Well I cracked open my friends DC (figured I'll use his as the test:) Since I couldn't get any 4.7 Ohm, I picked up some 10's to run in parallel....remove the controller port PCB, take a look at F1 resistor and its bands aren't what everyone has been saying (?)
This DC has orange / white / gold /gold /green
3.9 Ohm 5% 1/4watt
green im assuming is for it's "quality"
Maybe the factory was running short on the standard stuff that week? I thought it was weird and thought I'd share it ....I'm gonna try with what I have, this DC was left for dead so its not like anyone will miss it either way :p
FYI -- Controller port fix ----oddity
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koz
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This is interesting... enough for me to take my dreamcast apart and check it out, and it looks like your right.
orange = 3
white = 9
gold = x0.1
gold = 5%
green = ?
1/4 watt
3.9 Ohm
5% Tolerance
But even more important, its not a normal resistor. The blue coating and the "F1" label on the PCB, means its probably a fusable resistor with a flameproof coating. Replacing it with a normal carbon resistor (even if its of the same value) is not a good idea, and probably a fire hazard.
I can't believe no one has caught this mistake (unless there are different resistors for different models?). Good eye koz.
orange = 3
white = 9
gold = x0.1
gold = 5%
green = ?
1/4 watt
3.9 Ohm
5% Tolerance
But even more important, its not a normal resistor. The blue coating and the "F1" label on the PCB, means its probably a fusable resistor with a flameproof coating. Replacing it with a normal carbon resistor (even if its of the same value) is not a good idea, and probably a fire hazard.
I can't believe no one has caught this mistake (unless there are different resistors for different models?). Good eye koz.
It looks like batty0 might actually be selling the right part (although his website looks a little shady it doesnt have any specifics).
http://www.dcemulation.org/phpBB/viewtopic.php?t=6307
http://www.dcemulation.org/phpBB/viewtopic.php?t=6307
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koz
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damnit! I was just talking to a guy I work with who knows his stuff with electronics and he said pretty much the same thing....with the "F1" designation on the PCB and he thought he remembered something about blue bodies....but he wasn't 100% sure on that
hmmmmm... I'm working now, but I'll post my model # later, and I have to crack open my DC as well to see if its the same there
hmmmmm... I'm working now, but I'll post my model # later, and I have to crack open my DC as well to see if its the same there
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koz
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ok another follow up
Both models are HKT3020's
Mine has the UD And Made in Japan in lower left of back tag, friends has WK and Made in China.
Yes they ARE fusable resistors, blue body does signify this and upon removal of the bad part, on the PCB it has the graphic for fuse ( kinda like a tilde ~ )
Whether or not its "safe" to use a carbon resistor in its place still remins to be seen, but......
on my controller PCB only the F1 is a blue body resistor, the other resistor for the LED (R1) is a standard old' tannish color.
On my friends BOTH are blue bodied (F1 and R1), so maybe its just a matter of what they had in stock at the time?? Or maybe one plant manager is a stickler for safety?
Both models are HKT3020's
Mine has the UD And Made in Japan in lower left of back tag, friends has WK and Made in China.
Yes they ARE fusable resistors, blue body does signify this and upon removal of the bad part, on the PCB it has the graphic for fuse ( kinda like a tilde ~ )
Whether or not its "safe" to use a carbon resistor in its place still remins to be seen, but......
on my controller PCB only the F1 is a blue body resistor, the other resistor for the LED (R1) is a standard old' tannish color.
On my friends BOTH are blue bodied (F1 and R1), so maybe its just a matter of what they had in stock at the time?? Or maybe one plant manager is a stickler for safety?
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TheDumbAss
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heh... well... I cant be blamed for not catching this.
I know little about the details in electronics. I didnt know there was such thing as a fuseable resistor. I thought batty0 was just dumb
The guys at the 3 radio shacks I checked when I went to replace my burnt out resistor didnt say anything about it. (well... they couldnt find it in any of their books eather) so I just went with the knowledge that was already avalible here.
2 10ohm resistors in parallel do work... I've been useing my dc with them for months. But they have blackened so I would recommend against them. (blackened = possible fire hazzard)
I know little about the details in electronics. I didnt know there was such thing as a fuseable resistor. I thought batty0 was just dumb
The guys at the 3 radio shacks I checked when I went to replace my burnt out resistor didnt say anything about it. (well... they couldnt find it in any of their books eather) so I just went with the knowledge that was already avalible here.
2 10ohm resistors in parallel do work... I've been useing my dc with them for months. But they have blackened so I would recommend against them. (blackened = possible fire hazzard)
My old Sig was broken. Enter the new Sig!
Use resettable fuses instead of fusible resistors....
I read a Usenet posting online that Sega is repairing controller boards with resettable fuses instead of fusible resistors.....resettable fuses act like fusible resistors, but when you remove the load they reset automatically. No more replacing the part.
These are relatively cheap from places like Mouser (http://www.mouser.com), but I don't know how to determine what the appropriate specs for a resettable fuse would be.....anyone?
These are relatively cheap from places like Mouser (http://www.mouser.com), but I don't know how to determine what the appropriate specs for a resettable fuse would be.....anyone?
TDA, I didnt mean to sound like I was blaming anyone. I hope I didnt come across that way. With regards to batty0, he did spam the boards a lot and his website is sketchy at best.
tikitom, I found that usenet thread. I didnt even know resettable fuses existed. Anyway here are some quick calcs, but please dont regard them as factual.
Fuses are rated by current (i.e. a 15 amp fuse). According to Ohm's Law:
current (amps) = the square root of (power (watts) / resistance (ohms))
Therefore if you decrease resistance, current should increase. Since the original resistor is rated at 3.9 ohm +/- 0.05 percent, the lowest acceptable value would be 3.705 ohm. We also know the original resistor is rated at 0.25 watts. Solving the equation above results in 0.259 amps. This should be close to the fuse rating.
This is the closest match I could find on on mouser.com
http://www.mouser.com/products/detail.c ... N=16074248
It trips at 0.34 amps and has an initial resistance of 3.30 ohm.
However, I have absolutley no idea if this would work as a replacement.
tikitom, I found that usenet thread. I didnt even know resettable fuses existed. Anyway here are some quick calcs, but please dont regard them as factual.
Fuses are rated by current (i.e. a 15 amp fuse). According to Ohm's Law:
current (amps) = the square root of (power (watts) / resistance (ohms))
Therefore if you decrease resistance, current should increase. Since the original resistor is rated at 3.9 ohm +/- 0.05 percent, the lowest acceptable value would be 3.705 ohm. We also know the original resistor is rated at 0.25 watts. Solving the equation above results in 0.259 amps. This should be close to the fuse rating.
This is the closest match I could find on on mouser.com
http://www.mouser.com/products/detail.c ... N=16074248
It trips at 0.34 amps and has an initial resistance of 3.30 ohm.
However, I have absolutley no idea if this would work as a replacement.