Philips BJ2.4U Service Manual

Service Modes, Error Codes, and Fault FindingEN 38 BJ2.4U/BJ2.5U PA5.• Then, after this voltage becomes present and is detectedOK (about 100 ms), the other two voltages (+2V5 and+3V3) will be activated (via ENABLE-3V3).• The current consumption of controller IC 7U00 is around 20mA (that means around 200 mV drop voltage acrossresistor 3U22).• The current capability of DC/DC converters is quite high(short-circuit current is 7 to 10 A), therefore if there is alinear integrated stabilizer that, for example delivers 1.8Vfrom +3V3 with its output overloaded, the +3V3 staysusually at its normal value even though the consumptionfrom +3V3 increases significantly.• The +2V5 supply voltage is obtained via a linear stabilizermade with discrete components that can deliver a lot ofcurrent. Therefore, in case +2V5 (or +2V5D) is short-circuited to GND, the +3V3 will not have the normal valuebut much less. The +2V5D voltage is available in standbymode via a low power linear stabilizer that can deliver up to30 mA. In normal operation mode, the value of this supplyvoltage will be close to +2V5 (20 - 30 mV difference).• The supply voltages +5V and +8V6 are available onconnector 1M46; they are not protected by fuses. +12VSWis protected for over-currents by fuse 1U04.Fault Finding• Symptom: +1V2, +2V5, and +3V3 not present (even for ashort while ~10ms).1. Check 12V availability (fuse 1U01, resistor 3U22,power MOS-FETs) and enable signal ENABLE-1V2(active low).2. Check the voltage on pin 9 (1.5 V).3. Check for +1V2 output voltage short-circuit to GND thatcan generate pulsed over-currents 7-10 A through coil5U03.4. Check the over-current detection circuit (2U12 or 3U97interrupted).• Symptom: +1V2 present for about 100 ms. Supplies +2V5and +3V3 not rising.1. Check the ENABLE-3V3 signal (active "low").2. Check the voltage on pin 8 (1.5 V).3. Check the under-voltage detection circuit (the voltageon collector of transistor 7U10-1 should be less than0.8 V).4. Check for output voltages short-circuits to GND (+3V3,+2V5 and +2V5D) that generate pulsed over-currentsof 7-10 A through coil 5U00.5. Check the over-current detection circuit (2U18 or 3U83interrupted).• Symptom: +1V2 OK, but +2V5 and +3V3 present for about100 ms. Cause: The SUPPLY-FAULT line stays "low"even though the +3V3 and +1V2 is available. The Stand-byProcessor is detecting that and switches all supplyvoltages "off".1. Check the value of +2V5 and the drop voltage acrossresistor 3U22 (they could be too high)2. Check if the +1V2 or +3V3 are higher than their normalvalues. This can be due to defective DC feedback ofthe respective DC/DC converter (3U18 or 3UA7).• Symptom: +1V2, +2V5, and +3V3 look okay, except theripple voltage is increased (audible noise can come fromthe filtering coils 5U00 or 5U03).Cause: Instability of the frequency and/or duty cycle of oneor both DC/DC converters.– Check resistor 3U06, the decoupling capacitors, theAC feedback circuits (2U20 + 2U21 + 3U14 + 3U15 for+1V2 or 2U19 + 2U85 + 3U12 + 3U13 for +3V3), thecompensation capacitors 2U09, 2U10, 2U23 and2U73, and IC 7U00.Note 1: If fuse 1U01 is broken, this usually means a pair ofdefective power MOSFETs (7U01 or 7U03). Item 7U00 shouldbe replaced as well in this case.Note 2: The 12V switch and 8V6 switch (see "DC/DCCONNECTIONS" schematic) are not present on board: theyare bypassed by jumpers.5.9 Software Upgrading5.9.1 IntroductionThe set software and security keys are stored in a NAND-Flash(item 7P80), which is connected to the VIPER via the PCI bus.It is possible for the user to upgrade the main software via theUSB port. This allows replacement of a software image in astandalone set, without the need of an E-JTAG debugger. Adescription on how to upgrade the main software can be foundin chapter 3 "Directions For Use".Important: When the NAND-Flash must be replaced, a newSSB must be ordered, due to the presence of the securitykeys!!! See table “SSB service kits” for the order codes.Perform the following actions after SSB replacement:1. Set the correct option codes (see sticker inside the TV).2. Update the TV software (see chapter 3 for instructions).3. Perform the alignments as described in chapter 8.4. Check in CSM menu 5 if the HDMI and POD keys are valid.Table 5-3 SSB service kitsModelNumberSSB Assy 12 NCnumberNew SSB ordercode37PF9431D/37 3104 328 48001 3104 328 4804142PF9431D/37 3104 328 47981 3104 328 4802142PF9631D/37 3104 328 46531 3104 328 4762142PF9731D/37 3104 328 46541 3104 328 4763142PF9831D/37 3104 328 46541 3104 328 4763150PF9431D/37 3104 328 47981 3104 328 4802150PF9631D/37 3104 328 46531 3104 328 4762150PF9731D/37 3104 328 46551 3104 328 47641