@GeekMan1222 only 1 blast unfortunately. I’ll take a look at the daughter board.
- Thread starter JSN_
- Start date
Yes that’s correct. I’m disassembling now
Some pics of the bottom. If this is like a fun puzzle for you to identify cold solder joints, have at it!!
Attachments
Both ends of C704 also look like bad joints. Could be the lighting though.
tiff_lee
Grand Master
R703 just below it looks bad but again could be angle/lighting.
GeekMan1222
Grand Master
As far as I could tell doing the cap installed and reflowing anything that stood out I didnt see any issues during my sanity checks.
The HV daugter board U704 or w/e the number was does have two missing pads from desoldering but those have no connections their just anchor points for two unused pins off the board.
If thats what Advans is pointing out. Not much I can do about it this chassis already had its HV regulation daughter board replaced and the flyback replaced iirc too who knows when, that would have been in Japan. I checked the continuity of all the pins from the edge of that daughter card.
Ill have to rereview and test the work I did yet again and cross reference the block diagrams and things on the MS2931 service manual whenever I get more time to do that.
For all I know a solder joint I missed went bad in the mail.
JSN is sending the chassis back I have a replacement thats known working I will recap test and send out so he doesnt have to wait as long.
The HV daugter board U704 or w/e the number was does have two missing pads from desoldering but those have no connections their just anchor points for two unused pins off the board.
If thats what Advans is pointing out. Not much I can do about it this chassis already had its HV regulation daughter board replaced and the flyback replaced iirc too who knows when, that would have been in Japan. I checked the continuity of all the pins from the edge of that daughter card.
Ill have to rereview and test the work I did yet again and cross reference the block diagrams and things on the MS2931 service manual whenever I get more time to do that.
For all I know a solder joint I missed went bad in the mail.
JSN is sending the chassis back I have a replacement thats known working I will recap test and send out so he doesnt have to wait as long.
Legend as always. Excited to hear the resolution on that chassis when you figure it out!
advans14
Professional
Yeah i cant read it in the pic. But that is prob the one i flagged. I also always reflow the fly and all header’s/ connectors regardless of how they look.
Probably right though some mail action.
I don't think I've ever seen those daughterboard spots with pads, and I've had I don't even know how many go through my hands now. 100?
GeekMan1222
Grand Master
They fall off really easily theres really nothing attached to them
Yea I threw in the towel. Thanks to @GeekMan1222 for being so cool and helpful. I felt like I would have just been going on a wild goose chase with a soldering iron, and while I'm comfortable soldering, desoldering and reflowing... Diagnosing this problem would have taken me who knows how long and he was gracious enough to swap a known working chassis with me.
NOW - If I plug this new one in when I receive it and still get the same issue, I guess I have bigger problems.
There is one thing I did want to check in the meantime to rule out for future issues. I should preface this with "I don't think I have any power issues because the board runs and I get sound"
But I recapped my power supply and sound amp(prior to getting blue screen issue), but I'm unsure how to test properly.
I thought I read somewhere that you can just check for +5V on the JAMMA edge. any other tests to run on the PSU and/or Sound amp to ensure proper voltages?
NOW - If I plug this new one in when I receive it and still get the same issue, I guess I have bigger problems.
There is one thing I did want to check in the meantime to rule out for future issues. I should preface this with "I don't think I have any power issues because the board runs and I get sound"
But I recapped my power supply and sound amp(prior to getting blue screen issue), but I'm unsure how to test properly.
I thought I read somewhere that you can just check for +5V on the JAMMA edge. any other tests to run on the PSU and/or Sound amp to ensure proper voltages?
Running PCB's with no idea what your voltages are is how you don't have PCB's any longer...
Day to day your voltages aren't going to suddenly drop or raise but after recapping it they're likely much much higher than previously.
Look up the jamma pinout, put the black lead on gnd, red lead on 5v. Then 12v. 5v should be adjusted to the 5 - > 5.1 range. 12v can vary a lot more and be fine. Then put in your PCB and adjust it again. Because the PCB will draw that number down. Some more than others.
Unless it's Midway or some other known power hungry PCB consider over 5.10 the dangerous to your PCB zone.
I don't know if it's been asked (and seemingly may now be relevant), but did you try just plugging a 360/PC/DC directly into the monitor over vga? Do we know the game is actually sending an image?
I didn't end up connecting anything over VGA, I do have a 360 somewhere but have to pull that out of storage.
So I can check voltages without having any PCB connected to get a baseline? Didn't realize that, cool.
Yep. And then you have to check again with the PCB attached to get a more proper reading since the PSU will now be under load. How much of a load depends on the PCB.
Just before I sent the chassis to Geekman for a recap it was only displaying Blue with the same setup I have in the cab now.
-He was able to determine that the reason was a bad transistor in the neckboard which was replaced.
-There was a video of it working just prior to shipping back to me, but when I received, we're getting the issue which is the topic of THIS post.
We are thinking something happened in the mail, or that a component just died or was weakened shortly after his testing.
On the topic of voltage checking:
This is a great way to check voltages without busting out the multimeter, JAMMA Passthrough Tester with Buttons https://riddledtv.com/arcade/jamma_testers.html
When I'm switching PCBs I'll put that guy on the harness and power up. Then, adjust to 5v, power off, connect the game board, and adjust again as necessary. Makes it easy!
This is a great way to check voltages without busting out the multimeter, JAMMA Passthrough Tester with Buttons https://riddledtv.com/arcade/jamma_testers.html
When I'm switching PCBs I'll put that guy on the harness and power up. Then, adjust to 5v, power off, connect the game board, and adjust again as necessary. Makes it easy!
