Wednesday, June 14, 2017

Samsung HT-Z220 Home Theater System dead now repaired

This Samsung was brought to my workshop and the customer said that the set could no power on though the standby LED was on.
This problem was caused by electricity fault.
To confirm what the customer said I connected the set to power socket, for sure the standby LED on the power button was on though blinking.
This confirmed that the set could be having power problem.

I opened the set immediately did a visual inspection and thereafter did voltage test on the output pins. Fortunately the pins were labelled output voltage expected.

 I started with the 5volts, to my surprise the voltage kept fluctuating from 3 2 0. I tested the 33 volt supplying the amplifier and this voltage was enough and very steady. The other 12 volt required by the board for it to work wasn't available because the machine could not power on the power supply. I knew that for the machine to power on there must be steady 5 volts supply. Therefore I followed the 5 Volt backward and it took me to a surface mount i.c mark A0Z1021AIL

Marked IC501 on the circuit board

Luckily enough I got the power supply schematic from the internet and I was able to get the pin out for IC. I tested voltage on pin 2 of the IC and I got 0 volt.

Checking backward I found a rectifier diode marked DR5601 On the board. Testing it, it tested shorted there I am I thought at last I got the culprit. I de-soldered one pin to make sure that really it was shorted. To my surprise the diode was very much okay.

Now I was left with only one possibility the IC Mentioned above could be shorted. I removed it from the board and tested the diode again. This time round the short was no longer there. I tested the i.c vcc pin and ground pin and it tested shorted.

I had to start looking for this IC from electronic spare parts all over but it was all in vain. I tried it from my fellow technicians which was in vain. I consulted one of Samsung care center in Nairobi Kenya but even after the machine took 3 weeks with them they said that the ma-chine was out of market and therefore the spare part were no longer available. This spelled doom to my possibility of bringing back this machine to life.

No more hope for the machine. I talked to one Mr Humphery Mndaka asking him whether he could get me the said IC and he came up with one brilliant idea of ordering it online. Within two weeks I got a call from him that the IC had already arrived and I made arrangement on how to collect it.

I was very happy at last I have the IC, I couldn't wait to solder the IC. I tested the five volt supply and there was a steady 5 volts supply. This brought lot of hope. I connected back the power supply and the power LED was steady (not blinking). It was now time to power it on. Great!!! The machine is now kicking and working as new.
My regards to Mr. Humphrey for kindness and willingness to place the order on my behalf.

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