Preston Electronics, LLC


Declined estimate exception:

If the customer requires a detailed estimate for a high-power discrete amplifier, (especially if it is blowing fuses) the estimate fee will be $100, which will be applied to the repair if the estimate is approved by the customer. This is because an accurate estimate requires extensive testing and diagnosis to identify all of the damaged parts in such amplifiers.

Generally, when a high-power discrete amplifier blows the fuse, it is because there are shorted transistors in the output section of the amplifier. Usually these transistors were damaged because of the failure of one or more other parts in the preceding circuits. Finding all the damaged parts can take lots of time. Finding the bad parts is 90% of the work involved in repairing electronic equipment. (See 'About estimates'.)

As a rule of thumb, such repairs run approximately $200 - $300, depending on the output power rating of the amp. This assumes only one channel is damaged. Without extensive diagnosis, this is the best estimate that can be given. Of course, if the problem turns out to be much simpler, the bill will be less.