Imac g5 capacitor check

Hello forum

I have an imac g5 m9845ll/a. The gpu went on it. I relpaced the logic board however now i have some capacitors that do not work or find themselves poorly installed because the imac will turn on however the 3rd and 4th diagbostic leds will not turn on. How can I check a capacitor to see if it works?

Thanks

Kind regards

Jorge vidaurre

When the 1000uF and 1800uF electrolytic capacitors fail on the iMac G5's, the top of the capacitors bulge an often leak a small amount of brown electrolyte. They will not be poorly installed unless someone has previously replaced them and made a poor job of it. The capacitors are soldered into plated through holes and do not remove easily, so if original do not suffer from dry joints (cold solder). If you want to check the capacitors you will need to remove and check with an ESR meter. Basic info on ESR meters here http://www.condoraudio.com/wp-content/uploads/Reviews/How-to-Choose-an-ESR-meter.pdf. You can also build your own, I did mine. You can buy cap kits cheaper than sourcing individually, here is one example Apple iMac G5 Motherboard / Logic Board Capacitor Repair Kit - 17" & 20" 2nd Gen | eBay

If the capacitors are not bulging or oozing brown electrolyte, you realistically have another problem. Can you trust the source the the logic board you fitted? Did you fit it carefully and take ESD precautions?

Was this a new or used logic board?