This mod will tell you how (assuming you have some decent solderingskills) to add a vga port to the back of your Dreamcast, forconsiderably less than the cost of a commercial VGA box which does the exact same thing. No IC's are involved here, just regular components,like capacitors, resistors and diodes. I plugged my Dreamcast into myLCD monitor, and it works like a charm.
Tools Needed:- No. 2 Phillips screwdriver
Wire cutters/strippers
Soldering iron
Dremel + cutting bit (steel bur or cutting wheel works well)
Materials Needed:- 3x 220uF capacitors
2x Silicon diodes
2x 4.7Kohm resistors
2x 150ohm resistors
1x Slide or toggle switch
1x Female VGA port
1x 3.5mm stereo audio jack
Solder
Electrical tape
Step 1:Remove the four screws on the underside of the dreamcast. There will beone in each corner. If you have a modem for your Dreamcast, remove itto expose the 4th screw.
Flip the whole thing right-side up and take off the top panel. Makesure you didn't leave a disc in the drive.
Step 2:To remove the GD-ROM Drive, remove the screws holding the metal assembly to the other metal chassis.The whole GD-ROM drive assembly lifts out, metal chassis and everything.Don't lift out only the plastic part, take the whole thing.
Step 3:To remove the PSU, remove the screws that hold the power supply in place. Unplug that white connector that connects up to the power switch. After that, pullthe power supply straight up off the chassis. The power supply justclamps itself onto 6 thick wire terminals, so you don't want to put anyundue stress on either part.
Step 4:To remove the mobo sheild, remove the ribbon cable from the controller plug connector board to themotherboard. Do yourself a favour and remove the fan power cable. Remove the four screwsthat hold the board in place, but don't try to remove the board justyet. Remove the screws which secure the metal shield in place, and liftit off, enabling you to remove the connector board. You'll have toremove the plastic bezel as well.
Step 5:Now it's time to remove the motherboard, if there are any screws at this point, remove them. You'll have a mucheasier time if you lift it from the front of the board, as shown in thephoto. In this picture, you can see the power connector I was talkingabout earlier, in the upper right-hand corner of the board. Don't worryabout the rubber heatsinks on those two square chips, the heat-pastewill keep it adhered adequately onto the chip. If it does come off,just put it aside until you're ready to put the Dreamcast back together.The heatsink is important. Your Dreamcast won't last more than about 10seconds without crashing if it's missing (first-hand experience).
Step 6:
The circuit we're going to use is made of reasonably standardcomponents, so you should have no problem getting what you need fromyour local electronics supplier. You could probably get this stuff at the CrapShack, but you may havetrouble finding 150ohm resistors. Everything else will be there, but will be overpriced.
Anyway, as for the capacitors, the negative side should go towards theVGA connector. All of the pins on the VGA connector marked with a blackdot must be grounded. The ones with white dots are unused.
By the way, if you want to add an audio jack, just use pins 2 and 3and wire that to the right and left terminals on the jack. Ground theground pin on the jack. I can't tell you, by the way, which one's leftand which one's right, so you have a 50/50 chance of getting it right.My stereo's messed, so I can't tell you whether I picked the right one.
Do yourself a favour and don't try to solder on the top of the board.Flip it over, and you'll see some solder dots that are spaced furtherapart. (It's like Sega made the Dreamcast easy to hack on purpose)
The pinouts and their corresponding numbers are the same on both diagrams.
Step 7:Using the pinout diagram from the previous step, you can see that Idon't have anything grounded in the first picture. I chose to take theground and supply voltage from the power supply terminals just to makesoldering a little easier (as seen in the second photo). By the way,that yellow stuff on the solder joints isn't flux, it's actually gluethat I added afterwards to make the joints a bit more secure.
Now, I used wires about 20-25cm long, but that may have been a bitexcessive. Not a problem, but make sure you have some cable ties if thewires are too long.
This mod will tell you how (assuming you have some decent solderingskills) to add a vga port to the back of your Dreamcast, forconsiderably less than the cost of a commercial VGA box which does the exact same thing. No IC's are involved here, just regular components,like capacitors, resistors and diodes. I plugged my Dreamcast into myLCD monitor, and it works like a charm.
Tools Needed:
No. 2 Phillips screwdriver
Wire cutters/strippers
Soldering iron
Dremel + cutting bit (steel bur or cutting wheel works well)
Materials Needed:
3x 220uF capacitors
2x Silicon diodes
2x 4.7Kohm resistors
2x 150ohm resistors
1x Slide or toggle switch
1x Female VGA port
1x 3.5mm stereo audio jack
Solder
Electrical tape
Step 1:
Remove the four screws on the underside of the dreamcast. There will beone in each corner. If you have a modem for your Dreamcast, remove itto expose the 4th screw.
Flip the whole thing right-side up and take off the top panel. Makesure you didn't leave a disc in the drive.
Step 2:
To remove the GD-ROM Drive, remove the screws holding the metal assembly to the other metal chassis.The whole GD-ROM drive assembly lifts out, metal chassis and everything.Don't lift out only the plastic part, take the whole thing.
Step 3:
To remove the PSU, remove the screws that hold the power supply in place. Unplug that white connector that connects up to the power switch. After that, pullthe power supply straight up off the chassis. The power supply justclamps itself onto 6 thick wire terminals, so you don't want to put anyundue stress on either part.
Step 4:
To remove the mobo sheild, remove the ribbon cable from the controller plug connector board to themotherboard. Do yourself a favour and remove the fan power cable. Remove the four screwsthat hold the board in place, but don't try to remove the board justyet. Remove the screws which secure the metal shield in place, and liftit off, enabling you to remove the connector board. You'll have toremove the plastic bezel as well.
Step 5:
Now it's time to remove the motherboard, if there are any screws at this point, remove them. You'll have a mucheasier time if you lift it from the front of the board, as shown in thephoto. In this picture, you can see the power connector I was talkingabout earlier, in the upper right-hand corner of the board. Don't worryabout the rubber heatsinks on those two square chips, the heat-pastewill keep it adhered adequately onto the chip. If it does come off,just put it aside until you're ready to put the Dreamcast back together.The heatsink is important. Your Dreamcast won't last more than about 10seconds without crashing if it's missing (first-hand experience).
Step 6:
The circuit we're going to use is made of reasonably standardcomponents, so you should have no problem getting what you need fromyour local electronics supplier. You could probably get this stuff at the CrapShack, but you may havetrouble finding 150ohm resistors. Everything else will be there, but will be overpriced.
Anyway, as for the capacitors, the negative side should go towards theVGA connector. All of the pins on the VGA connector marked with a blackdot must be grounded. The ones with white dots are unused.
By the way, if you want to add an audio jack, just use pins 2 and 3and wire that to the right and left terminals on the jack. Ground theground pin on the jack. I can't tell you, by the way, which one's leftand which one's right, so you have a 50/50 chance of getting it right.My stereo's messed, so I can't tell you whether I picked the right one.
Do yourself a favour and don't try to solder on the top of the board.Flip it over, and you'll see some solder dots that are spaced furtherapart. (It's like Sega made the Dreamcast easy to hack on purpose)
The pinouts and their corresponding numbers are the same on both diagrams.
Step 7:
Using the pinout diagram from the previous step, you can see that Idon't have anything grounded in the first picture. I chose to take theground and supply voltage from the power supply terminals just to makesoldering a little easier (as seen in the second photo). By the way,that yellow stuff on the solder joints isn't flux, it's actually gluethat I added afterwards to make the joints a bit more secure.
Now, I used wires about 20-25cm long, but that may have been a bitexcessive. Not a problem, but make sure you have some cable ties if thewires are too long.
Step 8:Afteryou've soldered all of the stuff, cover the bottom of it with electrical tape to avoid shorting it out on something.
Don't solder the wires to the VGA connector until you've made a holein the case in which to mount it. Thread the wires through the hole and then solder them to the connector. It's just easier to mount if you do itthat way. Also, if you made the hole too big, the metal tabs on the VGAconnector will cover the gaps.
Step 9:Follow steps 1-5 in reverse order, making sure you don't miss anyconnectors. Screw everything back in. If the heatsink came off, put itback on. Don't force anything, and make sure there's nothing that couldshort out the mainboard (like a loose screw underneath)
I routed the wires through to the front of the Dreamcast, and put thecircuit board on the corner of the GD-ROM drive, where there's thatlittle flat spot in front of the black plastic. Whatever works in yoursituation I guess.
Put the cover back on, and screw everything in place, and make sure thedisc can spin freely when put in, otherwise you need to crack it openagain and just move some things around until it fits well.
Mount the VGA port, VGA select switch, as well as the stereo jack, andplug it all in.
Sat Aug 06, 2011 12:44 pm by 
