The AKAI 1720 model reel to reel tape recorder described in this Manual is quite an old unit - circa late 1960's. As a consequence, the description of the mechanical details - and adjustments thereof - is quite critical. The manual does this quite well. The schematics are also well presented and have detailed PCB overlays. Probably the only negative is that some half-tone detail has been lost from the original manual as it has been scanned in simple B&W.
Text excerpt from page 19 (click to view)
TROUBLE SHOOTING TABLE (Continued)
LED LIGHT NO NORMAL SOUND
comes No sound from the
Check F4701. F3700. out at AV-out J905 speaker
Normal Blown out
Set volume to maximum. Is there any sound output signal at pin 10 & 14 of IC 301 ?
Check sound output signal from No Yes pin 92 & 93 of IC 2100 and its if there Check related circuit. is sound input connection to
Replace the Fuse.
No signal at pin 2 the speaker Yes
Is the Fuse again blown out? & 21 of IC 301.
Check output main unit ? consisting of IC701, IC702,
Does STBY+5V appear at pin 1 P1001 Check the power circuit T701 and its related parts. signal at pin
68, 69 of IC 2100 and its
the power Check 3V output related circuit. circuit at the front from pin 22 of IC unit consisting of 2100 and its IC4702, IC4701, related parts. D4707 and its related parts.