Failed Motherboard VGA Mod?

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itsthinkingstill
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Failed Motherboard VGA Mod?

Post by itsthinkingstill »

Hello!

After some unique circumstances, i got myself another Dreamcast for nothing (cause when can you not have enough:p)

Looked promising but there is no video/audio, so got down to eliminating the problem.

1)The GDROM is perfectly fine, i can see that its loading fine and the VMU icons will change over to the set game when far enough along.
2)The controller board and fan also are perfectly fine.
3)Took set components over to other dreamcasts and work perfectly so i can be certain these are not the problem.

Since this was clearly the mobo i took it apart and started going over it, and found something on the underside of the video pins.
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It's clear a soldering iorn had been here before, and when comparing what pins had been touched, this seems to match the pins on the ones you would change for a VGA Mod to work.

The pictures actually bring out more detail than what can be seen with the naked eye, but it looks like the main issue is that there is a lack of any solder in two of the pins. I quickly attempted to add some back in but was never able to get the solder to go onto the board, just kept sticking to the iorn. Im assuming because i have not got the board hot enough but im scared i would damage it further.

I would hate to call it a lost cause but does anyone think there is anyhope here in saving the board? Would be a shame since the rest works.

noiseguy
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Re: Failed Motherboard VGA Mod?

Post by noiseguy »

TLDR you need to find someone locally that has the right equipment and can look at damage in detail.

The biggest issue I see is that giant brown scorch mark. It looks like someone was using a hardware store 30W unregulated soldering iron (fine for car stereos, bad for modern electronics) and just made a mess. Issue is this board is likely multi-layer... hard to see the damage without cleaning it up some more. I can also tell you if you're having problems getting solder to stick to that board you probably don't have the right equipment either. If you want more info on DIY for this I can provide more, but I can tell you right now the soldering iron you probably need is more than a replacement motherboard... so how much of this work do you want to do?

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Re: Failed Motherboard VGA Mod?

Post by SEGA RPG FAN »

You need to get out a multimeter and schematic and start checking continuity on those pins back to the nearest components in the circuit. Best case scenario you'll need to reflow/add solder. It looks like someone got the board way too hot. If they burned out the trace, you could repair it with a jumper wire depending on the extent of the damage.
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noiseguy
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Re: Failed Motherboard VGA Mod?

Post by noiseguy »

SEGA RPG FAN wrote:You need to get out a multimeter and schematic and start checking continuity on those pins back to the nearest components in the circuit.
I get concerned with running continuity testing on MBs. I recall years back a guy blowing out every chip on an Amiga 1000 MB using a sweep meter VOM. This still a problem with modern digital VOMs?

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Re: Failed Motherboard VGA Mod?

Post by SEGA RPG FAN »

noiseguy wrote:
SEGA RPG FAN wrote:You need to get out a multimeter and schematic and start checking continuity on those pins back to the nearest components in the circuit.
I get concerned with running continuity testing on MBs. I recall years back a guy blowing out every chip on an Amiga 1000 MB using a sweep meter VOM. This still a problem with modern digital VOMs?
I haven't really heard of any risks. A lot of meters will have a specific continuity mode where it beeps if you have continuity and I think the risks are very low of doing damage. In this case, you're tracing back to most likely a resistor or capacitor and not any potentially sensitive ICs. But as always, proceed at your own risk. Looking at the pictures again, there's definitely trace and pad damage - portions missing. If the pads are gone, I'm not surprised you couldn't get solder to stick. It looks salvageable, but someone really didn't know what they were doing here.
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itsthinkingstill
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Re: Failed Motherboard VGA Mod?

Post by itsthinkingstill »

Thanks for the feedback (for some reason i was never emailed that there was a response!)

I think everyone here is right, and likewise i only have a 30W iron and a lack of skills to fix it as i think i would just wreck it more.

Im obviously not going to chuck it or anything, but going to have to sniff around to see if there is a service or something that could repair it. Maybe at the same time i should just make it a DCHDMI mod?

noiseguy
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Re: Failed Motherboard VGA Mod?

Post by noiseguy »

Anyone competent to mod a dreamcast would be competent to fix that damage (or at least attempt it,) and agree if you don't have the skills that's an option. When you contact vendors, send pics of damage and reassemble it prior to mailing it out.
You know you can buy a replacement V1 MB for $35... right?

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itsthinkingstill
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Re: Failed Motherboard VGA Mod?

Post by itsthinkingstill »

"You know you can buy a replacement V1 MB for $35... right?"

Really? Most i find are 40$ minimum but are generally higher.

From prices it seems its more worthwhile to just buy a broken dreamcast and replace the board ect (which would still leave me with a broken board to fix :P)

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