techknight
Well-known member
I am starting this thread because we are at the point where this needs done.
I also want a record for links to other peoples projects on that so they don't get lost. I know there is one floating out there, but alas... I forgot to save the link to it.
Anyways... I have a prototype M5120 and sure enough the hybrid is shot. And I am fresh out with no real way to fix it. first it was not wanting to turn on, etc... I was able to fix that but its stuck in charging mode which means the PMGR IC switches to a different ADC scale. so if the battery is about 6.1V or lower, it shuts off saying its too low, no reserve power. So basically the window comparator isnt latching. Could be the oscillator inside the IC, or it could be the reference comparison voltage has changed/drifted out of spec due to resistors changing in value. This is also dangerous for the battery, because the charging circuit will NOT shut off when it reaches full charge.
The trouble with the hybrid ICs is the cap juice gets into the ceramic substrate, and eats away/changes the laser etched carbon film resistors that they print onto the ceramic substrate. If those values change, it throws everything off, especially because there are analog voltage references, and resistor divider/feedback networks for the window comparator. Those resistors change in value, the whole thing is just screwed.
That one project I saw awhile back, the resistor values logged looked suspicious so I am going to say that his Hybrid is also bad and he has some bad resistor readings.
the Hybrid that was on this board, a 100K ohm pull-up resistor was reading about 86K after I pulled the hybrid out of circuit. and before I heated everything up, it was around 4K. So I know this is an issue.
So, curious. has anyone worked on this project yet? I dont want to do a whole bunch of work and re-invent the wheel if someone has already done this.
And, would anyone want to pick up the ball once the design is tested/complete, and make assembled PCBs? Also, how big is the demand? Just curious.
I also want a record for links to other peoples projects on that so they don't get lost. I know there is one floating out there, but alas... I forgot to save the link to it.
Anyways... I have a prototype M5120 and sure enough the hybrid is shot. And I am fresh out with no real way to fix it. first it was not wanting to turn on, etc... I was able to fix that but its stuck in charging mode which means the PMGR IC switches to a different ADC scale. so if the battery is about 6.1V or lower, it shuts off saying its too low, no reserve power. So basically the window comparator isnt latching. Could be the oscillator inside the IC, or it could be the reference comparison voltage has changed/drifted out of spec due to resistors changing in value. This is also dangerous for the battery, because the charging circuit will NOT shut off when it reaches full charge.
The trouble with the hybrid ICs is the cap juice gets into the ceramic substrate, and eats away/changes the laser etched carbon film resistors that they print onto the ceramic substrate. If those values change, it throws everything off, especially because there are analog voltage references, and resistor divider/feedback networks for the window comparator. Those resistors change in value, the whole thing is just screwed.
That one project I saw awhile back, the resistor values logged looked suspicious so I am going to say that his Hybrid is also bad and he has some bad resistor readings.
the Hybrid that was on this board, a 100K ohm pull-up resistor was reading about 86K after I pulled the hybrid out of circuit. and before I heated everything up, it was around 4K. So I know this is an issue.
So, curious. has anyone worked on this project yet? I dont want to do a whole bunch of work and re-invent the wheel if someone has already done this.
And, would anyone want to pick up the ball once the design is tested/complete, and make assembled PCBs? Also, how big is the demand? Just curious.
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