View Full Version : Need help on the wiring of an old MR01 board

2011.02.02, 02:22 PM

I badly need your help on identifying the wiring connections for my old MR01 board that I want to use on a project.

when I dismattled this thing years ago, I forgot to label the wirings. Where does these contact goes to - P1, P2, P3, P4, P5 and P6?

Why is it that it seem to have only two contacts for the servo pot (which is normally three)?

Which one is for the contact for battery ground (negative)?

I also notice that there is a "blob" of soldering lead on one side of the FET of the servo motor. I removed mine, do I need to re-blob it?
(this image came from another website)

(this is the image of my MR01 board)

I am asking this stupid question because I was so OC I removed the blob. Then when I tried to check with my mulitimeter, these FET prongs' are actually conected to each other anyway (on the board).... so I couldn't comprehend what is the need for that "blob" of soldering lead?! :)

Digitalis West
2011.02.02, 03:34 PM
P1 and P2 are the on/off switch. P3 is V+. P4 is V-. If I remember correctly P5 and P6 are the sense pot for the steering servo. Again... if I remember correctly, the solder blobs on those bottom fets once connected the steering servo motor. Not sure of the polarity on the servo stuff....

2011.02.02, 04:16 PM
thanks a lot Digitalis West.... if I may clarify... P5 and P6 are for the pot, what happens to the third pole of the pot - do I ground it to the middle pole?

Digitalis West
2011.02.02, 05:41 PM
Man it has been a long time since I have opened my MR-01.... The middle connection on the pot should be the wiper. One wire should connect to the middle connection, one wire to one of the end connections... which one??? unfortunately, I dont remember.... the third connection should be left open.

2011.02.03, 12:35 AM
hi wildthing...

from this picture...

upper right
orange & green wire... goes to the pot (there are only two) one wire connects two nodes on the pot while the other wire is connected to the third node...

the two white wires are connected to the power switch

the red and black wire is connected to the battery terminals on the chassis...

from this picture...

there's supposed to be a wire connected to each fet, one red one black... this in turn is connected to the servo motor...

they are soldered onto a ''blob'' of solder (as you mentioned) to two ''legs'' of the fets...

my guess is that it'll hold better compared to the wire being soldered onto one ''leg''

hope this helps... :D

2011.02.03, 02:40 AM

another clarification - the potentiometer normally have three poles... since two wires are used (orange and green)... which of them goes to the center and one side - is it the orange or is it the green?

2011.02.03, 04:15 AM
orange... :D

2011.02.03, 02:17 PM
thanks a lot dude

2011.02.03, 10:16 PM
no worries and good luck on your project... :D
don't forget to post pics too... :D