I am trying to fix this 24Vcc swich power supply that has no output voltage. The problem might be in the PWM controller, however, I haven't been able to find the datasheet for this PWM IC tiny controller. Any idea?
(I am attaching some pictures for a better understanding of my troubleshooting)
Tracking the PCB:
GND pin 1
Feedback pin 2
RI pin 3 (100k between pin and hot ground).
Sense pin 4 (470ohm to source)
Vdd is pin 5
Gate pin 6
Maybe it's just an OB2262/ OB2263MP (or could be replaced by these ones). Pinout seems the same.
When I am plugin it the PCB (as it's like in the picture), Vdd starts increasing and get's stable at about 79V!!!! Vdd cap hasn't exploded yet, but it's rated 50V. This seems so much for a PWM controller..............what's might wrong there?
Between R1 and R2 there are 3M ohm (in the middle point 1.5Mohm), then it goes R3 with 200k...........at this point there is Vdd entrance...........also connected to the cap, diode and then hot earth..........that high voltage on Vdd is because IC is not installed?
Also.......all this bunch of resistors are connected in the AC entrance............before the rectifier. Not as in the OB2262 schematics.
Lost in translation.......trying to understand :-)
Regards,
Francesc.
(I am attaching some pictures for a better understanding of my troubleshooting)
Tracking the PCB:
GND pin 1
Feedback pin 2
RI pin 3 (100k between pin and hot ground).
Sense pin 4 (470ohm to source)
Vdd is pin 5
Gate pin 6
Maybe it's just an OB2262/ OB2263MP (or could be replaced by these ones). Pinout seems the same.
When I am plugin it the PCB (as it's like in the picture), Vdd starts increasing and get's stable at about 79V!!!! Vdd cap hasn't exploded yet, but it's rated 50V. This seems so much for a PWM controller..............what's might wrong there?
Between R1 and R2 there are 3M ohm (in the middle point 1.5Mohm), then it goes R3 with 200k...........at this point there is Vdd entrance...........also connected to the cap, diode and then hot earth..........that high voltage on Vdd is because IC is not installed?
Also.......all this bunch of resistors are connected in the AC entrance............before the rectifier. Not as in the OB2262 schematics.
Lost in translation.......trying to understand :-)
Regards,
Francesc.
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