Sentey ATX PSU - ERP650-PS - Trying to find out the right Standby IC

[temyth]

Greetings! I have this ERP650-PS atx power supply, it is a relatively simple psu, the primary has a driver IC that controls the two main mosfets (two 20n60S5), together with a Classic Standby circuit with a PWM IC (not a FET like the VIper22A) , relatively similar to the SDC606P.

The whole point is that I got this power supply years ago when I had no knowledge, apparently the PWM IC was burned because someone turned the power supply on with the switch at 110v in a 220v network (classic error). Important detail: the power supply at the time came without the primary capacitors.

At the time I put a pair of 680UF 200v capacitors(the power supply doesn't have PFC, it's just a pair of capacitors in series, classic) and replaced the old IC (which I threw away) with an SDC606P.

Currently with the SDC606P the psu gives a Standby signal but with an overvoltage (7v instead of 5v). When observing the circuit I noticed that one of the NC pins on the SDC606P is used in this source, which indicates that the SDC606P cannot be used on this occasion (which explains why of the overvoltage).

Now what intrigues me is how I will find out which IC is the right one for this circuit. I'm looking for help on how to accomplish this...

Some photos of the PSU are attached to help you find more information about it. I've looked for photos and diagrams of the power supply on the internet, but I haven't found anything about this model. I also looked for similar circuits in my scrap sources and didn't find any that used a similar schematic.

Att: I looked at the topology of the system with a little bit more of attention and i saw that Pin 4 of stdby IC is not connected to anything, with matches with the SDC606. Pin 5 is the feedback and pin 3 is GND, which all matches with the SDC606, i think that is probably the SDC606 the right one, i'm going to buy one and test (quite of difficult to buy eletronic parts here in Brazil so it is probably going to take a while).

[прямо]

If the SDC606P works under load at 7V standby voltage, why not change the TL431 voltage divider resistor to get it to output 5V?

[temyth]

If the SDC606P works under load at 7V standby voltage, why not change the TL431 voltage divider resistor to get it to output 5V?

Sorry, i may didn't explained pretty well, the SDC 606P doesnt work under load in the current conditions. With the SDC606P the PSU starts and stabilishs at 5v stdby, but 12v is high with 13v, and when i put load in the PSU it just turns down as if it didnt had enough current to power the system under load. As the SDC606P feeds the voltage controller that feeds the primary by the optoacoplators it makes sense to it doesnt work under load.

[Francesc V.]

Yeap..........I made same mistake while ago. SDC606 and SDC606P have a different pinout. Now I have both of them.

Let's see how it goes when you get the "right" one.