Hello..
I've got a old nice psu from my friend.
Acbel e2 power 470
But this psu rather weird, do something that i've never seen before.
This one automatically turn-on (without connect the green and black wire), after i plug the power cable to the wall.
Sooo.. there's no faulty in primary and secondary.. right?
For the first, i guess maybe faulty supervisor.
So i was replace the supervisor ic (wt7257) with the working one.
No good..
After i replace *ALL* the ic(s), transistors, 431, optocoupler, small caps near the supervisor ic, Even i was replace transformers (from working identical unit)..there's still same symptom.
Directly turn on after i plugged the power cable.
(diodes/ZD measured okay with multimeter)
* Primary uc3843 , tny277
* Secondary LM339, wt7257
I'm really lost here..
Any ideas?
Is the problem happened in primary or secondary side?
Thanks a lot.
I've got a old nice psu from my friend.
Acbel e2 power 470
But this psu rather weird, do something that i've never seen before.
This one automatically turn-on (without connect the green and black wire), after i plug the power cable to the wall.
Sooo.. there's no faulty in primary and secondary.. right?
For the first, i guess maybe faulty supervisor.
So i was replace the supervisor ic (wt7257) with the working one.
No good..
After i replace *ALL* the ic(s), transistors, 431, optocoupler, small caps near the supervisor ic, Even i was replace transformers (from working identical unit)..there's still same symptom.
Directly turn on after i plugged the power cable.
(diodes/ZD measured okay with multimeter)
* Primary uc3843 , tny277
* Secondary LM339, wt7257
I'm really lost here..
Any ideas?
Is the problem happened in primary or secondary side?
Thanks a lot.
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