Dreamcast-Talk.com

MoeFoh wrote:Cool, have considered a GDEMU for the VA1 Dreamcast?

Not for now, because it is expensive for the region where I live. I have a collection of consoles, which I intend to keep as original as possible, in addition to having some spare SPU3200 units.

Hello!

Unfortunately, I won't be able to answer whether the 171-8129A board is compatible with both 5v (VA0) and 3v3 (VA1), even though there is a VA0 and VA1 using the same board model (171-8129A), with integrated circuits of the same part number and using the same laser model (R48GH), I didn't have the courage to test the 171-8129A GDROM board from VA1 (3v3) on the VA0 motherboard (5v). However, I did the opposite, I took the GD-ROM from the VA0, which has the same 171-8129A board and tested it on the VA1 and it worked without problems.

I spent the last 3 days of my vacation in January trying to get the VA1 laser working as close to the VA0 laser and I managed to do it, it was hard work because:
1- I changed the plastic compartment of the reader, but I used the original motors and gears from the VA1;
2- I adjusted the height of the laser track
3- Adjust the height of the disc clamp

Even with the steps above, the reading was irregular, one moment the reading was good, another time the disc (original or CD-R) would not boot. So I had the idea of cleaning the internal part of the laser, the internal part of the lens and the mirror that is inside the R48G, I cleaned everything and when I tested the reading it got worse. That's when I realized that the suspension where the lens is located is not a fixed location, it is also adjustable, so I kept adjusting, testing, adjusting, testing until the point where I managed to get the laser to behave the same as the VA0, the adjustment was so good that the potentiometer, which was at 696 Ohm, remained at 850 Ohm, working with either the original or CD-R.

Reading good or bad can be HIGH LOW LBA disc you have to get it loading both or have many discs not loading and lots of other working perfect

These are images I never shared before. I use it to help me calibrate 
Dreamcast reader. 

It's common for Dreamcast reader to get bad after some time. However, 
the cases I saw could be fixed by calibrating the reader. There is a 
screw on the lens block that you can adjust, and depending on what you 
do there you'll make it read better or worse. I'm lacking photos at the 
moment, so you'll have to look somewhere else for the location of this 
screw, and for instructions of how to change them. 

What I noticed, is that bad readers have difficulties recognizing multi 
session discs (selfboot discs). What also noticed is that it also 
depends on where the second session start. Some readers won't work fine 
for most releases (where second session starts near the beggining of the 
disc), others will have difficulties with discs where session starts 
close to the end of the disc (too many CDDA, or big games generated with 
bin2boot). If that's your case, calibrating your lens should fix it (I 
take no responsability though xD). 

These discs can help you calibrating your reader. They're Dreamcast 
layout discs with extreme cases: second session starting in the 
beggining and in the very end of the disc. If can know if they were 
recognized correctly by the noise Reader does. If you keep changing the 
reader's screw, you'll notice that there's a point where it recognizes 
great the first disc, but won't read the second disc. There's also a 
point where the opposite occurs. You'll need to find a point where both 
discs are recognized fast, that should be the ideal adjustment. 

Since these discs you'll be used as reference, I recommend recording 
them on a nice CD-R brand in a moment close to the calibration. I mean, 
don't try to use the damaged ones your recorded one year ago on the 
cheapest CD-R you could find. 

I calibrated my reader twice on my 2000 console during its lifetime, 
using these discs on the second time. My Dreamcast is still awesome. I 
played for 3/4 years intensively, and used it for all my releases, so 
you can have an idea of how long these things can last if you 
re-calibrate it.

low lba
https://mega.nz/file/WvhnxRLI#m1RLgSv5c ... ROJjwJD75I
High lba
https://mega.nz/file/2q5wEIRR#HFoxlq_Yz ... TK3Xpuy-Fg

I have used the above to make many non reading Dreamcast work again..

don't forget you can swap pc cd rom lasers for gd rom lasers.
it does work.

my model 0 is using a pc cd rom laser. (loads real gd rom disks and cd-r's)
i've had luck using older pc cd rom drives.
try 2004 and older.

the ribbon cable will align one/two pins off but it does work.
once you get the ribbon cable seated correctly then tweak potentiometer until it reads real gd rom disks.
the main issue is finding a laser that will swap without having to modify the rail pieces or gears.

always keep old pc cd rom drives because more than likely other consoles besides dreamcast could be fixed?
i have yet to try but i'd bet sega cd, sega saturn, etc. and many other older cd based systems could be fixed the same way?
one i would really love to fix would be a neo geo cd

either way if you have spare cd rom drives why not give it a try?