OngCL wrote:My roomba is also not charging it's batteries. the power light showed "red" and been flashing for few day.
... but when pree on power switch, nothing happen.
... I had measured the power supply jack and is reading 22.63 VDC
but the Roomba battery connections (the 3 pin in the battery compartment) are showing 4.98 and 4.87 VDC with no battery connected.
You will have to do a more precise reporting of what points were measured to obtain those voltages. If any one of them happens to be between Batt(+) and Batt(-), your battery may not be usable.
Is this voltage indicate the charging circuit is good.
Can't answer that, because your data are unclear. In addition, most owners will not have electronic test equipment that permits them to make direct measurements on an active charging-controller circuit. I fall in that class, and I expect you do too.
You must then resort to indirect measurements / assessments
to determine whether the problem is with your internal controller, the battery, or with the power-supply. That 'indirect' tactic includes:
a) Battery is shown to charge via means separate from the suspect robot.
b) The charged battery is shown to power a load which simulates the load the robot would apply to it, and powers that load for an appreciable fraction of expected running time.
c) Battery's charging power-supply (viz, "APS Fast Charger") is shown to provide nominal charging voltage (which you have done), and supplies nominal charging current to a battery, or to a dummy-load.
d) When measurements and observations of (a) through (c) confirm those accessories are performing nominally, and you put that (known-good) battery into the robot; then connect the (known-good) charging power-supply directly to the robot and AC power it to begin the charging process, IF charging does not complete within a few hours it is fair to say: 'The robot's charging-controller is not working properly'.