Philips CDI 205 Troubleshooting Guide

Front and rear of the CDI 205 from the service manual. Port 1, used to start the service shell, is socket 10 on the front; port 2, used for the low-level test, is socket 14 on the rear.

Philips's service manual for the Philips CDI 205 treats the player in sections: the power supply, the MMC (Multi Media Controller) board, the CD part and audio, and the video encoder. Its advice is that the CD servo and audio sections can be fault-found like any CD player, while the MMC board is diagnosed with two built-in programs, the service shell and the low-level test, and replaced as a unit if it is faulty. Everything else can be repaired to component level. Dismantling is described on the Philips CDI 205 General Maintenance page.

Symptoms and first checks

Common symptoms

Symptom	Likely cause	First check
Dead, mains fuse 1001 blown	Shorted switching transistor 7002	Check 7002, then 7001 and 7004
Power supply squeals	Short on the secondary side or in the player, or the overvoltage protection has tripped (7007 runs hot)	Unplug the loads and test the supply on the bench with a load resistor (see below)
Tray will not open, no open icon on screen	Shop demonstration mode	See below
Settings and clock lost, light blue screen, "memory full"	Flat Timekeeper NVRAM	See below
Player shell does not appear	MMC board or its supplies and clocks	Run the low-level test; if it will not start, check the MMC supplies and clocks
Disc does not start	CD drive processor, X-bus or SPI bus, servo	See disc faults
Picture but no sound	Audio path on the APU or CD panel	See audio faults
No picture, no colour, or player shell but no disc video	Video encoder panel or MMC video decoding	See video faults

Built-in test software

Service shell

The service shell has tests for the video circuits (a colour bar pattern), the CD mechanism and servo, the input and output ports and the audio circuits. The CD, servo and audio tests work only with an audio CD (CD-DA) in the drawer. To start it, link the RXD and TXD lines of port 1 on the front (pins 2 and 3) during start-up: fit a test plug before switching on or resetting the player. Menu boxes are picked with the pointer and a button on the remote control, and error messages appear in a box at the top of the screen. If the shell will not start with the plug fitted, the plug may be wrong, the connection between port 1 and the slave processor may be broken or the slave processor may be faulty; Philips's advice is then to run the low-level test.

The service shell's "MMC slave" submenu checks the remote control functions and, with an audio disc playing, the left and right channels and mono and stereo. The slave processor (7206) on the MMC panel sets the APU attenuators 7506 and 7507 through the serial-to-parallel converter 7508, and one step of the counter in the menu is 1 dB.

Low-level test

The low-level test lives in the boot code of the system ROM and needs no working RAM. It checks the video controllers, the ROM checksum, the NVRAM, both DRAM banks, the CDIC RAM and registers, and communication with the slave processor; a last step calibrates the clock. It runs through port 2 on the rear, the SCC68070's own UART, in one of two ways:

• With a VT100 or compatible terminal set to 9600 baud, 8 data bits, 1 stop bit, no parity and no handshake: switch the player off, connect the terminal, and switch on while holding the terminal's space bar. The terminal version shows full error details, for example the address, the data read and the data expected for a memory error.
• With Philips's service PCB, which has an 8-digit display and TEST, Yes and No keys: connect it to port 2 with the player off and switch on. The display shows "CDI RLxx", where xx is the release number.

Low-level test error codes

Code	Meaning	Code	Meaning
Er05	ROM checksum error	Er14	DRAM bank 0 error, inverted data
Er09	NVRAM error	Er15	DRAM bank 1 error
Er10	NVRAM error, inverted data	Er16	DRAM bank 1 error, inverted data
Er11	DRAM error, banks 0 and 1	Er17	CDIC RAM error
Er12	DRAM error, banks 0 and 1, inverted data	Er18	CDIC RAM error, inverted data
Er13	DRAM bank 0 error	Er19	CDIC register error
Er20	Wrong echo from the slave processor	Er21	Invalid release number from the slave processor
Er22	Invalid release number from the CD processor

After an error the test asks whether to restart; answering No moves on to the next test. Philips's rule is to replace the MMC unit if the low-level test reports a fault.

MMC board checks

If the low-level test cannot be started at all, check the supplies and clocks on the MMC panel. If they are all present, Philips's advice is to replace the MMC unit.

MMC panel supply at connector M1

Pin	Supply	Pin	Supply
1	+5 V ±5 % (digital)	5	Analogue ground
2	+5 V ±5 % (digital)	6	+5 V ±5 % (analogue)
3	Digital ground	7	−12 V ±10 %
4	Ground	8	+12 V ±10 %

Measure the clocks just after a reset, which happens at power-on and each time OPEN/CLOSE is pressed:

• System clock 30.0000 MHz ±1500 Hz (PAL) at IC7201 pin 30 and pin 119 of IC7101 and IC7110; half of it, 15.000 MHz, at IC7201 pin 29.
• 68070 UART clock 4.9152 MHz at IC7201 pin 69; DUART clock 3.68684 MHz at IC7241 pin 32; 68HC05 slave clock 4.000 MHz at IC7206 pin 39.
• CDIC clock 22.5792 MHz at IC7301 pin 94; DSP clock 7.5264 MHz at IC7306 pin 16.
• With the player running, the 68070 (IC7201) should have HALTN (pin 27), RESETN (pin 28) and BERRN (pin 26) high and DTACKN (pin 24) switching. RESETN is low for 250 ms ±20 ms at reset, and RESETCD goes low for 140 ms ±20 ms when OPEN/CLOSE is pressed and again when it is released.

Disc faults

The CD part is in effect a CD player. If the mechanism does not start, check the supply, clock and reset on the CD drive processor, then run the X-bus test in the service shell and look for activity on the X-bus and SPI bus. A communication failure points to the system control side, so run the low-level test. If the buses work, use the service shell's CD test modes, which exercise the optical unit, the turntable motor and the swing arm. If the servo works, look for activity on the I²S lines (DAAB, CLAB, WSAB) and subcode lines (SCAB, SDAB) from the SAA7310 decoder; if there is none, check its supply and its HF and XIN inputs, and if there is, check the ADOC (audio digital output) circuit.

CD panel measurements (section 7.2.2), test disc 5

Check	Where	Expected
Laser current	Across 3114 (measuring points 1 and 2), track 1 playing	0.7 V DC ±10 %
Focus	Across 2151 (measuring point 3 to ground), track 1 playing	+400 mV DC ±10 %
Start-up	Across 2112 (measuring point 4 to ground) after pressing play	Start-up waveform on an oscilloscope
Motor control	IC7181 pin 1 to ground, track 1 playing	−1.7 V DC ±10 % once settled
Measuring point 6	To ground, track 1 playing	3.2 V DC ±10 %
Drive processor clock	Measuring point 29	4 MHz
Decoder clock	Measuring point 34	11.2896 MHz

The laser current is set at the factory and is not adjusted after replacing a CDM-9.

Audio faults

If a CD-i disc gives pictures but no sound, the servo and decoding are working and the fault is in the audio path. The APU panel plugs into the CD panel: two connectors underneath carry its supplies and outputs, and three on top come from the MMC panel. Check the I²S input from the MMC on the 7-pin connector A016 on top of the board and the analogue output on the connector underneath. Signals at the input but not at the output put the fault on the APU; audio at the APU output but not at the sockets means following the signal across the CD panel, including its kill (muting) and buffer circuits. Philips's extension connectors 4822 321 22268 (two are needed) lift the APU into a service position. The XIN clock at test point 61 (connector A023 pin 2) should be 11.2896 MHz with a CD-DA track playing and 9.767 MHz with CD-i level A or B audio.

Video faults

Use two extension cables 4822 321 22267 to reach the video encoder panel. Philips's three worked examples:

• The player shell appears but video from the disc does not. The encoder and the video synthesiser are working, so the fault is in the video decoding on the MMC panel.
• No video at all. Check every output (S-video, RF and composite). If none works, check the RGB, composite sync and supply inputs from the CD panel to the encoder at connector 1061 underneath the encoder panel. If they are present, check the encoder IC and its Vcc1 and Vcc2 supplies: if both are missing check resistor 3660, if only Vcc1 is missing check 3618, and if only Vcc2 is missing check 3619.
• No colour. Check the subcarrier oscillator at pin 6 of the encoder IC, then the chroma output at pin 15, the chroma input at pin 17 and the coupling parts between them, and the composite output at pin 20. If chroma is missing at the output, suspect the encoder IC 7601.

The PAL subcarrier at test point 83 (pin 6 of IC7601) should be 4,433,618 Hz ±50 Hz at 400 to 1000 mV peak to peak. If the frequency is wrong, set the standard switch SK-2 to 625 (PAL), connect a counter to test point 75 (pin 8 of IC7667) and adjust trimmer 2681 on the encoder panel to 4,433,618 Hz ±50 Hz. The PAL composite output at test point 89 should be 1000 mV with 710 mV white level, 290 mV sync and 230 mV burst. The control signal SW at test point 78 should be low.

Tray will not open

A Philips service note bound into the manual explains that all CD-i players with a tray have a shop demonstration mode. A customer can switch it on by accident by holding the STOP key while turning the player on. In this mode the tray cannot be opened, so a disc cannot be removed, and the open icon is missing from the on-screen menu. Turn the player off with the on/off key and turn it on again while holding STOP; the open icon returns once the mode is off.

Settings lost, memory full or blue screen

The 205 keeps its settings, clock and saved data in an 8 KB MK48T08B Timekeeper on the MMC board, which has its own internal cell. A flat cell loses the data and the time at power-off and can stop the player at a light blue screen or a "memory full" error. The low-level test checks the NVRAM (Er09 and Er10 above). Replacement and clock calibration are described on the maintenance page.

Supply voltages

Test the power supply out of the player with a load on the +5.2 V output, never without one: Philips specifies 4 Ω 25 W in the measurement section and 5 Ω 10 W in the troubleshooting section.

Power supply checkpoints

Supply	Nominal	Connector and pin
+5.2 V	+5.3 V	P0006 pin 4
+12 V	+12.1 V	P0005 pin 1; M7 pin 8 (MMC panel)
−12 V	−12.1 V	P0005 pin 2; M7 pin 7 (MMC panel)
−8 V	−8 V	P0004 pin 6; C1 pin 3 (CD panel)
+8 V	+8 V	P0004 pin 7; C1 pin 2 (CD panel)
+30 V	+28.5 V	P0004 pin 8; C1 pin 1 (CD panel)

Set +5.2 V with trimmer R3020 to 5.3 V ±40 mV at test point 51.

Related pages

• Philips CDI 205
• Philips CDI 205 General Maintenance
• Philips CDI 205 Capacitor Replacement Guide
• Philips CDI 205 Documentation
• Philips CDI 910 Troubleshooting Guide
• Philips CDI 220 Troubleshooting Guide