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Exactly as described, a Service Manual complete with the schematics and PCB layout delivered in a timely manner. Many thanks for the great service.
some of the writing is a bit blur but the part in the schmatic was great and i have fixed the machine thanks
Well.. I'd searched for this manual and although I found many copies online I was pleased to find your website with a well balanced pricing system and easy to search and follow links. That together with the very quick response time was just what I was looking for.. being a very impatient tech.. ;-) I had the service manual in front of me within a short time.
Bookmarked.. and you can bet I will always come here first for my service & user manuals..
I will definitely be back for more information when I need it.
The service manual when downloaded and printed out was clear and easy to read. I would have liked to have been able to enlarge some details, but this was not possible as the file permissions did not allow this. The service was very good. The time taken from placing my order to downloading the document was only a few minutes.
3-4-2. Normal Audio System Adjustment â¢ Make adjustment in the SP mode, unless otherwise specified. Use a normal VHS cassette for an adjustment tape. â¢ Set AUDIO MONITOR to normal. [Adjustment Sequence] 1. 2. 3. 4. ACE Head Adjustment E-E Output Level Check Frequency Responce Check Overall Level Characteristic and Distortion Factor Check 5. Overall S/N Check 1. ACE Head Adjustment Refer to the service manual of VHS MECHANICAL ADJUSTMENT VI. 2. E-E Output Level Check Purpose: Confirm that the output level against the reference input is within the specification. Mode Signal Measurement point Measurement equipment Specified value E-E L, R: 400 Hz, â7.5 dBs Audio output terminal Audio level meter â7.5 Â± 2 dBs
4. Overall Level Characteristic and Distortion Factor Check Purpose: Check the record level, play level, and distortion factor against the reference input. Mode Signal Measurement point Measurement equipment Specified value REC and PB (SP mode) 400 Hz, â7.5 dBs Audio output terminal Audio level meter and distortion factor meter Playback level: â7.5 Â± 4 dBs Distortion factor: 4% or less
PARTS ARRANGEMENT DIAGRAM FOR ADJUSTMENTS
MA-325 BOARD (Side A)
Confirmation Method: 1) Supply an audio signal of 400 Hz, â7.5 dBs simultaneously to both L and R channels of Audio Line Input. 2) Make recording 3) Play back a recorded portion. 4) Confirm that a playback level is â7.5 Â± 4 dBs. 5) Confirm that a distortion factor is within 4%. 5. Overall S/N Check Purpose: Confirm that the S/N is within the specification. Mode Signal Measurement point Measurement equipment Specified value REC and PB (SP mode) Short Audio output terminal Audio noise meter â46.0 dBs or less
Confirmation Method: 1) Simultaneously input a signal of 400 Hz, â7.5 dBs to both L and R channels of Audio Line Input. 2) Confirm that the audio output level is â7.5 Â± 2 dBs. 3. Frequency Responce Check Purpose: Confirm that the frequency characteristic is within the specification. Mode Signal Measurement point Measurement equipment Specified value REC and PB (SP mode) 400 Hz, â30.0 dBs 7 kHz, â30.0 dBs Audio output terminal Audio level meter 1 Â± 4 dB
Confirmation Method: 1) Connect both L and R channels of audio line input to the GND. 2) Start recording. 3) Play the recorded part to confirm that the noise is below â46.0 dBs.
SR-718 BOARD (Side A)
VIDEO SYSTEM ADJUSTMENT
RV201 6V ADJ
Tape path adjustment must have been completed. Confirmation Method: 1) Supply a signal of 400 Hz, â30.0 dBs to both L and R channels of Audio Line Input. 2) Connect the audio level meter to the Audio Line Output. 3) Adjust the attenuator so that the audio level meter will indicate â30.0 dBs. 4) Make recording in the SP mode. 5) Set an audio line input signal to 7 kHz and make recording. 6) Playback a recorded portion, and measure output levels at 400 Hz and 7 kHz. 7) Confirm that the 7 kHz playback output level within a range of the 400 Hz playback output level 1 Â± 4 dB.
VCO Oscillation Frequency Adjustment (MA-325 Board) Purpose: Adjust to set the character position on the screen. Mode Signal Measurement point Measurement equipment Adjusting Element Specified value E-E Color bar Pin @Â§ of IC401 Oscilloscope (DC mode) CT401 2.75 Â± 0.05 V
VDD = 5.0V 1H
2.75Â±0.05V GND = 0V