Some time ago I acquired a brand new R7 Dreamcast. Also owning an official black Dreamcast top, I decided to open the R7 up and replace the top of the casing with the completely black one. While doing that, I saw that the R7 has a regular Samsung drive, like my PAL Dreamcast. Never had any issue with that one, even after 8 years of playing. So now for my question.... After testing the modded R7 with a few games, I decide to put in the Broadband Passport disc (JP, comes with the HTK-401 BBA). First of all, this disc boots automaticly, even when you are in the menu mode with autostart off... After messing around with it, and not understanding what the characters mean, I decide to load my Propeller Arena disc (CD-R)... It won't even load. Then I put Street Fighter Alpha 3 in... Won't load... I manage to load Code Breaker and running a demo disc that came with my PAL Dreamcast. It loads, makes more noise then I'm used to from my PAL Dreamcast, I play the demo of Space Channel 5, and decide to give Street Fighter Alpha 3 another go. Loads up with no problems at all. Then I try Propeller Arena again, this time loads smooth as butter. No weird noises, no longer loading. Every other game I boot, may it be JP GD-ROMS, EU GD-ROMS in combination with a boot disc, or CD-R's, all loads perfectly, until I throw in the Broadband Passport disc. Then my Dreamcast appears to be having problems with reading discs again. Does the Dreamcast recalibrate itself or something after a while/loading other software? Or should I be thinking about doing a laser tweak? I suspect that the Dreamcast sat on a shelf for a couple of years, doing nothing at all, so maybe the drive assembly grease dried up, giving it focussing trouble? Before I forget.... I also replaced the power supply with a European one, so that I can play without a step down converter. Could somebody advice me?
In all my years of popping whatever I felt like in my DC I've never once had that problem nor have I ever heard of it. AFAIK the DC does park the laser like every other optical drive in existance in a form of recalibration. I've seen PS2s that, when this doesn't happen properly, won't read disks until the laser head is pushed to the rear of the drive and allowed to move back into a normal position. I'm no expert on the topic but you've piqued my interest.
this happened to me recently... Have you tried cleaning the laser? Try these: worked for me (AT OWN RISK!!!) At proper power off (opening disc cover at BIOS) the Dreamcast will park the laser sled/carriage near the center hub. Some times it doesn't get all the way there. With Dreamcast powered off move the laser sled to the center hub with your finger. DO NOT TOUCH THE LASER ITSELF!!!! You will hear a single click when you get it correct. Try your disks again. Also see if the sled is not crooked or unlevel. make sure that the laser is moving up and down. To test this power on with disc cover open and no disc inserted. Press down the switch so the Dreamcast thinks there is a disc in there. Watch the movement of the laser. If it moves up and down in relation to the sled then your OK. Another thought: reseat the power supply.
The laser is able to move up and down (vertically that is). When I trick the Dreamcast into attempting to read the disc with the lid a bit open, I see it trying to focus like every other Dreamcast. The lens is clean, it was clean when it arrived, and has been cleaned right away after the first time I encountered the issue. Also, I always do the "open lid, laser back to parking spot" method to load other software or power it off. When I got the reading problems, first thing I did was look up some of the Dreamcast laser tutorials, but you both suspect the gears/alignment, which is making a lot of sense actually... Especially when I think back how the packaging looked like... The postal services really throw with stuff :crying:. I hope to have some transplant parts soon, but meanwhile I'm gonna compare the drive behavior with my PAL Dreamcast and follow the advice you gave me. I hope the drive isn't busted.
I finally got the parts I wanted to test. I replaced the powersupply by a brand new one, a Sega made one. Didn't make any difference. Also checked the gears and everything, looked all fine to me. Without the case on I noticed that with some discs it's focussing all the time, even when nothing is being read. I decided to do a drive transplant after that, and the Dreamcast works perfectly now. I decided to open up the GD-ROM shielding, and happen to notice there was a Yamaha chip in it. The ones I encountered before always were OAK. Funny to see a Yamaha chip in a Samsung drive though, I thought Yamaha delivered complete drives, not only the chips. Maybe the Yamaha chipped drives are more picky then the OAK/Samsung ones.
Thats really strange - are you sure this drive has never been opened before? I have seen pictures of the GD-Drive board which uses an OAK OTI9220 chip, but have never seen one for real. Heres the only picture I have ever seen:- The only two drive board variations I have seen for real are the Yamaha Drive which uses a GD-board using three Yamaha chips. Heres some pics of mine:- ...and the Samsung Drive which uses an almost identically designed GD-board, but uses two Sega chips, and one Toshiba chip:- They are pretty much identical in layout which leads me to believe the Sega chips are probably just re-labeled Yamaha chips. One minor difference is the drive lid switch - on the Yamaha board its not very reliable and is prone to the contacts becoming dirty/corroded which causes the Dreamcast to reset thinking the drive door is open (You can take apart the switch and clean the contacts if you are good with fiddly jobs) The Samsungs boards lid switch seem to be much more reliable and I have never had to fix one yet. On the flip side I have had to pot tweak many Samsung lasers (R48G) but never any Yamaha lasers (SPU-3200) although I am basing this off the limited number of consoles I have repaired. I would be interested in learning more about the Dreamcast GD-Drive - I wonder how the drive revisions relate to production dates, countries, etc. I had assumed that the Yamaha drives were the first produced, since Sega worked with Yamaha to develop the GD format. However, the last Dreamcast revision 'model 2' which has a combined GD-Board and motherboard uses a Yamaha laser (SPU-3200) which makes me wonder if perhaps the Samsung and Yamaha drives were both used randomly throughout the Dreamcasts production?
I wrote a tool to probe the GD's firmware revision, date and other info. http://dcemulation.org/phpBB/viewtopic.php?f=29&t=97767 I havn't tried to run this on all my DCs (havn't been home since I wrote it), so I'm not sure how the revisions match up with hardware revisions. The one I posted from my dev DC is from a VA2, the type that has the GD controller integrated into the motherboard.
I'm pretty sure the drive wasnt opened before. As you know the shielding contains a soft foam edge that covers some screws. This was not touched at all. The Dreamcast was brandnew. Tomorrow I will make a picture of the board.
The pictures (click to enlarge): As you can see, this one has Yamaha, Toshiba and Sega chips. The shielding says Samsung, but the drive assembly doesn't look like other Samsungs I have. And the performance of this drive is bad, really bad...
Thats awesome work! :icon_bigg Have you managed to dump the actual GD-Drive firmware, or is it just the revision information it probes? Ill have to try this once I have a coders cable :nod: Thats really interesting - its like a 'stop gap' between the two drives boards I have. It definitely has a Yamaha laser (SPU-3200) but it also has the newer style lid switch used on the Samsung boards. It seems even more likely to me that they just re-labeled those Yamaha chips as Sega chips. Perhaps your board was made at a point where they had used up there stock of one of the Yamaha chips, and so replaced it with the Sega labelled ones, but they still had stock of the other Yamaha chip? Are you sure that its the board causing the bad performance? Id be more inclined to believe its the carriage/laser assembly. The only way to prove it for sure though would be to swap over a fully working assembly and test the performance then. <EDIT> Looking even more closely at the pictures it looks like it has a Samsung laser carriage assembly aswell as the casing, but just the Yamaha laser! - I wouldnt be surprised if that was the reason for you problems. The Yamaha and and Samsung laser have different 'grooves'. I remember reading on a forum a while ago that you cant just transplant the different lasers unless you transplant the guiding rods aswell, and even then it only works one way - the other way you end up with graphical glitchs. If you have a picture of the underside of the laser mechanism that would confirm it one way of the other. Found the old thread here:- http://nfggames.com/forum2/index.php?topic=2776 Mentioned half way down P.S. Slightly OT but does anybody know of an easy to find equivelant for the Dreamcasts laser ribbon cable? Or another easy to acquire ribbon cable with the same pin pitch and length that can be trimmed down? I have two laser assemblies which just need a new ribbon cable to work again (somebody else had attempted to repair them and had torn the cable in half OH
The drive came from a Regulation 7 Dreamcast. As far as I know, this version was released late in the Dreamcast lifespan. The laser differs from the one I saw before. Even after laser tweaking, I couldn't get the drive work reliably. I don't use it anymore. As for the ribbon cables, I noticed some PS-One lens extension cables look like it's compatible with the Dreamcast one. I have a type/manufacturer name of those cables, which I will post later on.
That would be great - thanks :icon_bigg If it helps I know they are 16 pin FFC cables and are 68mm long and 16.5/17mm wide ----------------------------------------------------------------------- Today I just received a PAL Dreamcast in need of repair, inside was a Samsung laser/drive, but when I looked closely at the lid switch I noticed it was the old style switch, which I had previously thought was exclusive to the Yamaha drive board. Curious, I opened it up and to my surprise I saw a Yamaha chip aswell! It has one Toshiba, one Sega and one Yamaha chip - pretty much identical to your board, but instead of the newer style lid switch yours has, mine has the old style switch. Also of course mine uses a Samsung laser and not a Yamaha like yours. It seems more and more likely to me that Sega just used whatever parts they had available at the time when making the GD-Drives. It seems to be pretty much random what parts were used to make the GD-drive - Unless anybody knows differently? I still havent come across the GD-Board using an OTI 9220 chip. Does anybody know which models they were used in? Was it just Japanese launch machines? I would love to see some pictures of both sides of the board if anybody has it and wouldnt mind. Also, anybody with an unopened Japanese, US and PAL launch machine - is there any chance you could pop open you lid and tell me what laser is inside? To tell which one it is just look at the laser and match it to this pic (For safety dont do this with the Dreamcast turned on, even though it shouldnt matter!):- The Yamaha laser is on the left, and Samsung laser on the right. (Notice the curved shape of the Yamaha laser) If you are unsure a quick picture of the laser would be great :icon_bigg
I havn't been able to dump the firmware (it's quite possible that there simply isn't a way to do so from the DC in software) but have found a number of undocumented commands that may possibly have something to do with accessing the firmware. All my work though has been done against the last revision of gd-rom (that I know of) which is integrated into the motherboard, so by that point they may have removed commands which may be present in earlier revisions. I know for one thing that 5.xx firmware revision drives have issues with DMA that makes it more difficult to get a proper 'full dump' of a disc. I've never yet tried to document the drive boards. I've got a huge amount of broken DCs back home (maybe 20-30), I'll put it on my to-do list to write down chip numbers from the GDs.
I just gotten the psx extension cables.... they are nothing like the Dreamcast one, or even looking like the picture I saw at the webshop. So this is not an alternative source for Dreamcast ribbon cables. The Dreamcast cable manufactur + product number: Sumitomo AWM 2896 80C VW-1 -F- . The AWM 2896 80C gives me some Google results, but looks like wholesale. I managed to find one in an el cheapo discman btw.
Thanks, I hope you didnt buy the psx extension cable just to test it for me? :redface: I just wanted to update that I have eventually managed to find an equivelent ribbon cable made by Sony with the code KSS213 (although that code doesnt seem to specify the length of the cable) It seems to work great, although the one I bought is 1-2mm shorter than the original cable. Slightly OT but does anyone know which chip on the GD-Rom drive board contains the firmware? I am wondering if it would be perhaps possible to de-solder it and read its contents on a chip programmer? Even if it cant id still be interested in knowing. Thanks for the help :nod:
