[SOLVED] RGB LED CD activity mod

[New Nova]

Hello there,

My PS1 is a SCPH-1002 PU-8 board chipped. I modded the LED with an RGB one, with 3 legs on it. For now, it is only red color since the last leg is not connected to anything. I want to know where I can solder the third led to have a CD activity thing. Like when the disc is accessed, the LED changes color. Any help on where I can solder that ?

Thanks !

EDIT : My LED was common anode, which means "+" polarity on the middle leg. I solved this by :
- wiring anode to the "+" of the power LED
- wiring blue cathode to the "-" of the power LED
- wiring red cathode to pin 7 of the MM3 chip

Here ya go

[leafy]

That is a great idea! I would guess you could probe the signals on the laser ribbon connector, and find the one that seems to correspond with CD activity. Meaning, laser reading data, I assume? I would think by now someone should know which pin, but I can't seem to find any exact reference for that board.

Then, I assume you could just wire in the appropriate resistor to a another leg of the LED.

The color mix would look cool!

Some of the mod chips have a pin for optional LED activity indication. You could hook the 3rd LED to that, I'd bet. With current limiting resistor of course.

[New Nova]

I don't think you need any resistor for that, just put the 3rd LED leg and it's done, I've seen a video doing it, but not on my model.

[leafy]

Got it. I didn't know the voltage output, so I always say that just in case for LED. Yes, typically for most LEDs if the voltage is 3 volts or less no resistor is needed.

I forgot to ask, is the LED common anode or common cathode? I guess common cathode if you want the PU-20 to source the LED voltage for CD activity, correct?

MM3 chip pin 2 is for optional LED

[New Nova]

Oh sorry, it is not an rgb led, it is bicolor (RED/BLUE for me it seems).
Something like this https://www.iascaled.com/blog/driving-3 ... h-mrservo/
For the video it is this at 19:25 https://www.youtube.com/watch?v=hT5NSWS-znc

If I solder the last pin of the LED on pin 2 of MM3, will it work ?

EDIT : Middle one is common anode it seems. Common ground if you want.

[leafy]

Oh, ok, only 2 colors. Common cathode would be the middle pin is connected to ground, and the other 2 pins for the LEDs, need a voltage source. Common anode would be the middle pin is connected to a something that sources the voltage needed to light the LED, but they are turned on and off by sending the 2 other pins low for each LED. In that case, you need enough ground to sink the current, grounding the LED, and thus turning it on. You should have access to some type of data sheet for the LED, and that should give you your voltage drops.

I'm not sure what voltage pin 2 of MM3 sends out, but you could test it. I'm not sure if it would work directly. I have seen an older diagram that uses VCC and a resistor to an LED connected between pin 2 and VCC. So, you may need to use VCC. I have been wondering this myself.

Example of possible wiring in attached. It is from old MM2, but I would think the MM3 the same. The diagrams only cover 550x-900x to add an LED, so it may not work on 100x.

I love this guide about LEDs: https://learn.sparkfun.com/tutorials/li ... iodes-leds

[New Nova]

Ok thanks but know I have problems with the cd unit. No power comes from it and the motor doesn't spin at all.

[New Nova]

I solved my problem lol.

[New Nova]

And for the voltage drop, I don't have ANYTHING about the led, that's an led that I salvaged from an old pc mouse. How can I "sink" the current ?

[leafy]

Real quick, I just want to point out, that looking at that diagram I posted, you would use that wiring with a common anode LED, and give the common anode the PSX 3 volt source like (like the pin 1 of the MM3 chip), then the cathode of the LED you want to turn on would be wired to pin 2 of the mod chip with the resistor.

Oh no! Laser issue! What model PSX, board, and laser are you using?

There are some fuses to check for no spin. Did you do something to the unit to cause it or...?

From an old repair guide, tiny fuses on board:

The following faults are apparent when these fuses 'blow':
A. (ps604) 2.3 amp, blank screen, no laser spin.
B. (ps605) 0.7 amp, no joy pad operation.
C. (ps603) 1 amp, no pic's - snowy raster, and no laser spin.
D. (ps601) 1 amp, pic's but no laser spin. hence no game boot, just goes to audio menu.
E. (ps602) 1 amp, will not affect game playing if this fuse pops, it is designed

[New Nova]

No, for the cd unit it is ok, I just didn't push the lid button, I'm a fagot I know.

[New Nova]

My led has the "+" on the middle leg. The other 2 are probably "-". This is a red/blue led. I tried your thing and it didn't work. The red is wired at the place of the power LED.

What can I do now ?

[New Nova]

Solved. Soldered the last wire on pin 7, and the LED work. I don't have a screen available for know for being SURE that it works, but the cd spins, and seems to play.

[leafy]

Solved. Soldered the last wire on pin 7, and the LED work. I don't have a screen available for know for being SURE that it works, but the cd spins, and seems to play.

Oops, you forgot the door switch. :laughing

I'm glad you got it all working.

Right, the middle leg is the shared pin for those LEDs with more than one color. But, assuming your plus means it is the common anode type, then you would just wire the red cathode to pin 2 on the MM3 chip (if pin 2 really is the LED out).

The diagram I shared would only work for the other way around, the common cathode.

I shouldn't have given you so much information at first maybe about the LEDs and all of that.

Oh, I saw your edit just now of this post. It is more clear to me now what you did.

I guess the pin 7 is the CD door input.

I found this information:
These are the pin functions of the MM3:

1. VCC
2. An optional activity LED output.
3. Used to support stealth mode for anti modchip games.
4. Reset button input.
5. GATE/WFCK
6. Data output to send the correct copy protection serial message so the console accepts the disc.
7. CD door input.
8. GND

[New Nova]

So I tested the mod with a screen to see if the game boots, and yes, it does. And when the CD is accessed, the LED changes color. So absolutely working.

[leafy]

So I tested the mod with a screen to see if the game boots, and yes, it does. And when the CD is accessed, the LED changes color. So absolutely working.

Great! I just tested my MM3 and, no, there is nothing going on with pin 2. So the MM3 binaries floating around are either a different build or MM3 never had it and it ended with MM2.

Pin 6 is where the SCEx codes are sent out. I tried an LED pin 6 to frame ground and that works fine.

Are you sure your LED isn't on pin 6? You said 7, but I thought that only changed when you open the door. I didn't see it change when I metered it.

pins of the PIC12C508

PIC12FC508.jpg

Wired up a demo to see what's up -

20200909_202150s.jpg

[New Nova]

Yes that's the 7. I didn't make the MM3, I bought it from ebay, so maybe there's different things. The most important thing is that it's working now.

[Administrator]

Rather off connecting it to the interrupt pin on the CXD-1815 instead. You'll have better results that way since all CD-ROM data is triggered by an interrupt.

[leafy]

Oh! Someone knows what the signals are on the pins! That does sound like a better signal to use.

There was a video where a guy just attached a leg of an RGB LED to one of the motor lines for the CD. It looked like CN701-1 for the sled movement. Certainly not an indicator of CD activity so much as a way to generate a blinky effect.