Cd spins like crazy

[Calamaro]

Playing with an old Philips cd player, usual mods (new capacitors, non oversampling...). Suddenly the cd starts to spin like crazy, it doesn't stop. Possibly it can read TOC anymore? What did I wrong?

 

[olriley]

You don't list player type or spec (not very helpful).

I assume its a tda1541/saa7220 family machine

No clock signal most likely. Otherwise faulty SAA7220. See here

Regards - Oliver

 

[Calamaro]

Oliver, thank you for your reply.
Player is a tda1543 based.
I haven't a scope so it's impossible to check clock signal I think.
I'll try to replace SAA7220.

 

[amc184]

Unless you've done something really strange, I doubt any particular part is faulty. Uncontrolled spinning of the CD means that the spindle motor control circuit isn't working, possibly due to a loss of clock to the SAA7210 / SAA7310 decoder IC.

What model of CD player are you using? What exact modifications did you do to the CD player? Can you post some photos of the CD player in it's current state?

 

[poynton]

Have you "modded" the clock ???

Possibly upset the clock signal when you did the NOS mod.

Sounds like you did all the mods at the same time !!!

RULE #1

One mod. at a time and check it is working before going to the next mod.!

Andy


.

 

[bernhardn]

Did you read this?

Laserology

 

[Calamaro]

Player is a Philips cd210.

Mods:
replaced filter capacitors/checked: ok
replaced opamps+bypass/checked: ok
non oversampling/checked: ok
connected 7805 regulator to main filter capacitor (with wires, my aim was to feed the dac)/checked: cd spins like crazy
removed 7805/checked: cd spins like crazy

 

[Extreme_Boky]

Before you connected the 7805 reg have you disconnected the original supply? This is a bit "tricky" - I hope you did it properly. I usually cut the track(s) and feed external supply as close as possible to section that needs it.
Also, have you connected the common of the 7805 to common on the PCB?

Boky

 

[Calamaro]

Boky, actually I didn't connected the reg to dac, I just soldered it (through wires) to main filter capacitor. Common of the 7805 connected with capacitor minus leg. Then I checked the player before feed the dac with the new supply and the cd started to rotate like a catherine wheel

 

[Technical]

Sounds like you have lost the clock signal.

I would first try "un-doing" the NOS mod. If that doesn't help and you have no scope, I would next replace the digital filter chip (7220, I think?) which I believe also has the clock oscillator on it.

Good luck!

 

[eschenborn]

SAA7220 dedicated +5V regulator chip wrong way – solved

Thanks to all contributors to this (old) discussion – and anyway the whole community here. The thread helped me solve a glitch that occurred when I did the dedicated SAA7220 power regulator mod for my Philips CD371 with TDA1541.

To do this this, I created a mini PCB which I soldered on wire stands into free wholes in the main PCB – I but placed the LM317T in the wrong direction. Then had the motor spinning like crazy... I wondered if I had broken the ribbon connector. thanks to this thread I could quickly find the fault.

I am not sure yet if I do hear any improvement with the new regulator (takes +9V from C2515) from the status as freshly recapped-uprated. I finished the recap yesterday and left anything else factory style.

eschenborn