Philips CDI 220 Troubleshooting Guide

Rear of a CDI 220/77. Input 2, beside the digital output, is the rear port used for the terminal in the low-level test (photograph: Evan-Amos)

Fault finding on the Philips CDI 220 starts with the version number on the type plate, because the 220 was built on five different mainboards and power supplies; the versions table lists them. Philips built three test programs into the player and its service manuals give supply voltages, clock frequencies and servo readings for each board. For dismantling, NVRAM replacement and fuse positions see Philips CDI 220 General Maintenance; capacitor lists are on Philips CDI 220 Capacitor Replacement Guide.

Symptoms and first checks

Common symptoms

Symptom	Probable cause	Action
No sign of life	Mains fuse, or wrong supply voltage	Check the input voltage and the main fuse on the supply board, then the rail fuses: 1805 and 1806 on Mono I and II, 1201 to 1204 on Mono III and IV
Display only dimly lit, player behaves strangely	European or UK Mono I/II player run on 120 V	Use a step-up transformer
Display and front buttons dead, controller port dead, a motor runs all the time	Front panel cables swapped, and/or fuse 1806 (−5 V) blown (Mono I/II)	Check the cable positions and 1806
Rolling or flickering picture, tray opens by itself, spindle runs all the time, "cd" flashing on the display	−5 V fuse on the mainboard blown (3274 on Mono III, 3255 on Mono IV)	Measure −5 V; replace the fuse
Settings and clock lost, "memory full", light blue screen	Flat battery in the NVRAM	See below
Disc does not spin or is not read	CD mechanism, or the servo circuit	Run the CD drive test in the service shell
Player shell does not start	Fault in the MMC section or its supplies	Run the low-level test

Built-in test software

The 220/20 manual describes three test programs: a front display and keyboard test, the low-level test, and the service shell.

Display and keyboard test

Hold PAUSE while switching on. After about five seconds a "0" appears on the display. Press the front keys in the order EJECT, PREVIOUS TRACK, PLAY, NEXT TRACK, PAUSE, STOP; the counter goes up by one for each correct key. Any further key starts the display test, in which every key except PLAY switches all display segments on and off and toggles the internal NVDS signal, so the picture on the TV disappears and returns. PLAY starts the player shell.

Service shell

Connect RXD and TXD of the front input port (port 1, pins 2 and 3) before switching on or resetting; the player then starts the service shell instead of the player shell. retrostuff uses a dummy plug with pins 2 and 3 shorted for the same purpose. The menus test the video circuits (a colour bar pattern), the CD mechanism and servo, the input and output ports, and the audio circuits. The CD and audio tests need an audio CD.

The CD drive test in the 220/20 manual steps through four modes:

• Mode 0: the CD processor software release is shown; ARM IN and ARM OUT move the lens inwards and outwards.
• Mode 1: the drive tries to focus. IN FOCUS is a pass; NO FOCUS appears after 16 attempts and the test returns to mode 0.
• Mode 2: the turntable motor runs, controlled by the rough HF signal; moving the lens outwards by hand should slow the disc.
• Mode 3: ARM IN and ARM OUT make the lens jump in small steps. NEXT STEP then starts normal play, with errors from the CD processor shown on screen.

retrostuff warns, from a CDI 470 with a CDM 12.1, to press SLEDGE OUT and SLEDGE IN only once or alternately, because the sledge will otherwise try to go past its limits and can damage the gear racks.

The APU/key menu tests the audio attenuators and shows the name of each remote or front key while it is held; attenuation 47 is the maximum (no sound).

Low-level test

The low-level test is part of the boot code and runs without external RAM, so it works when the player shell does not. Connect a VT100 terminal (or a PC terminal program) to the 68070's UART on port 2 at the rear, set to 9600 baud, 8 data bits, 1 stop bit, no parity and no handshake, and switch the player on while pressing the space bar. Philips's own service PCB plugs into the same port. The test covers the ROM checksum, NVRAM, DRAM, the CDIC, the slave processor and the X-bus between the DSP and the servo processor.

Low-level test error codes (220/20 manual, table 2)

Code	Meaning
Er05	ROM checksum error
Er09	NVRAM error
Er10	NVRAM error (inverted data)
Er11	DRAM error, bank 0 and bank 1
Er12	DRAM error, bank 0 and bank 1, inverted data
Er13	DRAM bank 0 error
Er14	DRAM bank 0 error, inverted data
Er15	DRAM bank 1 error
Er16	DRAM bank 1 error, inverted data
Er17	CDIC RAM error
Er18	CDIC RAM error, inverted data
Er19	CDIC register error
Er20	Slave error (wrong echo from the slave processor)
Er21	X-bus transfer error

Philips's rule for its own dealers was to replace the monoboard if the low-level test reported a fault in the MMC part, and, if the test would not start, to check the supplies and main clocks first.

Settings lost, memory full or blue screen

The NVRAM is an 8 KB Timekeeper chip or a 32 KB SmartWatch socket with an SRAM, depending on version; both contain batteries. A flat battery loses saved data and the date and time, and can stop the player at a light blue screen or a "memory full" error with garbage at the bottom of the screen, or with no picture at all. Back up the NVRAM first and replace the part as described in the maintenance guide.

If the error remains after a new chip, check the socket joints. On a CDI 470, another Mono IV player, retrostuff found that pin 11 of the NVRAM socket (D8NVR) had no proper connection to the board; re-soldering helped only for a while and a wire link to the next test point fixed it.

Disc faults

Philips's approach for the servo and audio sections is the same as for any CD player.

1. If the CD mechanism does not start, check supply, clock and reset at the CD drive microprocessor, then run the X-bus test in the service shell or the low-level test and look for activity on the X-bus and SPI bus.
2. If communication works, use the CD drive test modes to check the laser unit, the turntable and the swing arm.
3. If the servo works, look for activity on the I²S (DAAB, CLAB, WSAB) and subcode (SCAB, SDAB) lines from the SAA7310 decoder; if there is none, check its supply and its HF and XIN inputs.

On the CDM 12.1 of a CDI 470, retrostuff cured a MOTOR ERROR in mode 2 by lifting the turntable with a flat tool, following a tutorial from The World of CD-i, then greased the sledge gears and guide rod. Philips replaced the CDM 9 as an assembly and its laser current is set at the factory.

Servo measurements (220/20, CDM 9)

Philips's readings on the CD panel, with track 1 of test disc 5 playing unless stated:

Servo test points (220/20 manual, section 7.2.2)

Signal	Where	Expected
Laser current	Across 3411 (measuring points 1 and 2)	0.7 V DC ± 10 %
Focus	Across 2431 (measuring point 3 to ground)	+400 mV DC ± 10 %
Motor control	IC7445A pin 3 to ground, after a while on track 1	−1.7 V DC ± 10 %
Motor control	Measuring point 6 to ground	3.2 V DC ± 10 %
Radial error	Measuring point 18	2.6 V DC ± 10 %
Radial error	Measuring point 19, in play	110 mV DC ± 10 %
Radial error	Measuring point 21, in play	1.2 V DC ± 10 %
Logic levels	Measuring points 23, 24, 26, 27	0 V low, 5 V high, depending on mode

Video faults

The 220/20 manual separates the cases:

• Player shell visible but no video from discs: the fault is in the video decoding on the MMC section.
• No video at all: check every output (S-video, RF and composite). If none works, check the RGB, composite sync and supply inputs to the video encoder; if they are present the digital video circuits are working and the fault is in the analogue video circuit.
• No colour: most likely the encoder circuit. Check the subcarrier oscillator at pin 6 of the video encoder IC7609, the chroma output at pin 15, the chroma input at pin 17 and the composite output at pin 20.

On the Mono III board the encoder is the Bt9106 "Calvin" (IC7160); for no colour Philips says to check the CVBS output on pin 2 of IC7160.

Supply voltages

Mono I (220/20)

Mainboard connector 1001 (220/20 manual, section 7.2.5.1)

Pin	Expected
1, 2, 3	+5 V ± 5 %
4	−5 V ± 5 %
5	+25 V ± 5 %
6, 7, 8	Ground

The +5 V rail is set with trimmer 3807 on the power supply panel. Just after a reset (pressing OPEN/CLOSE or switching on) the system clock should be 30.0000 MHz ± 1500 Hz (PAL) or 30.2098 MHz ± 600 Hz (NTSC) at IC7201 pin 30, half that at IC7201 pin 29, 4.9152 MHz at pin 69 (the 68070 UART clock), 4.000 MHz at IC7206 pin 39 (the 68HC05), 22.5792 MHz at IC7301 pin 94 (the CDIC) and 7.5264 MHz at IC7306 pin 16 (the DSP).

Mono III (220/60)

Supply pins of the main ICs (220/60 manual, section 7.3.1)

Position	IC	Pins	Expected
7210	68070	1, 43	+5 V ± 10 %
7201	IKAT (MC68HC05i8)	59	+5 V ± 10 %
7240	System ROM (27C400)	22	+5 V ± 10 %
7241	NVRAM	28	+5 V ± 10 %
7125	VDSC	3, 9, 27, 36, 41, 61, 80, 95, 100, 112, 119, 124, 130, 140, 148	+5 V ± 10 %
7160	Calvin	16, 22, 51, 57, 61, 65, 66	+5 V ± 10 %
7310	CIAP	6, 20, 27, 35, 45, 58, 66, 76	+5 V ± 10 %
7401	DSIC2	12, 20, 28	+5 V ± 5 %
7510	CD60	11, 15, 17, 29, 31, 42, 44	+5 V ± 5 %

retrostuff points out that the manuals say little about where to measure −5 V; it feeds the servo op-amps and the audio and video amplifiers. On the large Mono III and IV players the +24 V (or +12 V) rail usually appears on the connector to the display panel.

Related pages

• Philips CDI 220
• Philips CDI 220 General Maintenance
• Philips CDI 220 Capacitor Replacement Guide
• Philips CDI 220 Service Manuals
• Capacitor Failure Symptoms