Thread: Aiwa AD-F410
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Old 29th Apr 2019, 6:59 pm   #7
Chris55000
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Join Date: Aug 2007
Location: Walsall Wood, Aldridge, Walsall, UK.
Posts: 2,853
Default Re: Aiwa AD-F410

Hi:

S.M.:–

https://elektrotanya.com/aiwa_ad-f41.../download.html

(It's a reasonably clear and readable one!)

Have you checked the capstan motor is receiving it's power–supply voltage? A lot of these logic–controlled mechanisms will clatter away twenty to the dozen "ad nauseum", trying to see the missing reel sensor pulses in vain if one or more of the motors is not running!

Turn to the mechanism control circuit–diagram on p10 of the s.m., locate pin 4 of P903 on the mechanism control pcb, and make sure the "VM" motor power supply is present and correct, and fusible resistor R877 is not open–circuit.

If R877 has failed, this may be due to an internal fault in the capstan motor itself, the mechanism jamming and overloading the motor or a psu regulator fault further back.

The capstan motor itself can be tested "in–situ" with an ordinary PP3 battery across it's input terminals, whence some signs of rotation should be evident.

No rotation when a battery is tried suggests a motor internal failure, whilst normal rotation suggests the power supply from is Q803 is low or missing.

If R877 is intact but Q803 is not providing power, check pin 23 of the control micro (/O–CMTR) is correctly going low (< 0.5V) when the play key is operated – if so, Q803 is suspect and a replacement should be tried.

If pin 23 of the control micro is not going low, there are other things to check first, but look at these few items first and report back, then I'll help you go thro' the control circuits a bit further if need be!

Chris Williams
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