Cracked Power IC In Power Supply Identified

By Jestine Yong on April 21, 2015

The Conceptronic 90 Watt Universal Power Supply controller ic was completely blown up-identified

It was soldered to the bottom side of the pcb. But was not readable anymore because the plastic top was blown off. Luckily I did find the very small plastic top parts of this smd ic. But couldn’t photographit because it was just too small. (The chip left on the safe side is a 358 opamp). So I used my originally not for Windows 7 made Traveler USB Microscope. With build in Led lights and 10x, 60x up to 200x Zoom in.

This microscope I happily could update for Windows 7 by using the new USB driver from the internet. The driver is called: “Mikroskoptreiber Mod.I 2008 ZC-700W.exe”.

And instead of the originally enclosed VideoStudio 7 SE program from Ulead (no Windows 7 version), I use the pc program AVEO USB2.0 for PC camera to make snapshots or even video’s from broken parts. Mostly as in this case for reading the originally chip names from badly damaged and also burned parts. (See photo’s of this nice USB Microscope which is ideal for these kind of forensic investigations).

From the controller chip top only the characters LD could be determined. Everything else was blown away. But the 2 earlier mentioned little plastic top parts still weren’t lost and readable. The part name of this chip on the pcb was SU1.

From the photo’s below I managed to find out what the originally controller part was. A LD7575 !

Also the other blown parts are shown: A 20N60C3 Mosfet, and a C812 MURF 860 which is a 8A 600V special semiconductor from ON semiconductor (left pin is Cathode, right Anode). Both were isolated by some kind of teflon caps and with clamps attached to the Cooling Alu metal. (See next photo).

Above the now 2 unCapped and internally totally shorted Mosfet and special MURF860 Diode. On the left from them is the mounted optocoupler. Plus 2 resistors in front of them on the component side with an original value of 620 ohm (R1) and also a bigger 0.22 Ohm (R2) were defect (burn marks see next photo). And their values were also wrong now!

The Conceptronic pcb text was Model: FONY 9045 LED (4in1). DATE 2008-12-12.

I’m sure that after replacing all these parts, and the fuse of course, my power supply will work again. But since I do not have these parts at this moment I can’t show it.

But therefore I give this report in the meanwhile to show that also this very professional 90 Watt 12 to 24V Adjustable Power Supply with Deluxe Display and 5V USB 1AMP output from Conceptronic is completely repairable! (See next photo: the Top and Bottom of the professional looking housing).

And to conclude this repair some photo’s that show the PCB from all sides:

The two 3 pin standing black TO-220AB housed components are Dual 20 Amp High Voltage Barrier Rectifiers 150V. And the chip 8 DIL above the 2 Elco’s of 1000 uF 25 Volt, right of the Coil, is a 34063APT DC to DC 1,5 Amp max 40V adjustable converter control circuit.

The primary Fuse was a Fast 5 Amp (!!) 250 Volt glass type with soldered wires.

Another nice repair article to fix a very nice and also unique Conceptronic Power supply for universal use at Home!

Cheers !

Albert van Bemmelen, Weert, The Netherlands.

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