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MS2930 Chassis + MS2931 Tube - Yellow Tint on Screen

+1 for a desoldering gun. It sat dormant for ages but now I can’t live without it. A LOT of trial and error has gone into learning how to use it. And I think the biggest takeaways I can give is add new solder/flux, work hot and use a stoker frequently to clear the nozzle, every handful of joints really.

You’re welcome to borrow mine @klee123
 
klee123 said:
Just curious, how do you reflow PCBs?
Click to expand...
So let me just quickly walk you through what I saw and did, because it's easy.

A nice solder joint should look like a Hershey's Kiss, good fat base that tapers up clean. 9 times out of 10 you can spot a cold solder joint just visually, you will not see that Kiss, something will be sunk in or thin or there's a line around the through hole where the solder isn't filling in right etc. You can google up lots of examples, but it's an easy "you'll know it when you see it" thing.

On inspection some of the joints on my neckboard were visually questionable, as above. So great place to start. This is again something you can google up for more details if you're not comfortable with soldering, but all this joint needed was a little heat from the tip of the iron to get the old solder flowing, and a little new solder added to bulk things back up.

No reflow ovens, no nonsense, just a connection that wasn't very robust, heated up and re-soldered to get it clean and moving electricity again.

Boom, I had blue back. This is a few minute job, it's easy. And generally speaking you can't hurt things. If you see a joint you're not sure about, hey, give it a little reflow and solder love, it might help.
 
I have a similar problem to @klee123 .

I have no red on my 2933. I just rotated all the transistors on the neckboard to see if that's the issue. I also reflowed some suspicious looking solder.
 
Have yet to reflow, but I did two things today, since I managed to get the transistors/heatsink(which was an absolute pain in the ass with a soldering wick) out:

1. Replaced the transistor + Heatsink for 32X with one from the broken chassis which had no colour issues. Result: Blue colour is still missing
2. Replaced the zener diode with the one from the broken chassis neckboard. Result: same as #1

Think change the diodes too tomorrow then do a complete reflow then see what happens.

It's a shame this has this color issue, because in terms of stability, it's much better than the tube/chassis which originally came with the Blast. Not to mention it's burn free too.

Have to say tho, it's kinda fun, although my only fear is anything which can happen during any testing which can kill the tube.
 
Well, after spending half a day changing neckboards, zener diodes, reflowing suspcious solder joints.... I've finally got some progress.

Here's what I did initially.

1. Initially did a continuity test from the Jamma edge (Pin 12 on Solder side) to the Chassis connector. Got beep = Jamma wiring is good!

2. I reflowed some suspicious soldering points on the replacement neckboard and was able to get Blue which is a start....

Blast City Woes - 1 - Copy.jpg


3. I then decided to change the neckboard of the original which came with the blast and after 30 seconds after switching on, the picture turned off and smoke started to emit from the back. Shocked, I immediately turned the power off, but regrettably couldn't see the exact location of where the smoke came from. I figured I should turn the power off first to avoid any irreversible damage to the tube.

4. Since I believe the original chassis and tube were killed due to the chassis being faulty, I was going to assume the worst and that my replacement tube was also cracked like the original. I switched back to the replacement neckboard and thank god, the tube is still alive!

I played around with the RGB settings and the flyback screen controller and ended up with this result:

Blast City Woes - 2 - Copy.jpg


I noticed that the Blue bar is now bleeding to the right side of the screen and the text is doing the same too. Running the game shows it looks much better than before with just the yellow tint, but yeah, will need to wait till next weekend to work on this again.

But yeah......PROGRESS!
 
Glad you made some progress and that the fried electronics didn’t damage your tube.

As for your blue bleeding, the blue drive and/or cutoff may just be set too high. Do you see a change when you lower them?
 
ShootTheCore said:
Glad you made some progress and that the fried electronics didn’t damage your tube.

As for your blue bleeding, the blue drive and/or cutoff may just be set too high. Do you see a change when you lower them?
Click to expand...
I did and is still didn't change the overall result.

Will get back into this at a later date.
 
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