My parents found this 40″? or so, very new LED backlit monitor in a dumpster and reported it as inop with constant reboots. I immediately expected bad electrolytics and was not surprised in the slightest to find a pair of CapXons one of which was bulging.
These are 33uF 200V and were in parallel. I didn’t bother reverse engineering the power supply for this thing, but this appears to be the output capacitance for a high voltage DC rail that judging by the lack of other nearby caps represents most of the supply’s power output, likely powering the LED backlight and being converted to some number of other voltages elsewhere in the unit. Anyway, the non-puffed cap was a totally open circuit, whereas puffed cap returned 14uF and likely had sky high ESR. Replaced them with two 47uF 12,000 hour@105C Nichicons.
Of note is that these are a 12.5mmOD, something like 14mm length. I couldn’t even find anything 200V rated higher than 27uF in that form factor on digikey… Pretty sure CapXon is cheating a bit. What went back are 12.5x20mm which fit into the application without mods and most likely doubled or more the ripple current rating. This should not croak again anytime soon.
My parents found this 40″? or so, very new LED backlit monitor in a dumpster and reported it as inop with constant reboots. I immediately expected bad electrolytics and was not surprised in the slightest to find a pair of CapXons one of which was bulging.
These are 33uF 200V and were in parallel. I didn’t bother reverse engineering the power supply for this thing, but this appears to be the output capacitance for a high voltage DC rail that judging by the lack of other nearby caps represents most of the supply’s power output, likely powering the LED backlight and being converted to some number of other voltages elsewhere in the unit. Anyway, the non-puffed cap was a totally open circuit, whereas puffed cap returned 14uF and likely had sky high ESR. Replaced them with two 47uF 12,000 hour@105C Nichicons.
Of note is that these are a 12.5mmOD, something like 14mm length. I couldn’t even find anything 200V rated higher than 27uF in that form factor on digikey… Pretty sure CapXon is cheating a bit. What went back are 12.5x20mm which fit into the application without mods and most likely doubled or more the ripple current rating. This should not croak again anytime soon.
did those 33uf CapXon electrolytic caps suddenly start leaking or something? they don’t look buldged or burnt