dreamcast problem revisited

[danny_galaga]

I started a thread a while back about a problem my friends dreamcast was having. The thread is a bit of a mess, and I have clearer description of the symptoms now, by way of a screenshot

[danny_galaga]

I have tried the 'reseating the power supply' trick, even though as you can see from that screenshot, it wasn't likely to be that. Someone on another forum suggested that maybe the caps in the power supply are playing up, causing rippling. I'm thinking that sounds plausible. If no one comes up with anything better. I will replace the caps in the next week or so and report back.

Oh, the screen shot is Silent Scope, in case you were wondering 

[northerngames]

weird could be a cap or the psu but the video chip itself may be shot from overheeating from a poor fan or something.

is all the original RF sheilding inside still?

[danny_galaga]

weird could be a cap or the psu but the video chip itself may be shot from overheeating from a poor fan or something.

is all the original RF sheilding inside still?

I'm hoping for caps in the PSU, because that's all I'm capable of repairing. A bit like losing your keys in a dark alley and then going out to where the street lamp is to fix it 

Fan seemed to be working well, and not much crap on it either, so that gives hope it's not something fried on the motherboard...

[danny_galaga]

Autopsy so far:

[danny_galaga]

electrolytic caps from dreamcast 240V power supply:

1  1000 microF 25V S
2  1000 microF 35V G
3  1200 microF 10V G
4  470  microF 16V G
5  1800 microF 16V G
6  1800 microF 16V G
7   47 microF 400V S

all rated to 105 degrees. Interestingly, they have [M] CE printed on them. DC's use Microsoft CE for the OS. I wonder if that's what it stands for? Strange you would have that written on what seems like an otherwise normal cap though...

S and G being silver and gold. I'm assuming tolerances...

edit: I have been told these are 'low ESR' capacitors, since this is a switch mode power supply.

[CCM]

I'm all for taking stuff apart and trying to fix it, but you can get a dreamcast on ebay for $20 or less.  Doesn't seem cost effective to spend a lot of time trying to repair one.

[danny_galaga]

Ok, an update. I managed to pick up another dreamcast for only one buck more than the last one.  When i tested it this one turned out to have a broken gd rom drive. But at least the console itself was working. So, while i was at  it, i tried putting the new power supply in the old machine. Same problem. Therefore, my worst fears have been realised. Something (probably graphics chip as northerngames suggested).

Still, i made one out of two by taking out the gd rom drive from the old one.

CCM, I forgot to mention it on this thread, but i am in Australia. DC's go for way over 50 bucks- for broken ones! So it is definitely worth my while having a play, since freight from overseas is a killer on large packages.

[CCM]

CCM, I forgot to mention it on this thread, but i am in Australia. DC's go for way over 50 bucks- for broken ones! So it is definitely worth my while having a play, since freight from overseas is a killer on large packages.

Damn!  That sucks... sorry, didn't realize you were from Australia!

[gavkiwi]

Hey Danny, I know ur in Australia, how much just out of curiosity is a Sega Dreamcast in the land of oz?

[Slippyblade]

Holy cow...  I work in a video game store in the states and we sell em for $20usd.  I'll have to look into shipping costs and see if it's cost effective to mail you a bunch to sell. 

Slippy

[danny_galaga]

Holy cow...  I work in a video game store in the states and we sell em for $20usd.  I'll have to look into shipping costs and see if it's cost effective to mail you a bunch to sell. 

Slippy

Yes, do that, could be interesting. Would have to ship more than ten at a time is my guess. Then it's a matter of how easy it is to get step down transformers (curse sega for putting the supply inside the machine). There was a company in the UK that sold switchable power supplies for the DC, but that product seems to be long gone...

gavkiwi, the first one i picked up from a mate for 50 bucks. the second from ebay for 51 bucks! Was a poorly worded auction that implied pick up only. It wasn't.

here's some aussie ebay listings...

[HaRuMaN]

I want the blue swirl logo...

[gavkiwi]

Holy cow...  I work in a video game store in the states and we sell em for $20usd.  I'll have to look into shipping costs and see if it's cost effective to mail you a bunch to sell. 

Slippy

Problem there, is the states uses NTSC, and Australia is PAL video format, not to mention, voltage is totally different.

[danny_galaga]

Holy cow...  I work in a video game store in the states and we sell em for $20usd.  I'll have to look into shipping costs and see if it's cost effective to mail you a bunch to sell. 

Slippy

Problem there, is the states uses NTSC, and Australia is PAL video format, not to mention, voltage is totally different.

Pretty much every TV now can run both NTSC and PAL. I found this out AFTER i bought my PAL N64    I have a NTSC Jaguar that works fine on all tellies I've tried it on.

Power would have to be done with a step down transformer, which i suspect would kill the cost effectiveness of the exercise. These would have been brilliant:

http://www.consoleplus.co.uk/product_info.php?pName=dreamcast-universal-power-supply

But it looks like it's been a long time since they made any