Dreamcast not displaying video/audio after re-assembly + Pics of damaged mainboard

Discussion in 'Repair, Restoration, Conservation and Preservation' started by Calikitz, Jul 3, 2012.

  1. Calikitz

    Calikitz Member

    Joined:
    May 18, 2011
    Messages:
    13
    Likes Received:
    0
    After re-assembling my Japanese VA0 Dreamcast I accidentally screwed the GD rom drive to the metal shield using one of the long screws instead of the short screws. Got the GD rom and controller port screws mixed up. I didn't notice I had done anything wrong until I tried to boot it up and was getting no video after getting video just minutes before. After researching, I learned about how the long screws can damage the main board if screwed through the GD rom area which is why I am now aware of what happened.

    Now I know my mainboard is now in need of repair, the question is, out of the two danger screw holes on the GD rom unit, did I pick the lesser of the two evils to screw the long screw into? I put it in the back left corner of the GD rom, the front left corner I put the correct default short screw in.

    I took pictures of the damage on the mainboard, its right above the metal capacitor and to the right of and a a bit down from where R621 is written, you an see a metal ring where the screw etched into the board. What exactly did I hit here and how would I go about fixing it? This Dreamcast is pretty important to me as I looked for a VA0 for quite some time, so buying a random new Dreamcast isn't what I had in mind. 044.jpg 045.jpg 044.jpg 045.jpg

    Thanks in advance.

    -Mike
     
    Last edited: Jul 3, 2012
  2. Bad_Ad84

    Bad_Ad84 The Tick

    Joined:
    May 26, 2011
    Messages:
    8,605
    Likes Received:
    1,376
    I dont understand the obcesion with VA0's - they dont do anything special.

    That said, thats pretty easy to fix. Just clean up the area and fix the via you have destroyed.
     
  3. Mystical

    Mystical Resolute Member

    Joined:
    May 3, 2011
    Messages:
    935
    Likes Received:
    35
    from the pics it looks like you have broken a trace, could have been worse, just bridge it with some solder

    i may be wrong, its early ;)
     
  4. Shinebi

    Shinebi Dauntless Member

    Joined:
    Jul 6, 2011
    Messages:
    744
    Likes Received:
    8
    Lucky you, it's not the critical brick-spot on the left...
     
  5. Oldgamingfart

    Oldgamingfart Enthusiastic Member

    Joined:
    Jun 24, 2008
    Messages:
    509
    Likes Received:
    2
    I could be wrong also, but from the photos it looks like the row of five components (either resistors or capacitors) above the damage, connect through to the flip-side of the PCB. Therefore it's most likely the second component from the left in that row has a trace broken, or is being inadvertently grounded by the damage caused there.

    Check for low resistance with a multimeter (in diode mode). If it confirms there is a connection to ground then, as mentioned scraping away some of the damage there may restore the connection. Worst-case scenario is you'll have to bridge the trace to the underside of the board.
     
    Last edited: Jul 3, 2012
  6. l_oliveira

    l_oliveira Officer at Arms

    Joined:
    Nov 24, 2007
    Messages:
    3,888
    Likes Received:
    249

    Wrong. They run HOT and are noisy. :D


    OMG I love my VA0 Dreamcast, as much as I love my NOISY HOT HEADED SCPH-10000 PS2 ...
     
    Last edited: Jul 3, 2012
  7. OzOnE

    OzOnE Site Supporter 2013

    Joined:
    Nov 10, 2011
    Messages:
    538
    Likes Received:
    173
    Hi,

    If you follow the white line leading from those components, you can see the parts are labelled.
    These are inductors, but are generally used for signal filtering, so the labels start with "FL".

    The part near the damage is FL402, this is the inductor for the GREEN video out signal.
    On the VA0 schematics (from the forum sticky), this is confirmed as you can see the trace connects to video port pin A15.

    (The FL402 part is near the right of the "video_dac.jpg" diagram, and the video out port is on the right of the "connectors.jpg" diagram.)

    If the damage has broken the track or even shorted it, I'm not sure why this would stop video output completely unless the DC is capable of outputting component video?? (component uses "Sync on Green").

    It doesn't actually look that bad from the photos? Do you think the board was pushed down quite far?

    I suppose it could have overloaded the DAC though? Or, the damage has gone through some lower layers of the board?
    I'm not sure how many layers the DC board has, but someone on here or benheck is likely to know.

    EDIT: I've just seen on @bacteria's DreamBox build on benheck that the DC board is only two layers apparently.

    What I would do first is to clean the board slightly with a soft brush, and maybe a small dab of IPA (Isopropyl Alcohol).
    You might be able to see the damage more clearly then.

    Do you have a VGA box / cable? Give that a try if possible.

    And yep, a multimeter check is a good idea. Check between either end of FL402 and Ground (any of the exposed copper around or above the screw hole on the left).

    OzOnE.
     
    Last edited: Jul 3, 2012
  8. l_oliveira

    l_oliveira Officer at Arms

    Joined:
    Nov 24, 2007
    Messages:
    3,888
    Likes Received:
    249
    Like I said at the other thread, that damage on the video region would not stop the Dreamcast from booting. So there would be sound.

    And no, the Dreamcast is not capable of outputting YCbPr.
     
  9. Calikitz

    Calikitz Member

    Joined:
    May 18, 2011
    Messages:
    13
    Likes Received:
    0
    Thanks for all the responses guys. I did a heavy cleaning of the damaged area still no video output so I re-examined the entire board in other areas. It seems there is tiny damage from a screw going into the bottom left GD rom hole as well.(the first pics of damage were from a screw in the top left GD rom hole.) I did not notice this mark because it is not as pronounced as the other, I guess the screw did not penetrate as much.

    However, this damage is directly over a bunch of tiny traces which go right to either the GPU or CPU)It's one of the components covered in a metal block so I know it's one of those two.

    Anyhow, these traces are so tiny that I don't know how even an expert could fix it. I will post pics up later to at least give it a shot.
     
  10. l_oliveira

    l_oliveira Officer at Arms

    Joined:
    Nov 24, 2007
    Messages:
    3,888
    Likes Received:
    249
    Yes, it's that one which is preventing it from working.
     
  11. Calikitz

    Calikitz Member

    Joined:
    May 18, 2011
    Messages:
    13
    Likes Received:
    0
    Any idea which parts from this can be salvaged? Going to post a WTB thread for a VA0 mainboard but there's a very small chance I will find someone selling just the board. I have found other mainboards though such as US VA1's for next to nothing. Could I salvage some of the parts from this such as the fan, pipes, GD rom etc. or is it not cross-compatible. I figured the layout of components probably isn't the same on a VA0 compared to a VA1 so I figured the fan etc. wouldn't be useable just the GD rom possibly and the power supply.

    Might be best for me just to buy another JP Dreamcast or a cheap US Dreamcast.
     
  12. OzOnE

    OzOnE Site Supporter 2013

    Joined:
    Nov 10, 2011
    Messages:
    538
    Likes Received:
    173
    Didn't think so. Looks like it's RGB and YC (S-Video) then.


    Ouch, that doesn't sound good. Like @l_oliveira said, the DC would probably have still booted with that top damage alone, so there had to be another reason for the problem.

    Is there a particular reason for wanting a VA0 board? Did you want a Jap BIOS as well? My DC's an early VA0 (PAL UK), but then I did queue up to buy it at midnight on 14th Oct 1999!

    Please upload some pics of the other damage - if there are components nearby which the traces lead to, then it might just be fixable.
    If they lead directly to the CPU / GPU, then it's not gonna be worth the effort tbh.

    OzOnE.
     
    Last edited: Jul 3, 2012
  13. Lum

    Lum Officer at Arms

    Joined:
    Sep 30, 2010
    Messages:
    3,234
    Likes Received:
    43
    Does the Jap BIOS even have any noteworthy differences (excluding game disc region)? US DC can be set to Japanese menus like Saturn before it.
     
    Last edited: Jul 3, 2012
  14. APE

    APE Site Supporter 2015

    Joined:
    Dec 5, 2005
    Messages:
    6,417
    Likes Received:
    141
    AFAIK nope.
     
  15. Tokimemofan

    Tokimemofan Dauntless Member

    Joined:
    Feb 8, 2012
    Messages:
    745
    Likes Received:
    79
    Yeah, the bottom left one probably cut some traces to the SH4. Take an x-acto knife and scrape the lacquer of the ends of the traces and get some very fine wire (take some from a speaker, transformer or other inductor) to bridge the gap on EVERY broken trace, you may need to stagger them to prevent them from bridging, I had to do this on my Laserdisc Recorder laser assembly (that is worth at least $1000) so It should work on this.
     
  16. Hedgeyourbets

    Hedgeyourbets Dauntless Member

    Joined:
    Jul 19, 2011
    Messages:
    743
    Likes Received:
    2
    Sorry to take the thread a bit off topic a bit but there was never a VA0 dreamcast released in the Uk, there were two different varieties of VA1, the launch ones as I suspect you have with a metal fan which is attatched to the top metal shielding and later model ones with the bog standard plastic fans.



    I can see why it would be worth it to repair the VA0 motherboard as opposed to opting for a new cheap dreamcast, while there are few benefits to having a VA0 as opposed to any of the other revisions, the VA0 consoles are most certainly rarer and tend to be worth more money.
     
  17. Bad_Ad84

    Bad_Ad84 The Tick

    Joined:
    May 26, 2011
    Messages:
    8,605
    Likes Received:
    1,376
    I have 2 VA0 Jap consoles sitting in a box =/
     
  18. Hedgeyourbets

    Hedgeyourbets Dauntless Member

    Joined:
    Jul 19, 2011
    Messages:
    743
    Likes Received:
    2
    I didn't say they were super-rare, just harder to come by than revision 1 consoles
     
  19. Bad_Ad84

    Bad_Ad84 The Tick

    Joined:
    May 26, 2011
    Messages:
    8,605
    Likes Received:
    1,376
    I wasnt implying its common - just that they dont seem to be worth any extra with my dealings. =/

    They run hotter and louder, not a good selling point.
     
    Last edited: Jul 4, 2012
  20. OzOnE

    OzOnE Site Supporter 2013

    Joined:
    Nov 10, 2011
    Messages:
    538
    Likes Received:
    173
    Actually, you're right, my DC is a VA1 after all (metal HS / fan). I was getting confused with the VA0 schematics etc.

    (too much DC stuff on the brain - stupid code has been giving me weird dreams).

    OzOnE.
     

Share This Page