Keefykeep
Novice Member
Hi
I found the fault with the PV1 i am repairing
It turned out to be the 470uF 16V capacitor (labeled C824), the ESR of this cap was over 20 ohms! (it was meant to be less than 1 ohm when new)
Why did it fail? probably because they used low temp, short life span SMG branded caps (85 degreesC at 2,000 hours) and it is close to other components that get quite hot, there is even a slight bit of heat caused discoloration on the small 2.2 ohm resistor (labeled R818)
I also tested the ESR of all the other SMG caps and they are also have higher ESR values above what they should be when new, but probably not out of spec enough to cause problems (yet)
The big brown nippon caps all measured low ESRs and are 105 degrees C rated
If you intend to measure the ESRs of the caps dont forget to discharge them via a resistor beforehand
I replaced the faulty cap with a higher operating temp longer life cap
Here is a link to an informative site about capacitors
If this cap replacement does not work for you, then check for dry solder joints, and also if needed, get a component tester (ie, Multi function Tester TC1 ) to test other components like semiconductors etc
+1 for the hair dryer tip,
cheers, and good luck
AND REMEMBER BE CAREFUL OF THE HIGH VOLTAGES THAT ARE PRESENT ON THIS EQUIPMENT!!
Read the safety first comment on this following link before working on the SMPS power board of the PV1
Troubleshooting switch mode power supplies
I found the fault with the PV1 i am repairing
It turned out to be the 470uF 16V capacitor (labeled C824), the ESR of this cap was over 20 ohms! (it was meant to be less than 1 ohm when new)
Why did it fail? probably because they used low temp, short life span SMG branded caps (85 degreesC at 2,000 hours) and it is close to other components that get quite hot, there is even a slight bit of heat caused discoloration on the small 2.2 ohm resistor (labeled R818)
I also tested the ESR of all the other SMG caps and they are also have higher ESR values above what they should be when new, but probably not out of spec enough to cause problems (yet)
The big brown nippon caps all measured low ESRs and are 105 degrees C rated
If you intend to measure the ESRs of the caps dont forget to discharge them via a resistor beforehand
I replaced the faulty cap with a higher operating temp longer life cap
Here is a link to an informative site about capacitors
If this cap replacement does not work for you, then check for dry solder joints, and also if needed, get a component tester (ie, Multi function Tester TC1 ) to test other components like semiconductors etc
+1 for the hair dryer tip,
cheers, and good luck
AND REMEMBER BE CAREFUL OF THE HIGH VOLTAGES THAT ARE PRESENT ON THIS EQUIPMENT!!
Read the safety first comment on this following link before working on the SMPS power board of the PV1
Troubleshooting switch mode power supplies