Question about main LED and F1 resistor

semicolo · Post by **semicolo** » Wed Aug 31, 2005 10:43 am

I found the posts on the french board talking about f1 if some of you speak french :
http://forum.aceboard.net/4752-1079-901 ... marage.htm

Also the colors on f1 seems to be
orange white gray gray green
(quite important that someone tells me since I'm colorblind

LyingWake · Post by **LyingWake** » Wed Aug 31, 2005 5:57 pm

On a working resistor, these are what the colors look like to me going from top to bottom:

Oragne
Blue
Yellow
Silver
Silver
Blue

BuddyJ · Post by **BuddyJ** » Thu Sep 01, 2005 12:58 am

Weird. On mine (PAL-E, Revision Number 1)
the colors are:
Brown
Orange
Black
Gold
as far as i can see it in the half-darkness

Edit: Changed yellow to Gold, last time I couldn't see it evry well...

LyingWake · Post by **LyingWake** » Thu Sep 01, 2005 1:35 am

Incase it matters, mine is an NTSC-U.

Alexvrb · Post by **Alexvrb** » Thu Sep 01, 2005 4:20 pm

They probably used random colors just to confuse you.

semicolo · Post by **semicolo** » Fri Sep 02, 2005 3:36 pm

I don't think that's random colors, I've seen in datasheets that constructors of fusing resistors seem to use different color codes

and so we have f1 with 4, 5, or 6 colors quite challenging !

I'm considering hooking a psu to a working f1 and blowing it by increasing intensity, but I don't have a good lab psu at hand for the moment.

Alexvrb · Post by **Alexvrb** » Sun Sep 04, 2005 5:45 pm

I wasn't being literal.

semicolo · Post by **semicolo** » Mon Sep 05, 2005 2:04 am

Do you know any other good method ?

Alexvrb · Post by **Alexvrb** » Tue Sep 06, 2005 10:53 pm

What? I was saying I was not being literal when I said they used random colors.

If you had really precise lab hardware you could find when it blows, yes. Or at least get close enough to get a suitable replacement.

semicolo · Post by **semicolo** » Wed Sep 07, 2005 6:43 am

Sorry I thought you were the one saying "blow it"

semicolo · Post by **semicolo** » Mon Sep 19, 2005 11:34 am

Assuming the readings are
orange white silver silver green
according to this page http://www.koaproducts.com/english/cata ... RF25_C.htm
those fusing resistors use a blue coating and a green color band for identification, this would give us
39 * 0.01 10% = 0,39ohms 1/4W
It can handle up to 800mA without blowing and more for short time, voltage drop at 0.8A = 0.3V so the 5V would read 4.7V for the controllers, which should be ok

This makes sense, I'm still searching other datasheets for the other f1 markings.

mikozero · Post by **mikozero** » Mon Sep 19, 2005 3:01 pm

nice work, keep it up

Alexvrb · Post by **Alexvrb** » Sun Sep 25, 2005 8:47 pm

Yeah, keep us posted if you dig up more.

semicolo · Post by **semicolo** » Wed Sep 28, 2005 11:40 am

I've seen other datasheets telling they use a fifth yellow ring to indicate fusing resistors.

could everybody post their color codes ? it's easy, just open the dreamcast and f1 can be seen.

semicolo · Post by **semicolo** » Thu Sep 29, 2005 7:43 am

those having an ohmmeter, take f1's value in the same time to be sure it's very low, below 1ohm.

semicolo · Post by **semicolo** » Sat Oct 01, 2005 8:51 am

My two dreamcasts have the 0,39 ohms resistors (orange white silver silver green).

LyingWake · Post by **LyingWake** » Sat Oct 01, 2005 1:21 pm

So, would it be safe to say (if there are any out there) that a 1 ohm resistor would be a pretty close replacement?

mikozero · Post by **mikozero** » Sat Oct 01, 2005 6:07 pm

you should be able to find 1/2 ohm resistors which would be closer,
but the thing is these won't blow when nesseccery,

it could maybe be better repaced by a fast acting mini fuse holder (or even a resettable mini breaker).

semicolo · Post by **semicolo** » Mon Oct 03, 2005 10:57 am

problem is we still don't know if these are 1/4W, 1/3W or 1/2W
safest bet is to use a 800mA fuse, but I would use a slow fuse, since fast acting won't allow short transients.