
jjc
Hi! I picked up several Roomba Discovery 4200 series robots and have refurbed a few and got them running. They're remarkable little machines! I'm having trouble with two of them... they run fine on a full charge but the on-board charging system won't work. I tried connecting the charger directly to the unit (bypassing the dock/charging pad) without success. I do not get the slowly blinking red power light; nothing is lit. When docked, the two green lights are lit on the dock showing a connection but I get nothing on the Roomba itself. I did replace both the U2/U4 transistors but there was no change. There's obviously another problem with the on-board charging circuit. I'm trying to find a main board and charge port circuit diagram so I can attempt to troubleshoot it. Can anybody help? Thanks! *confused*
www.ez-robot.com/Community/Forum/posts.aspx?threadId=6470&page=1
Good luck!
mosfets: U2, U4 red part
I would start with a good battery after fixing the U2, U4.
PDF version:
charging_n_control_schema.pdf
Schematic source:
http://www.robotreviews.com/chat/viewtopic.php?t=4180
Info describing how the charging circuit works
http://www.robotreviews.com/chat/viewtopic.php?f=1&t=19083
Charging problem:
http://www.robotreviews.com/chat/viewtopic.php?f=1&t=19486&p=140023&hilit=not+charging#p140023
http://www.robotreviews.com/chat/viewtopic.php?f=1&t=19543&p=139971&hilit=not+charging#p139971
https://www.vic7767.com/is-it-my-roomba-or-my-battery/
If you get success please share your findings.
Good Luck ;-)