Tuesday, July 6, 2010

BD7956FS implementation

Hi !

Just found some time to start writting down the schematic section for the BD7956FS interface.

I started with the spindle motor connector and I will add little by little the other stuff I identify !

This should help you to diagnosis and repair the sled / spindle / insert motor problems !

See the previous article like on the spindle motor board analysis for understanding.

TP stands for test point.

C5 is the 5V_2 power supply decoupling capacitor.
R4 is a pull up resistor to force the inactive state for the switch SW1 information.
R1/C4 is a filter to debounce the switch SW information that is send to the CPU.

All the other signal for the spindle are directly driven by the BD7956FS.

We can find the 3 PWM commands U,V and W, and the Hall sensing return signals for the motor controller.

Pins 35/40 : this goes to the BA5888FP, after looking at the datasheets this signal should be the Vcenter.

Pins 49/50/51 : after looking at the datasheet it looks like the power supplies for the sled section as noted SLVdd, SLRNF1 and SLRNF2.

These power supplies are filtered from the 12V_2 supply with the following RC filters R6/C10 and R5/C9.

Another power supply is generated from the 12V_2, it is filtered with the L1/C11 filter.

Added the Insert/Eject interface.

The motor control is simplier than the spindle as there are only 2 wires.

The optical flag is filtered with R7/C13 before going back on the PS3's main board using the 60 pins connector.

Several TP are placed on the various inputs of the Insert/eject board. They are grouped on the solder side into some kind of a test connector which must be used by SONY during the production tests to force test stimulis on these inputs.

Some of the NM (not mounted components on the Insert/Eject board) pins are attached to simple TP. But some and the SWx inputs are associated with a piece of design using several small components that I can't identify for now ! I'm having some reflexion on how I can have the schematic anyway. Maybe with some blackboxes ?

Any feedback is welcome !

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