Dreamcast-Talk.com

kazade wrote:Welcome! You've hit a common problem which is a blown fuse on the controller board. I've documented how to fix it here:

http://blog.kazade.co.uk/p/dreamcast-co ... t-way.html

original resistor rf25scvtp0.39ohmk
0.25 watt 0.39 ohm
R=U/I and P=U*I
P=(I*R)*I
P=I²*R
I²=P/R
I=√P/R
I=√0.25/0.39=0,80064076902543566742
need fuse 0.8 A

another calculate, open manual for maple and look maximum current consumption
controller - 50 mA
VMU - 13 mA
vibro - 160mA
(50+13+160)*4=892 mA

megavolt85 wrote:

kazade wrote:Welcome! You've hit a common problem which is a blown fuse on the controller board. I've documented how to fix it here:

http://blog.kazade.co.uk/p/dreamcast-co ... t-way.html

original resistor rf25scvtp0.39ohmk
0.25 watt 0.39 ohm
R=U/I and P=U*I
P=(I*R)*I
P=I²*R
I²=P/R
I=√P/R
I=√0.25/0.39=0,80064076902543566742
need fuse 0.8 A

another calculate, open manual for maple and look maximum current consumption
controller - 50 mA
VMU - 13 mA
vibro - 160mA
(50+13+160)*4=892 mA

dreamcast i/o board fuse spec sheet pdf:
https://www.koaglobal.com/~/media/Files ... pdf/rf25cc

megavolt85 is right, but what is not being factored in is the 'slow blow' nature of both types of fuses.

the 72v 400mA polyfuse is the goto replacement part, despite being under-current to the original design. it is readily available. i've never heard of an issue in normal use cases.