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Teac A4010S parts list?

nsgn007

nsgn007

Active Member
working on this unit, it is a later model as the SN starts with 96 ... the service manual from HiFi engine has no parts list and it needs the rec bulbs , and I am getting conflicting responses some claim they use filament bulbs and some say they used neon bulbs ... the bulbs themselves are MIA so I don't know which to use and pushing the rec buttons does not engage the relay , so that might be an issue as well because I cant check the supply voltage for them ... anyone have a parts list for this?
Thanks
 
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nsgn007 said:
the bulbs themselves are MIA so I don't know which to use and pushing the rec buttons does not engage the relay , so that might be an issue as well because I cant check the supply voltage for them
Click to expand...
Did you also press the forward play button while pressing down the left and right record buttons to initiate recording?
 
Yes... the relay is not doing anything , also the VU lights are out and they seem to be internally wired inside the VU meter , not sure which terminal on the back would be power for the lights , as I get nothing but a few mv on my VOM while the machine is on while checking the terminals on the backs of the meters ....
 
This section of the RA-40S schematic shows the left and right rec lamps (PL5 and PL6) are neon lamps that are driven by voltage obtained from the output winding of the bias oscillator transformer. They are switched on when record relays K5 and K6 are activated. You need to determine why these relays are not activating when the record push button(s) and forward play buttons are pressed.

Teac RA-40S Rec Lamps.jpg
 
Greetings from RojoLand!

"it is a later model as the SN starts with 96 ..." — Which means we need to know if your record amplifier is the older RA-40S or the newer AR-40S. They are different. The RA-40S does use NE-2 neon lamps, powered directly from the bias oscillator via 10k series resistors; the even older RA-40 with no 'S' suffix uses incandescent lamps, I believe 24 V. The AR-40S reverts to incandescent bulbs (6 V). Big issue with the A-4000/A-4010 models is that there are several schematics over its manufacturing life (over 240,000 units were built — the last serial number is 243460).

Be advised also that the RA-40/-40S use PNP, mostly germanium transistors so the power supply is positive-ground; the AR-40S is almost all-NPN silicon and has the usual negative-ground supply.

Take care,
—
J. E. Knox "The Victor Freak"
Current caretaker of A-4010S S/N 48104
 
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