Burnt ic chip on Korg microKorg pcb.

If you wish to get some details; check the site linked here. Pull up older posts. Surf the site with patience. http://electronicshelponline.blogspot.com/

Hello
Check the retifier diode for 5VDC for short. If it is OK, replace the regualtor IC [5VDC], if used.

The volume control must be have dirt in it. When you move it do you hear rustling noise. A quick spray of WD40 spray into the control will solve the problem.

For specialized hardware like this, it's best to contact the manufacturer directly.

Fuse probably went bad because either the large filer capacitors at the edge of the PCB went bad and or the final output IC mounted on the heatsink(15 pin) fried. Check the capacitors and all the semiconductor components on the board for burn marks or corrosion. You have to remove the heat sink clamp from in front of the output IC to adequately visualize its condition. In fact you might have to remove the large aluminum heatsink attached to the chassis to get a good view of the IC. If it or the heat sink clamp show signs of thermal burns you need to replace it. The IC is a TS TDA7294 mono audio amp available at Mouser Electronics. Replace the 35V 4700mF caps with 50V 4700mF caps. You will only have enough space on the top of the PCB for one of the larger caps. I mounted the other on the circuit side of the board. Note the polarity of the original caps and respect it in their replacements. The fuse is a 5 X 20 medium speed slow blow 250V 2.0A glass fuse.

Hello,

Transistors are with just three pins, so what you are seeing there should be an ic and not a transistor.

It is ics that have numerous pins, transistor have just three legs(pnp) or (npn).

So what you see is an ic.

Take care.

I have the Daewoo Plasma Digital Dream model dp-42sm and it had power but no picture and my dads tv expert friend looked at it said the ysus board was out. I got the part on ebay for 125 dollars with 12 dollar shipping and put it in myself very simple and the problem is fixed. Is this the same issue your having?

I can tell you what it is from first-hand experience. The audio in LED's coming on and going out means that a power supply putting out more than 9 volts DC was used...or the wrong polarity. Korg sells a repair manual for about $12 but they ultimately need a whole new circuit board. If the wrong polarity supply was used, then maybe only a diode was damaged. This would be a cheap fix. But more than likely it knocked out one of the large surface mount IC's that us techs don't even dare to replace. Korg charges around $280 for a new circuit board. A used working microKorg sells for this much.

Honestly, I would stay away from Korg products and many others. Many companies are now using surface mount components which are cheaper and harder to fix. Moog synths are expensive but they are completely fixable(and are built to last). If Korg would install a $0.25 voltage regulator on the input of the DC jacks, the unit would be saved. I think this pretty much sums up the build quality. This is probably not what you wanted to hear but is how it is unfortunately.

A diode or two could need replaced. I can't find a schematic. A microkorg would not be a fun project to take on yourself. Check this page and put your zip code in and check for a repair center (if you are in the US..I don't know if there is a repair center in Japan.

http://www.korg.com/SupportResults.aspx?productid=128

Hi Mate, I have the exact same problem, casued by wrong adaptor being connected by accident, did you manage to find what the code is on the IC5 chip ?, I can see NSV, but there is another letter or number before it but cant make it out as that where its burnt.