Dev. Box suddenly stopped outputting video

Hello, everyone.

I was using my Dev. Box when it stopped outputting video. Everything else works, but the video is completely gone. I've tried both VGA (what I was using when it went) and video out. Both produce a black screen (VGA produces a signal as the monitor doesn't go to sleep), I hear the development kit boot jingle, and everything else appears to be working (CodeScape works as does GD Workshop and the Debug Adapter Checker). After coming across a thread here about re-soldering the connectors which go between all the boards I figured I would give it a shot. Being new to soldering, I'm concerned about the state of the joints that I've posted below. The first image shows what I assume an okay connector looks like (Katana board going to DA board). The next images are of the DA board's connector going to the Katana board, the last one is the SCSI-A connector. The white residue looks abnormal and some of the joints look like they don't even have solder applied (or very little).

I am going to clean the residue, resolder, and report back. Hopefully it works out. If anyone else has had this issue, I would really like to hear any suggestions for a solution, even if it's what I've proposed here.

Katana to DA connector

Spoiler

DA to Katana connector

Spoiler

SCSI-A connector

Spoiler

 

Well theres your problem

 

I resoldered the SCSI-A connector and the board connectors for the Katana and DA (all three) and it has not improved my situation. It's currently 04:22 for me, so I'm going to try again on Sunday.

EDIT: Now I feel like an idiot. After searching for "Dreamcast video no audio", I think it's the DAC.

 

Update

After acquiring a basic hot air rework tool, I have managed to successfully desolder the 315-6145 part and solder a "new" (from eBay) replacement part. Unfortunately, like most electronic components from eBay, I believe there is an issue with the part I received. It wasn't guaranteed in the first place, but it was worth a shot. When power is applied, I get video (haven't tested audio), but the colour is incorrect (a pink hue is applied to the screen) and the framerate seems to be somewhat faster than before. This leads me to believe that there's an issue with the chip's sync abilities. I don't have the equipment necessary to perform any testing beyond continuity tests, even then, I don't have probes with sufficiently small endpoints. The success of the replacement process is based on observation of the solder joints, which I went back over to ensure they were as good as could be for visual inspection. There are no bridges or dry joints from what I could detect.

I'm curious if the part 315-6258 is a suitable replacement. Looking at this commit message for MAME, it would appear that both chips perform the same function, with one being an earlier revision. I'm going to get another Dreamcast (hopefully one that is just having GD drive issues so I'm not sacrificing a perfectly good unit) and replace the IC in the development kit with the one from a retail Dreamcast. I'll most likely have another update in a week's time or sooner.

 

Final Update
Okay, I think I just missed one or two pins with the chip I received from eBay. After switching the chip with the one from the retail Dreamcast and getting no video output issues, I decided to solder the presumed faulty chip from eBay into the retail Dreamcast. This occurred about two weeks ago, sorry for not posting this sooner, I've been rather busy working with the Dreamcast again. A very fun learning experience, to say the least.