Help me understand this simple circuit (modding Philips CDi console)

[hestermofet]

I have no background in digital or analog circuits, but I am handy with a soldering iron. I have a Philips CDi 210/40, and apparently, it's relatively straightforward to mod these to output NTSC instead of PAL. This webpage explains what to do, based on the service manual:
https://www.cdiemu.org/?body=hw/cdi210swFor some reason, this webpage shows how to do all the wiring, but not what to connect the wires to.

I don't know if I understand the principle here very well, so I wanted to confirm: I essentially need to bridge contact point 3203 to the contact point for +5V, correct? With a 10K Ohm resistor, apparently. This doc also has a bit more info (for example, which resistor to use). My model uses the Mono III mainboard, so check that section.
https://retrostuff.org/2020/01/12/modifications-for-philips-cd-i-players/
I could use a three pole switch if I want to switch between PAL and NTSC, but I don't need that functionality. According to this doc (for a different model of CDi):
https://retrostuff.org/2013/08/17/60-hz-modification-tutorial-for-philips-cd-i-player-cdi-220/

 

[AmigaPhreak]

Yes, it looks like you just need to move the resistor from the PAL location to the NTSC location.

I'm looking at this picture: https://retrostuff.org/wp-content/uploads/2022/01/monoiii_50-60.jpg

You say you are handy with a soldering iron...consider that SMT parts are difficult to solder and require special tools. Unless you worked (or do work) as some kind of electronics technician (which is about the only scenario I can imagine having the necessary physical skills/tools, but not have an understanding of electronic circuitry), you might not be as sufficiently handy.

 

[Xenocrates]

Might be easy enough with hot tweezers, and minimize the chances of a hot air station causing other issues.

 

[hestermofet]

Yes, it looks like you just need to move the resistor from the PAL location to the NTSC location.

I'm looking at this picture: https://retrostuff.org/wp-content/uploads/2022/01/monoiii_50-60.jpg

Thanks for that. I see some people are using a switch. Does that mean removing the resistor, soldering wires to the pad, and then putting a through-hole resistor in line would work? I haven't actually removed the CD drive and Digital Video Cartridge, and those are obstructing the mainboard, so I can't actually inspect it myself to see if I could pull that off. Removing an SMD component and putting a wire on the pad would be a lot easier for me than removing the component, then relocating it.

You say you are handy with a soldering iron...consider that SMT parts are difficult to solder and require special tools. Unless you worked (or do work) as some kind of electronics technician (which is about the only scenario I can imagine having the necessary physical skills/tools, but not have an understanding of electronic circuitry), you might not be as sufficiently handy.

Good question, and you guessed right. I've had several careers in the past, and one was as a technician who repaired small electronics. I had my own business repairing laptops, smartphones, and other small electronics, and was eventually employed as a service technician for repairing and refurbishing pagers (of all things). Eventually, I started taking a medication that causes hand tremors, so I went back to school and am now a software developer. When I retire, I plan to go back to school again and get a degree in either electrical or computer engineering, since post-secondary education is free for people who are older than 65 where I live. For now, I just like working with my hands, so make simple electronic doodads using Arduinos and Pis based on the designs of others, or enjoy refurbishing/modding retro consoles. The last SMD device I worked on installing a Optical Disc Emulator on a NeoGeo CD, which requires lifting a pin on a microcontroller so that you can solder one wire to the leg and another to the pad underneath. Relatively delicate, but I can't do anything finer than that.

Might be easy enough with hot tweezers, and minimize the chances of a hot air station causing other issues.

Not a bad idea. Would be easier if I hit it with some flux first.

I'm weighing my confidence to do this job versus potentially damaging a relatively rare piece of history. The alternative is to use one of those readily available PAL to NTSC converters you can find all over the Internet. I'm using a small 11" LCD display I have that accepts both PAL and NTSC composite at the moment, but I'd really rather use my Trintron. Might be worth investing in a generic PAL conversion device in case I end up collecting other Euro-centric consoles.

I used to have this gorgeous Toshiba 32" CRT that accepted component, and displayed PAL, NTSC, and SECAM, but man, was it huge, so I sadly had to get rid of it. I think it was a TV meant for the Russian market at the tail end of the Soviet Union, which is why it accepted so many broadcast TV standards.

 

[Mark086]

The pins are being pulled high by the resistor, basically setting a pin to a 1. Likely the pins have an internal pull to ground of a much higher resistance.

You could use a jumper or a switch in the circuit to make it set-able, choosing which pin is held high, thereby identifying which type of video output is desired.