On April 12, 2021 at 21:29, Brad Humphrey said...
Looking the boards over, it might be something obvious. Like a blown cap, charred IC, etc. If you don't have any schematics to go by and/or experience with repairing electronics; then you can just try doing the board swap thing.
I find that a very critical visual inspection is worth hours of troubleshooting.
I hate it, but investing a few hours troubleshooting a unit that you've never seen before is more expensive than simply replacing a board, but may not be as intellectually satisfying.
A given model usually fails in a specific pattern that can vary with age (infant, mid and late life) If you are a recognized (by the manufacturer) repair station there are often very helpful bulletins. In some cases when I've recognized a particular model on the street, headed toward the store, I already knew what was wrong, I did not need to interact with the customer.
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I have a friend who worked as a field engineer repairing corporate computers. Knowing the model in advance allowed him to have a kit of boards on hand. He could swap a board and have the customer up and running very quickly. These field engineers were graduate engineers, not some kid with an SUV full of boards. The board would go back to a central repair shop for repair. The shop was very familiar with that board. After repair the board would be returned to the replacement pool. If the board failed again, it was crushed.
I wish that we could do this in consumer electronics. Unfortunately, relatively few units are setup for quick board swap, desktop computers are one of the few exceptions. There are too many models for a small shop to have a reasonable supply of boards and a tech may not know the models involved until arriving on site. (and the customer may not have correctly identified which unit is at fault) The consumer can be part of the problem too because they become married to a particular serial number and replacing a unit would not usually be satisfactory because the replacement might have a visual difference or imperfection here'n there.
How many years should a company stock boards for model XYZ? Some jurisdictions tax inventory. Even if it's only a warehouse space consideration, it's hard to justify stocking something that may not be needed for 8-10 years. An added insult after stocking for 8-10 years is that the consumer may not want to repair the unit and that board will never be sold. The price of replacement boards must take this into account. (along with handling) This is why a replacement board sells for many times the manufacturing cost.
Another difference is that a business contracts for a service, not a serial number.
