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-   -   philips cd350 read TOC only once (https://www.diybanter.com/electronics-repair/337875-philips-cd350-read-toc-only-once.html)

[email protected] March 26th 12 03:49 PM

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

John Robertson March 26th 12 06:36 PM

philips cd350 read TOC only once
 
wrote:
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


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 :-#)#
--
(Please post followups or tech enquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

[email protected] March 26th 12 07:15 PM

philips cd350 read TOC only once
 
On Monday, March 26, 2012 1:36:57 PM UTC-4, John Robertson wrote:
wrote:
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


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 :-#)#
--
(Please post followups or tech enquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."


Check to see that the sled position switch is working properly. There should be a small leaf switch that is triggered when the optics are in the "home" 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 thehome position. It is possible that the extra "umpf" of the unload makes sufficient 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 "electronic" hoem position.

Dan

IZ8DWF March 31st 12 05:22 PM

philips cd350 read TOC only once
 
On 26 Mar, 16:49, wrote:
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.


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


[email protected] April 12th 12 08:12 AM

philips cd350 read TOC only once
 
IZ8DWF wrote:

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.

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


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