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philips cd350 read TOC only once

Hi all,

I found next to the dumpster an old Philips CD-350 player and since it looked good, I took it home, in my mind just for parts. I didn't expect a so old looking player to still work. Once home, the player had a couple of obvious faults: motor belt broken and some led segment not working on the display (that's strange, I've never seen led segment to go completely off, but I think there's no other explanation since the led digits are multiplexed and segments on other digits work just fine). Another fault that took me a while to identify is that the player appear to be able to read the TOC only once after power up. If I change the disc it remember the first TOC it read after power up no matter what I try. Other than that it sounds really good, I didn't remember I have listened to such good CD sound previously (listened just to the headphone output while it was on the bench, but still sounded kind of great really). Does anyone have a clue about the TOC reading problem anyway? Caddy's switches appear to work fine since the disc spins momentarily after the caddy loads. Still the new TOC isn't read (or stored?) if the player has already read one after power up. Of course with the wrong TOC the player still plays what he believes are the correct track begin times.

Thank you in advance

Frank IZ8DWF

Reply to
frank
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Not sure how similar the CD350 is to the CDM-3 Industrial player, but on that model (used in jukeboxes in the late 80s and early 90s) the player logic was separate from the player itself. If that is the case then your player is probably fine, you have to track this in the CD-Control logic.

I would expect to find a "Load" function - this should clear the TOC register as well as indicate somehow that the CD has been placed on the player - I would start there. Perhaps there is a microswitch or opto-switch that records that the CD disc clamp (to motor) is in place?

John :-#)#

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Reply to
John Robertson

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Check to see that the sled position switch is working properly. There shou= ld be a small leaf switch that is triggered when the optics are in the "hom= e" position. These can get corroded over time and not make good contact. = The unload/load process activates the tray and forces the sled to be in th= ehome position. It is possible that the extra "umpf" of the unload makes s= ufficient contact to allow the TOC to be read.

Another possibility is that the leaf switch has moved such that the optics = seem to be at TOC when they are not. Again the unload above will force the= optics to be in the mechanical home position which may be beyond the "elec= tronic" hoem position.

Dan

Reply to
dansabrservices

Just found the problem, three bad transistors (2 x BC338, 1 x BC328) on the display/keyboard PCB. They probably overheated and burned when the caddy movement belt broke. Now the player loads and unloads fine and of course still plays everything. Too bad the LED display is a custom one so I have to live with broken segments.

Sorry for using google but my new provider doesn't have a nntp server (any suggestion?)

Best regards Frank IZ8DWF

Reply to
IZ8DWF

I've seen (surfing the net) this display problem on most Philips CD players using that LED display. If I understand correctly, the display is just a shift register plus LED drivers, in one custom (and small) IC. The LEDs are surface mount. I didn't want to remove the LED cover and test the LEDs, I'm quite sure that the drivers died, not the LEDs. Did anyone ever try to remove the cover and check that? Building a replacement with discrete transistor drivers would be too big to fit the space. The only real option is using a small microcontroller and a modern LCD display... Not sure I'll ever find time for that :-)

Best regards

Frank IZ8DWF

Reply to
frank

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