Rotel RCD-955AX - Spinning backwards at full speed.

Passmore

Member
2018-12-06 5:26 pm
Hey folks,

Weird problem with this rotel. It originally had a problem where it would briefly spin backwards, and then show 'error'. I tracked the problem down to two transistors - T102 & T103 respectively. These are BC338 and BC328. I replaced them and now I have a different problem. It spins relentlessly, as soon as the unit is turned on! the motor spins at full speed backwards, and if i leave it on for long enough i start seeing smoke, though i can't figure out where from.

Anyone got any ideas? Thanks in advance.
 
The "spinning backwards" is a fault of the reading system, and I doubt that those transistors are the issue, but what is driving them would be of more concern.
They are likely "digital transistors", and you should test them appropriately, not as a standard transistor would be checked.
The average CD player uses a complex system of checks in order to read and play, something that if you're not familier with, you'll be forever putzing with.


Best to start with focusing on the error code displayed, then go from there.
 
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Passmore

Member
2018-12-06 5:26 pm
There's no error code displayed, it just says 'error'. The fault only started happening after i replaced those transistors though, and they were DEFINITELY fried before i replaced them. It makes me think that whatever is making the cd spin backwards at full speed fried the original transistors?
 

Extreme_Boky

Member
2003-12-07 11:57 am
Hey folks,

Weird problem with this rotel. It originally had a problem where it would briefly spin backwards, and then show 'error'. I tracked the problem down to two transistors - T102 & T103 respectively. These are BC338 and BC328. I replaced them and now I have a different problem. It spins relentlessly, as soon as the unit is turned on! the motor spins at full speed backwards, and if i leave it on for long enough i start seeing smoke, though i can't figure out where from.

Anyone got any ideas? Thanks in advance.

Check the 4MHz ceramic resonator X102. They fail quite often... U109 must have the oscillator working properly for its CPU to work, i.e. U109 pin 38 and pin 39 should have a 4MHz sinewave signal present.