Hi guys,
I am trying to troubleshoot a switch mode power supply which keeps cycling, the output voltage jumps around. The model of the power supply is ASTEC LPT42 - https://datasheet.octopart.com/LPT42-Artesyn-datasheet-8318749.pdf
Its a power supply based around the IC AS3842. I looked for any faulty components on the secondary side bulged caps etc. Couldn’t find any obvious faults. Following is the result of voltage measurement I took at the control IC
COMP = 0V
VFB = 0V
ISENSE = 0.260V Varies
RT/CT = 0.02V
GND = 0V
OUT = 0V
VCC = 11V to 18V keeps varying a lot
VREG = 0.08V
The power supply keeps trying to start up, voltage measured across the main filter cap also varies slightly during the failed start ups.
I was hoping that you could give me some more ideas on what to look for.
Thanks in advance for the help.
I am trying to troubleshoot a switch mode power supply which keeps cycling, the output voltage jumps around. The model of the power supply is ASTEC LPT42 - https://datasheet.octopart.com/LPT42-Artesyn-datasheet-8318749.pdf
Its a power supply based around the IC AS3842. I looked for any faulty components on the secondary side bulged caps etc. Couldn’t find any obvious faults. Following is the result of voltage measurement I took at the control IC
COMP = 0V
VFB = 0V
ISENSE = 0.260V Varies
RT/CT = 0.02V
GND = 0V
OUT = 0V
VCC = 11V to 18V keeps varying a lot
VREG = 0.08V
The power supply keeps trying to start up, voltage measured across the main filter cap also varies slightly during the failed start ups.
I was hoping that you could give me some more ideas on what to look for.
Thanks in advance for the help.