Philips CD-650 recap/repair November, 2022
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A Philips CD-650, still working, I never used it since it always emitted some "hot-electronics-alike" smell, due to some electronic part not attached firmly to the heatsink.
I opened it up, the result was there is nothing special inside looking burnt. It appeared, one of the voltage regulators (7805) went hot.
Because of the 7805 and 7815 have no insulator, it was decided to measure if they did have electrical contact with the heatsink. The 7805 regulator did have a suspicious resistance (around 1 Ohms), so I concluded the now not that apparent smell could be caused by a poor thermal contact, also. The fact the mounting clip was a little loose made me more sure of this possibility.
Next thing to do was a "recap". Measuring some of the capacitors coming out, revealed almost ALL of the little axial Philips capacitors were seriously deteriorated, but all of the radial types looked still good. I decided to replace all of the electrolytic capacitors, good or not. BTW, the transport mechanism has one smoothing capacitor, which can be replaced without removing the circuit card, it is possible to access it sideways.
Empty cd player and the clip-mounted regulators.
The Philips cd650 main circuit cards.
There are two. One of them has almost all the normal cd electronics, but there is an additional one mounted.
It is a filter card, containing additional filtering, providing an extra output to an additional set of RCA connectors. I remember the fierce discussion between audiophiles back in those days, whether using this filter was sounding better, or not.
Apparently, Philips did see some added selling value, providing this extra filter.
Pictures of the filter card, before and after recapping.
The main circuit card, including the power supply, before and after recap. Observe, the power regulators are mounted using bolts, now. As before, the two positive output ones are mounted directly. The negative output regulator has a ceramic insulator now, instead of the old mica one.
The cd player front, before the recap.
The front has a package of three cards, which can be accessed keeping the connecting cables intact. It has an optical receiver, unfortunately, its remote control device I do not have.
Below the hidden "keypad"on the right, is the headphone output. Observe the consequent Philips design using high quality SFR type metal film resistors, the grey ones being inflammable. A sharp contrast compared to the axial capacitors, which are in so very poor shape in this player, it is remarkable it still worked.
Some cleaning.
Halfway the recap, I just decided do something some people consider not done, saying "it will never work, again."
The two separate circuit cards are getting a nice warm bath.
The refurbished CD player, it is alive and kicking.
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