My Schumacher SS-51A-PE 10A Charger does not have any output voltage. Waited on cb to reset but still not working (never heard any click indicating that cb tipped)

It measures the voltage and when it is above a given value, maybe 12.2V it shows the alternator is charging.

Probably not worth repairing. Meaning, the cost to repair will most likely exceed the value of the charger.

use a voltmeter. turn on unit to a low setting, place volt meter leads on broken wires one on each. if the voltage goes positive on meter. the positive clamp goes on the wire that the positive(red) voltmeter lead is on and the same for the negative.
Good luck

If a battery is defective, it will not accept a charge and it is not the fault of the charger. When connected and switched on, with the clamps making solid contact, the amp meter should give you a reading, depending on the state of the battery. To do a quick test on the charger, try it across a headlamp bulb, The bulb should light and the amp meter should read about 5 amps.

Since the unit is foreign made, you're going to struggle getting an exact replacement - especially size wise.
I see that Amazon lists the item at under $50, so is it even worth the trouble of searching for one ?
You could always fit a generic replacement, that has a 10A current indication scale, but be prepared to make a minor modification or two to get the replacement meter to fit nicely.
Your local electronics store should be able to assist you in selecting a replacement meter that is closest in size.
Connection is a simple process.

Quite simply - the unit has suffered component failure - most likely more than one. Capacitors are the usual source of noisy 'bang' or 'pop' sounds, followed by diodes and bridge rectifiers. If you have some knowledge of electronics, you can attempt repair, but, if none, I suggest leaving possible repairs to someone who does.
The humming sound you hear is the transformer under stress, and, if left connected, it too will die.

Ah, I see, it seems what you have is a power pack. If so it would contain a gelcell battery, probably 12 volts. If this is true, then you may charge it with any 14-16 volt wall charger. You have to make sure you observe correct voltage and correct polarity when connecting up. Also you may have to obtain and change the plug on the charger wire.
I'm assuming the battery DC output is inverted to AC and you use it to power small AC appliances.

You are charging. The meter corresponds to the level of charge in the battery. Try setting to 10 A for 4 hours, battery should be half-way up. To determine if battery id dead.. leave battery off charger once it is fully charged...test with a voltmeter after 10 min.....battery should still be above 12v...after1 hour it should still be above 12v...if not battery is spent.

I’m happy to assist further over the phone at https://www.6ya.com/expert/robert_aad3edb7dfa380b9

Soo sorry, unit is DEAD.

I’m happy to assist further over the phone at https://www.6ya.com/expert/robert_aad3edb7dfa380b9