Allied 500Watt PC Power supply repair. Model Al-B500E



My Allied 500Watt PC Power supply, Model Al-B500E would not power back on. As is many times the case a secondary smoothing capacitor, C27 , had gone very leaky. As most of the capacitors in the power supply were the same make, G-Luxon I replaced them all with decent Japanese capacitors from Mouser.com.
Ideally, to perform this repair you would use a good high temperature soldering iron,(hot enough to remove the heatsinks), a good solder sucker and desoldering braid. Alternatively, if they still exist, a TV repair shop should fix this easily.
I repaired this power supply around 5/2009 the system has rab 24/7 since that day without issue!


Note: The primary side of a switch mode power supply will have potential lethal voltages when running, and that big smoothing capacitor can hold a nasty bite for a while after it is powered off.



Secondary Capacitors
 C22,C23,C25,C28 3300uF 10V 105
 C27 3300uF 16V 105
 C29,C32 470uF 16V 105


Primary Capacitors
 C6 2.2uF 50V 105
 C5 2.2uF 50V 105
 C8 22uF 50V 105






Board stripped of heatsinks and capacitors


Recapped, ready to have heatsinks replaced


Back in place.