Motorola GP300 1 Hour Rapid Charger Repair ???

[Satelite]

Hello:
I have a motorola GP300 1 hr rapid chgr that appears to be dead but does show voltage on the contacts for battery.
Charger model number is HTN9630C
The wall wart puts out 20 volts dc so its good.
The voltage measurements on the chargers pins looking at the front of chgr and measureing the voltage on the pins is as follows.
This is the chgr with 4 slots but only 3 contacts.
Right pin 1 pos probe to neg probe on next pin right #2 is 18.2 volts dc .
Right pin 1 pos probe to neg probe on pin 3 is 11.6 volts dc.
Pin 2 to pin 3 shows minus 2 volts dc or 2 volts dc if switch probes around.
When you plug in the wall wart no led chg indicator at all and none when battery inserted.
I get the impression that the chgr might be working but no led indication possibly.
Don't have a run down batt to confirm this at the moment.
Is there any components that you have run into that could be at fault ?
Apreciate the help.
Satelite

[Will]

There is a series regulator in them that can go 'open'. 20 volts is too much for the regulator to handle. The are designed for 12 to 16 volts.

[Satelite]

Hello:
I am assuming from the schematics I just found that that is component U102 and from that info the charger is not long for this world being older and not as useful as it was for gp300 wide banders with narrow band being the norm today.
I appreciate the info .
Thank You
Satelite

PS: Anyone needing factory 12.5 narrow band GP300 UHF bds = I have 50 plus working bds from gp300 radios and these bds also fit the P110 radios.
These are 16ch factory narrow band boards .
Simply swap out your wide band bd and put in the narrow band bd and program.
These are for the 438 to 470 MHz band and I do have a few VHF 16ch narrow band bds also.
If interested pm me.