Question about main LED and F1 resistor

LyingWake · Post by **LyingWake** » Sat Aug 13, 2005 5:07 pm

I've been reading some old topics in this fourm today. The other day when I went to do the main LED mod - I could get the LED to light up but it wasn't very bright. I wasn't really sure what the problem was so I figured the LED was bad (or didn't have high enough voltage) or I wasn't soldering the points in all that well.

Well, I read that somone had blown their resistor and was getting a low voltage from a multimeter, and once he replaced his resistor he was getting higher voltage.

Anyway, my F1 resistor is blown so I just did a quick fix by twisting it (this was about a year ago). I haven't had an LED on this Dreamcast for probably a year and a half so I don't know if the original LED gave the same problem.

You think that's why the LED isn't shinning very bright?

Smurph · Post by **Smurph** » Sat Aug 13, 2005 5:11 pm

What's the voltage rating of the LED you bought? it should be as close as you can get to 3.3v.

royhubbs · Post by **royhubbs** » Sat Aug 13, 2005 5:17 pm

I think its one he got from me, which were rated 3.3 - 3.6 volts...

LyingWake · Post by **LyingWake** » Sat Aug 13, 2005 5:22 pm

Yeah, they're the ones from royhubbs.

Smurph · Post by **Smurph** » Sat Aug 13, 2005 6:23 pm

I dunno then. Sorry.

dcmodder · Post by **dcmodder** » Sat Aug 13, 2005 7:10 pm

i dont see how the f1 could interfere with the main power led. they are in no way connected to one another... the only thing i can thing is to make sure that the legs of the led are making good contact, with the contacts where the old led was. if all else fails you can just run some wires from the psu. if u think about it it's basically the same thing. push the button the light comes on.

LyingWake · Post by **LyingWake** » Sat Aug 13, 2005 7:20 pm

dcmodder wrote:if all else fails you can just run some wires from the psu.

I didn't think about that. Once I connected the LED to the PSU, the LED would shine a lot brighter. I'm not going to hook it up like that, though. I'm gonna try to replace the resistor and see what happens from there.

EDIT: Also, on a side note: when I would connect the LED to the battery on the controller board, it would be as dim as when I hooked the LED up to the actually controller board. You think that has anything to do with the reason why the LED not bright either?

semicolo · Post by **semicolo** » Mon Aug 15, 2005 11:55 am

f1 is a fuse, you should replace it before you burn something (but I don't remember which rate it is)

dcmodder · Post by **dcmodder** » Mon Aug 15, 2005 12:22 pm

.05 if i remember correctly

LyingWake · Post by **LyingWake** » Mon Aug 15, 2005 1:23 pm

1 amp, 10 ohm resistor from what I've heard.

LyingWake · Post by **LyingWake** » Tue Aug 16, 2005 9:11 pm

I'm trying the replace the resistor right now with a working resistor from a spare controller port. It doesn't matter which way the resistor goes in, does it? Even if I did, I believe that I put it on the same way as it was when I removed the original one.

When I turn my DC on I get no audio or video output. The disc will spin up fine, and it actually looks and sounds like it's going to load and all that good stuff.

Beside a possible soldering error, what else could be the problem? I didn't get solder anywhere else beside the two points where the resistor goes.

semicolo · Post by **semicolo** » Wed Aug 17, 2005 12:07 pm

no the way doesn't matter.

There shouldn't be any relation between controller port and audio/video

that f1 should really be better documented
we have 10ohms 1amp resistor on one hand (very unlikely if you take the size of the object into account and the color codes)
50mA fuse on the other

LyingWake · Post by **LyingWake** » Wed Aug 17, 2005 1:06 pm

semicolo wrote:There shouldn't be any relation between controller port and audio/video

Maybe. But I don't think it was some odd conicidence. I didn't mess with anything besides the resistor. I'm going to go back to Radio Shack today and purchase some resistors and try those out and I'll report how those worked. I'm going to buy these resistors unless there's any reason not to.

mikozero · Post by **mikozero** » Wed Aug 17, 2005 2:00 pm

I've said the same thing loads of times, we sould write collectivly to SEGA and ask (seeing as it's designed to blow),
if we found the correct component out it may even be able to replace it with a miniature breaker mod,

i believe it's a fuse-resistor, a hybrid component.

i also believe that it's possibly of a different value in different regions (PAL etc)

it's definitely not (imo) a 100 or even 10 ohms resistor.

there's been loads of topics on this where people have said just buy a other one, which amazes me because, i don't know how people on a Dreancast site can think throwing away a DC when there not being made anymore is a good long term idea.

LyingWake · Post by **LyingWake** » Wed Aug 17, 2005 2:21 pm

So wait, I'm confused here. No one's exactly sure what type of resistor marked F1 the controller board uses? And by you saying you believe the resistor is a "fuse-resistor" are you saying the resistors I linked to may not work?

I don't think SEGA would even say anything about the resistor if you asked them. Here's their e-mail if you wanna bother e-mailing them: customerservice@sega-parts.com.

LyingWake · Post by **LyingWake** » Wed Aug 17, 2005 6:04 pm

Well I went to Radio Shack today and bought the resistors. After trying to put the newer resistors in TWO different controller ports I still get no audio or video. Though, I just looked at the website again and I ended up buying 1/2 watt - 5% tolerance resistors compared to the 1/4 watt resistors at the link I provided above. Both the ones I bought and the one at the Radio Shack website are "10k-Ohm" resistors.

It seems the the resistors I bought do not work for the controller port F1 resistor. Does any one know where I can purchase the correct resistors or rather the correct specifications of the resistor I need to buy?

semicolo · Post by **semicolo** » Wed Aug 17, 2005 7:36 pm

no 10kohms is way too much, in fact even 10ohms would make a significant drop of voltage to the controller port when used with very consuming peripherals.

LyingWake · Post by **LyingWake** » Wed Aug 17, 2005 8:02 pm

Alright, I guess those at the site are different since those are only 10 ohms. How many ohms do you suggest I look for since you say 10 ohms would drop voltage significatly?

crc73 · Post by **crc73** » Thu Aug 18, 2005 6:08 am

I'm not an electronics expert, but is it not a simple matter of putting a current through a known good F1, and seeing how it behaves, to determine exactly what it is.

You probably need some equipment other than a multimeter (an oscilliscope perhaps), but I would have thought it was a simple job for someone with a little basic electronic training.

But yeah, I agree with semicolo, someone here should have the knowledge to be able to better document *exactly* what it is.

(I remember some older PC mobo's had a component that looked like a resistor, but blew like a fuse - it was associated with the keyboard and mouse ports - the F1 is probably something similar).

semicolo · Post by **semicolo** » Thu Aug 18, 2005 12:04 pm

for example a 10ohms resistor would drop 3.3V to 2.3V at a current rate of 100mA (which isn't really much)