This article was also published in the October 2010 issue of “Silicon Chip“, in the Serviceman’s Log.
Back when I was in secondary school I saved all pocket money to purchase a CD player that would allow me to blast out Led Zeppelin and Pink Floyd at the kind of volumes that would ensure my parents knew I was home. My choice of equipment: a Philips FW-380C mini hifi system.
Years past and the system went to university with me, where its auxiliary input made a great set of speakers for my computer. But somewhere along the way between then and now, the CD player stopped reading discs, and eventually it wouldn’t even power on.
Last year I tried to offload it at a car boot sale for $40, but no one wanted a stereo system that I couldn’t back with a working guarantee. Finally last weekend, whilst cleaning out the garage, I decided it was time to open it up and see if anything glaringly obvious stood out.
After removing several screws and disconnecting some cables, I could see an area on the main audio board that looked like it had been hit with an open flame! The fried components occupying this space included two resistors, four transistors, and a zener diode.
A little more searching, and I came across a large capacitor, 4700uf 35V, that looked as if it were glued to the PCB. I quickly realised the ‘glue’ was actually capacitor innards that were now outside of the capacitor.
A quick search through my very limited stock of components revealed I had a 4700uf 35V to replace the leaky one, but no resistors, transistors or a diode for the fried area of the audio board.
I decided I had nothing to lose – lets see what happens if I just replace the leaky capacitor. A quick once over with my soldering iron, and I was ready to power up. To my surprise, the CD carousel rotated around, and the system went into the store demo mode! It was alive again.
I switched to tuner mode, and tuned in the local radio station successfully. After some more tuning however, the system dropped out briefly, and went back to demo mode. Uh oh. I quickly tried the CD player, but for each of the three discs in the carousel the display said “No disc”.
I powered down and made the trip to Jaycar for parts. Two BC547B and two BC337 transistors and a couple of resistors were easy finds, however the zener diode, labelled BZV55F was a different story. The best I could find was an 1N751A (400mW, 5.1V) – it would have to do.
I proceeded to replace the four transistors and two resistors before trying again. This time I had more success – no drop outs back to demo mode, however still no CD playing. I could see the disc try and spin, but only manage a wobble before displaying “No disc”.
It had to be the zener, so it was next to be swapped. By now I was an expert at pulling the system apart and putting it back together, but even with the replacement zener diode, it was still displaying “No disc”.
A quick google of “philips hifi no disc” and the obvious hit me right in the face – a dirty lens. A quick cotton tip clean later and sure enough, the CD player was back in business. Sometimes the simplest of things are the least obvious!
I even decided it was worth parting with $6 to purchase a pack of replacement drive belts for the cracked and broken cassette deck belts. I will probably never use the decks, but the satisfaction of bringing my childhood ‘rock box’ back to life – complete with cassette decks – made me do it. Good times.




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