]

famicom_87,

Thanks for all the help. I assume you mean the pads labeled R4 and R5. I will short them after replacing the crystal.

[FAMICOM_87]

famicom_87,

Thanks for all the help. I assume you mean the pads labeled R4 and R5. I will short them after replacing the crystal.

Yes

[famulator76]

I swapped the xtal and soldered all four pads at R4/R5 together. The ribbon cable that connects the audio/video/power PCB to the main PCB was damaged so I had to make new connections. Currently the power LED lights up so the power seems good. I'm not getting any audio or video though. If anyone has troubleshooting tips, please share.