Realistic Lab 500

[Craig Fowler]

Hi all,

My Realistic Lab 500 stopped playing mid-record. It appears the motor simply died. Any suggestions or is it likely done for after 40+ years. I am concerned my use of a record weight may be to blame which makes it all the worse. On a positive note it died while playing Steely Dan's Aja! Hope I go out the same way.

 

[Bob in WI]

Hi all,

My Realistic Lab 500 stopped playing mid-record. It appears the motor simply died. Any suggestions or is it likely done for after 40+ years. I am concerned my use of a record weight may be to blame which makes it all the worse. On a positive note it died while playing Steely Dan's Aja! Hope I go out the same way.

I wouldn't think the record weight had anything to do w it & I would not consider the TT dead yet.

 

[Mitch Wright]

Seems unlikely the motor itself died. If it is like the Lab 400, the table has many electrolytic caps in the power supply, motor controller, etc. My guess would be a cap has failed open or shorted. If the latter, the cap may have taken resistor(s) with it.

Are there indications of power to other parts of the table (e.g. strobe)?

 

[tubewade]

There is no strobe as its quartz locked.

If you move the tone arm to the end of the record do you hear the cycle solenoid engage? If not, the power supply has probably failed. May be a simple fix. If it does engage disconnect power to release the solenoid.

 

[Craig Fowler]

Tested transformer. 1

There is no strobe as its quartz locked.

If you move the tone arm to the end of the record do you hear the cycle solenoid engage? If not, the power supply has probably failed. May be a simple fix. If it does engage disconnect power to release the solenoid.
130 V approx in and 23 V out. No sound of the solenoid. Lifting the tone arm does engage the motor as it should. No visible sign of any obvious issues inside the unit. Wondering if any of the mechanics inside are not engaging properly. Weird that the thing simply stopped working during playback.

 

[tubewade]

From the power transformer 23VAC >> thru the power switch on the white wires >> to the bridge rectifier. With the switch closed, tonearm in playing position, you should have about 32VDC at the 470uF capacitor and the collector of the voltage regulator transistor 2SD360 which is the red wire on terminal 11. The emitter of the 2SD360 should show 24VDC which is the blue wire on terminal 13. That 24VDC powers everything. You've ruled out the power transformer. Now we need to rule out the power switch, the bridge rectifier and the voltage regulator circuit.

 

[Craig Fowler]

So with the help of a good friend we traced the issue to the motor. After removing it it was apparent that it was not moving freely. Removed the lower access to the shaft and after a couple of good taps the magnet and spindle freed up. Replaced it in the unit and tested perfectly. Really wonder if the record weight was applying a downward force onto the motor until it eventually jammed tight. Thankfully, I can put the Rega RP 1 back in storage for when it is next needed. What van I say I love the automatic features. Speaking of which every time I switch the player on, the Repeat/Single Play knob rotates clockwise, putting it in Repeat mode. Any ideas as to why this might be happening?

 

[Montycat]

Glad you got it going. I have a LAB-500 too but it barely gets used as it's at our cabin. I'm not that surprised to hear the motor was kind of seized. The manuals probably say things like "never needs lubrication" but they might not have anticipated 40 years later.

When you put it back together you might have had something slightly out of place related to the repeat switch. You'll probably have to open it again to check.

 

[Craig Fowler]

Glad you got it going. I have a LAB-500 too but it barely gets used as it's at our cabin. I'm not that surprised to hear the motor was kind of seized. The manuals probably say things like "never needs lubrication" but they might not have anticipated 40 years later.

When you put it back together you might have had something slightly out of place related to the repeat switch. You'll probably have to open it again to check.

The issue with the Single Play/Repeat knob existed prior to the motor issue. Starting a record results in the single play/repeat button's rotation for some unknown reason. It actually moves it beyond both the single play and repeat position. Resulting in the automatic repeat occurring.

 

[polypetalous]

Glad you got the 500 going again.
My “play/repeat” knob moves a little when starting a record but stays at “single play” or whatever I select.
Though my “play/repeat” knob also has a third position beyond “repeat.”
With a record on the mat and arm at rest, if I turn the knob beyond repeat, to an unmarked position, the platter will spin without the arm moving.
Weird and not sure if it’s a feature or an oddity in my unit.
Love the Lab-500 though, been very solid and reliable for me.
Good luck!

Ben

 

[tubewade]

The LAB500 here has three positions. Repeat - Single Play - Unmarked position. If the knob is moved to Repeat or the unmarked position the motor starts but the arm remains at rest. If automatic play is activated with the knob at "Single Play", it will move to the third unmarked position while the cycle is commencing, then it automatically returns to the "Single Play" position.

The 500 has also been solid and reliable for me and has been my primary deck for a long time. It sounds much better than the Yamaha in my avatar, which is located in a different room.