Problem with Dreamcast VGA cable - SYNC lines?

I bought one of those cheap Chinese Dreamcast VGA cables and was so excited to not pay $100 But my excitement quickly dissipated once I got it hooked up. On my LED TV (running through a VGA to HDMI upscaler) I got some fat black lines jumping around horizontally on the screen. Hooking up to a LCD monitor gave a stable image, but there are two tiny black lines that go thru the center of the screen horizontally.

I thought I read somewhere (couldn't find it again) about someone having a similar problem with SYNC and resistors on the internal VGA hack. I'm wondering if this is something I can fix without paying to ship the dang thing back to China. Any thoughts?

 

A little offtopic, but why you didn't bought Hanzo? Custom designed VGA box with focus on quality. And price is $60, much lower than $100.

 

I paid less than $20 and all the reviews were good. I guess I just got a dud. But even $60 is too much for a cable. I'm sure his quality is excellent. I just don't have that kind of money for a cable. It's a scarcity problem, so people are piecing these together by hand.

update: coincidentally I think my LCD monitor and VGA to HDMI upscaler are bad

 

This one is very good and 37 euros max including shipping (and it got a life-time warranty!) : https://www.facebook.com/Cabous.Dreamcast.VGA.cables/info


If you wanna fix it yourself, check in the vga connector. There could be components missing. Reference schematic: http://bit.ly/1dRbjnN

Good Luck!

 

Well even more strangeness.. I used the VGA cable that came with my HDMI upscaler, connecting it to the VGA Dreamcast cable with a mini gender changer and the weird lines disappear completely after the initial Dreamcast boot logo. Only problem now is the screen bounces a bit.

I'm not even sure what to think after all this plugging, unplugging adapters, etc. My brain hurts! lol

 

have you tried hooking it up directly to a computer monitor? with a known good working cable, that said it may just be poorly constructed or poor quality parts. complain to them and they may send another one.

 

I hooked the DC up to a really old LCD monitor and it seemed fine except for some lines (artifacts) on the screen - pretty sure that was the LCD monitor though. No bouncing. Going to double check that in the morning. Also digging an old CRT out of the closet to test with.

I *think* part of the problem was not getting a solid connection with the HDMI upscaler. Using the other cable plus the gender changer probably fixed that. Maybe the DC VGA cable pins were not long/wide enough. I'm thinking the bouncing has something to do with poor upscaling of the DC VGA signal.

 

Also, the additional cable could have added some required resistance on the sync lines.

 

Here's the upscaler I have, in case anyone has experience with it.
http://www.lenkeng.net/Html/Product/vga-to-hdmi-converter.html

 

Well after a lot of testing.. the good news is my DC VGA cable is GOOD. I busted out the crap CRT monitor and it worked perfectly! The bad news is something's messed up with my HDMI upscaler.

Can anyone recommend a good component/VGA -> HDMI upscaler that won't break the bank? I think I paid $23 for this one:
http://www.lenkeng.net/Html/Product/vga-to-hdmi-converter.html

 

I got this one, though I think I paid less for it, worth looking out : http://www.ebay.ca/itm/NEW-Mini-PC-...eo_Cables_Adapters&hash=item41771f758a&_uhb=1

The output is a tad off-centered, but it preserves 4:3/16:9. No amazing quality in upsampling, but not bad either (I don't see the difference really), but does the job quite well if you have no VGA port, still WAY (WAY) better than s-video.

FG

 

Thanks. Who knew getting a new TV would be such a pain in the you know what? I also need to get 3 component cables to HDMI.

 

Working with the company I bought the upscaler from to see if they can help me fix the problem. Short of the bouncing lines, the picture looks great.. Can't wait to enjoy some Dreamcast in VGA!

 

So the company I bought the upscaler from ran out of stock and opted to refund my money instead of sending me a replacement. At least my money wasn't wasted, but now I'm in need of a proper solution.

Funny thing is, I was messing around with the unit the other day and discovered the problem may be heat-related. It's been really cold here the last few days.. and when I plug it in, it works fine until it heats up a bit. I may try putting some heatsinks or thermal pads on the chips and see what happens. Will post my results.

 

Could also be the power supply for it isnt too great, if i use a sub par or overpowered adaptor on my GBS 8220 it has issues and gets very hot, you could try the heatsinks and thermal pads / paste it worked out well when i did this to a router.
Good thing you're not losing any money on it too.

 

Good idea about the power adapter. I've been rethinking my setup and looking at standalone VGA to HDMI adapters for the Dreamcast. Think I'm close to something working, without spending too much.

I also got the problem to happen on several new cold boots, so I guess my overheating theory is out.

It says nothing on the unit itself.. but the AC adapter is DC 5V 2A out. It feels REALLY light when I pick it up. Hmmm?

Voltmeter correctly reads 5v~
Shucks.. I found another power brick with the same specs, but it has a different sized plug

I could solder USB to the board ~ I just wonder if the power brick is correct for the unit itself

Looking at the product page, the power brick pictured does look different, but I can't make out any of the specs from that image
http://www.lenkeng.net/Html/Product/vga-to-hdmi-converter.html

 

So I could have this output 4:3 480p? or 16:9 720p/1080p ?

 

It preserve the input ratio. But I must admit I'm not 100% sure if it converts to 16:9 or if it spits 16:9 with borders. At least I've tested with shenmue and it gives me 720p but includes black borders on the sides so the gamescreen isn't stretched. Though it's not completely centered (left/right). I haven't tested, but I guess the few games that output 16:9 would be just finein 720p 16:9.

 

So I'm guessing if you wanted to stretch the image to 16:9 via your TV, it wouldn't work because it's already outputting 720p/1080p with the 480p input slightly off centered ?

I'm asking because normally I prefer native resolution, but sometimes I like to go widescreen.. I know.. lol

 

I can't test right now, but I don't think you could stretch as you said unless you tv can already stretch 16:9 input. Though I recall someone on here saying he got a different cheap vga2hdmi adapter that shrinks and doesn't preserve ratio, if you really wanna stretch the image!