Hello Group.
I'm new here...drawing is attached that will help explain below-repaired traces highlighted yellow and thermistors are red:
I have a small project I'm working on..details:
Crown CST 4200A 4-channel 250W each. Original issue is the unit doesn't turn on. These have a typical issue with their 3-party low voltage PS going bad. I've had success with replacing them with a newer unit made by Mean Well.
I replaced the LVPS and repaired (jumpered) 2 burned-out traces that came from the power switch to the 1) power relay, 2)thermistor.
The unit now turns on but I get a blinking power light which means over/under voltage. I'm assuming over voltage because the 2 thermistors get extremely hot (enough to melt the hot glue off them). I immediately noticed it and turned the unit off. I pulled the LVPS out as-to not damage it, turned the unit back on and they still get very hot...obviously they're on the HV supply side.
There are (2) Y2-type caps in series for overcurrent protection. I pulled one and couldn't get a reading, assuming they're bad (would a 2200pf cap even register resistance on a multimeter?).
Without being able to power the unit up and test at the appropriate points, I'm kinda stabbing in the dark...
Any help/advice of what to check would be greatly appreciated.
Thanks-mohare
I'm new here...drawing is attached that will help explain below-repaired traces highlighted yellow and thermistors are red:
I have a small project I'm working on..details:
Crown CST 4200A 4-channel 250W each. Original issue is the unit doesn't turn on. These have a typical issue with their 3-party low voltage PS going bad. I've had success with replacing them with a newer unit made by Mean Well.
I replaced the LVPS and repaired (jumpered) 2 burned-out traces that came from the power switch to the 1) power relay, 2)thermistor.
The unit now turns on but I get a blinking power light which means over/under voltage. I'm assuming over voltage because the 2 thermistors get extremely hot (enough to melt the hot glue off them). I immediately noticed it and turned the unit off. I pulled the LVPS out as-to not damage it, turned the unit back on and they still get very hot...obviously they're on the HV supply side.
There are (2) Y2-type caps in series for overcurrent protection. I pulled one and couldn't get a reading, assuming they're bad (would a 2200pf cap even register resistance on a multimeter?).
Without being able to power the unit up and test at the appropriate points, I'm kinda stabbing in the dark...
Any help/advice of what to check would be greatly appreciated.
Thanks-mohare
