HITACHI C32WF727N
Manual de Servicio

SM00025 Service Manual

Next enter the digital audio setup menu and change the decode mode from �Auto� to �Analogue�, to �Digital� and then back to Auto. Make sure no �pop� or �crack� noises are heard on the speakers. Access the speaker setup menu via the remote control and turn off all the amplifiers. Check pins 1,2, and 3 of PS08 of the decoder board go low. Any speakers connected should now be muted. DOLBY DIGITAL TESTS **Set the master volume control to maximum. Check that an undistorted continuous* sine wave can be seen at the following level on the channels below at the phono socket E401. *The Audio will obviously show a transient as the track repeats. There should not be a glitch otherwise. Signal L R C LS RS Level 2Vrms / 5.6Vpp @30Hz 2Vrms / 5.6Vpp @30Hz 2Vrms / 5.6Vpp @30Hz 2Vrms / 5.6Vpp @30Hz 2Vrms / 5.6Vpp @30Hz

Signal L R C LS RS

Level 30Hz signal between 2Vrms and 2.1Vrms 30Hz signal between 2Vrms and 2.1Vrms 30Hz signal between 2Vrms and 2.1Vrms 30Hz signal between 2Vrms and 2.1Vrms 30Hz signal between 2Vrms and 2.1Vrms

***The Audio will obviously show a glitch as the track repeats. It should not glitch otherwise. At this point, it is normal that the woofer channel will show clipping. Turn the main volume down and check that you can achieve at least 3Vrms / 8.5Vpp without clipping. Remove the input to E408 and apply the optical input from the DVD player to I407 and repeat the test from ****). MPEG Using an MPEG Multi-channel encoded disc, (such as the film �Jumanji�) apply the digital coaxial or optical output from the player to the amplifier board. Check the OSD displays MPEG Multi-ch. Check audio can be seen at all channels on E401. ANALOGUE / PRO LOGIC MODE Remove the digital source either from I407 or E408. Make sure the volume control is at Maximum. Using a Pro logic encoder, apply a 2V 1KHz Lt Rt signal to the Audio inputs of the selected AV. Using a pro logic encoder, generate signals for each channel in turn (L, R, C and Surround) and make sure they appear undistorted at the correct outputs on E401. At the following levels:Signal L R C Level
1KHz signal between 2Vrms and 2.1Vrms

At this point, it is normal that the woofer channel will show clipping. Turn the main volume down and check that you can achieve at least 3Vrms / 8.5 Vpp without clipping. Remove the input to E408 and apply the optical input from the DVD player to I407. Check the symbol Dolby D 3/2.1 appears (Press recall/info if it doesn�t) Repeat the test from **). DTS Select track 15 on the DTS test DVD. Set the player for �repeat play�. Apply the coaxial output of the player to E408 on the audio amplifier board. ****Set the master volume control to maximum.

LS Check the OSD indicates DTS 3/2.1. If it doesn�t appear, press the recall/info button on the handset. Check for an undistorted continuous*** sine wave can be seen at the following level on all channels at the phono socket E401. 31 RS

1KHz signal between 2Vrms and 2.1Vrms 1KHz signal between 2Vrms and 2.1Vrms 1KHz signal between 1.41Vrms and 1.5Vrms 1KHz signal between 1.4Vrms and 1.5Vrms

Put the master volume to mid way and un-mute the amplifiers via the speaker setup menu.