This cheap and quite frankly nasty DVD player came in as a dud unit. No lights on, nothing. To be frank, not even I thought it would cost in to repair it, since the owner told me it didn’t cost more than £20 in the first place.
Never mind, off with the cover and a quick poke around with the multi-meter revealed no power coming from the transformer within the unit. This converts high voltage from the mains to lower, safer voltages for the player. On this DVD player and many others I’m sure, the internal processes are broken up in to ‘cards’. On this unit, there’s a power card, a logic card for the motor drive and a video card for the picture. Closer inspection of the (cheap and horrible) power card revealed several faulty components, which had failed catastrophically. At first glance, I suspected that the cost of replacing individual components wouldn’t cost in and that sadly, this DVD player might be headed for the bin.
Fear not! With the power of Amazon, I was able to find a generic suitable DVD power card via China that fitted, with a small amount of wiring for £5, delivered. Job done.
For those wondering what an ‘inverter’ is, let me give a quick explanation: It allows one to use a mains operated device on the move, using a power supply from a motor-home, car or boat, as an example. An inverter ‘inverts’ a smaller voltage to a larger one, usually for most applications. Most inverters sold turn either 12 or 24VDC to 240VAC or 110VAC.
The owner of this one had accidentally connected the input wires the wrong way around, effectively reversing the polarity. Not good. Upon hearing a little ‘pop’ the owner quickly disconnected the power!
Having never worked on an inverter before, I turned to the manufacturer for advice. Sterling Power (UK) were not able to supply any product information on the phone nor via email and were generally not very helpful at all. They did offer a very reasonable 25% discount on a replacement, but were not able to offer much else to save the one I had in the workshop. Never mind.
Back to the problem. Checking the basics, the ‘accident’ had appeared to knocked-out three 25A soldered PCB fuses. Temporarily by-passing the fuses revealed a working unit, so replacing the defective fuses was a good idea at a very reasonable £1.50.
The fuses are mini-blade 25A automotive fuses. Once removed and the new ones soldered in place, the unit worked once more.
Cost of parts, £1.50, cost of replacement unit, circa £160.00.