Panasonic SA-BTT270 Repair

The repair of the SA-BTT270 is an extremely complicated and dangerous task as there are high voltages present. Therefore if your unit requires service, then you should have it repaired by a qualified service engineer. Being a seasoned and qualified engineer, this article simply shows what is involved and might be of interest to other qualified engineers.

I managed to locate all the replacement components on eBay and had them stored in my shopping trolley. I was just about to hit the Buy button when I had an awful thought. What if I spend £6.12 on all these components and it turns out that the switching regulator chip (IC5701) was faulty as well. For one thing, I do not know whether a replacement IC could be found, and I am sure it will not be as cheap as chips! However on the positive side, what if the replacement fixes the problem but the DVD drive turns out to be worn out and not reading discs... There was only one thing for it and that was to use recycled components to see.

Recycled SMD Components

I was glad I saved some pre-used SMD components as they came very handy. I had the zero-ohm link, and 220-Ω resistor, hence I installed them in first. I also found a recycled Dale R025F.

I decided to fit the R025F first as it had much less resistance and wattage rating. I figured that if the circuit had a short somewhere, then it will blow very quickly. However, when I switched ON the unit it was operating as if nothing had happened. Hence I decided to fit another resistor to the pads next to it. This resistor is 0.1-Ω and 1-watt rated and as you can see, I attached an insulating cover over it. Underneath it, I managed to slide in a recycled mica layer to provide insulation for added protection in case it heated.

When I installed the 0-ohm link, I tried to increase the distance between it and the high-voltage track next to it; hence it is at an angle. The 220-ohm resistor is the one next to it.

Repaired Board

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