Technics SL-1210

Technics 1210 Service, Repair & Modification.

 


1210

The Technics SL-1200 started life in 1972 with the SL-1210 being born 6 years later in 1978  The SL-1200 having the silver top and the SL-1210 having the black top. Some 44 years later ! They are still the worlds most popular DJ turntable. If looked after they require very little maintenance and seldom need repair, due to their brilliant design. However DJ’s aren’t the best at looking after their kit, and i find resident Night Club 1200/1210’s tend to be the most neglected.
Things i service and repair the most are Pioneer CDJ’s and Technics SL-1210‘s that are used in Night Clubs or at Festivals. They get drink spilt over them regularly, get left uncovered when not in use and so get lagged with dust. When taking a Deck apart to clean, service or repair, over the years, contaminants i have found inside are:

  1. Dust and lots of it (100’s of people dancing night after night shed their skin, it gets everywhere)
  2. Hair, long or short various colours (how it gets in there i’ll never know, but it does)
  3. Goo ! Yup, when those spilt drinks are ignored they turn into Goo..
  4. White powder (i wonder what that could be)
  5. Rolling tobacco plus remnants of Rizla packets or those little white filters
  6. Various other items from Glitter to Cufflinks !

So i thought it was about time i did a Blog on it. Images can be clicked on to view them full size !


Disclaimer !

All information contained on these pages are here for my reference only, i will not be held responsible for any damage or injury done to you or your equipment ! Some parts of electronic equipment can hold high voltages which can shock or burn, some electronic components are very susceptible to static discharge. Aging IC’s and pcb tracks can be easily damaged if due care is not used when working on them…
You have been warned !


Pitch fader ‘Click Removal’ Modification.

 

1210_jig
To make working on a Technics turntable easier i have a purpose built jig, which means i can access both sides of the deck at the same time.


! Before working on ANY electronic equipment i ALWAYS disconnect it from the mains electricity !

1210_headshell

I started by removing the Ortofon headshell first.



1210_pitch_knob
Then using a plastic pry tool (came in a iphone tool kit) i gently pry’d off the pitch knob…



1210_knob_washer

… and removed the square cloth washer and pitch knob.



1210_spindle
If a platter hasn’t been removed in a long time, it can be quite difficult to remove. I like to give the spindle a couple of light taps with the butt end of a screwdriver, this normally free’s the platter up.
I could then put one finger from each hand into each hole and gently prise the platter off the spindle…



1210_platter_remove
…and lift the platter clear.



1210_pcb_cover
Now i can access to the pcb cover and undo the 5 x screws (arrowed).



1210_platter_pry
Using the pry tool again, i could then lift up the pcb cover… (note how dusty the cover is)



1210_pcb_cover_remove
…and remove it clear of the deck.



1210_pcb_cover_gone
This is the main pcb, motor and power supply.



1210_pitch_connector
I then disconnected the pitch connector here, depending on the age of the turntable this connector could be black in colour…



1210_jig_in
…turned the deck over and mounted it in the jig.



1210_feet
Next i removed the 4 x adjustable legs by turning them anti clockwise until they are free of the base.


1210_screw_type
There are 3 kinds of screw in the base, to make it easy i’m going to call them A, B and C type screws, there are:

  1. 4 x A type screws (these are hidden by the adjustable feet, hence removing them first)
  2. 6 x B type screws
  3. 11 x C type screws


1210_a_screws
A type screws are located here (arrowed).


1210_B_screws
B type screws are located here (arrowed).



1210_c_screws
C type screws are located here (arrowed).



1210_scew_bag
Once removed i put all external screws plus the pitch fader knob and washer in a clip top bag, and labeled it so i know at a glance which piece of equipment they are from !



1210_peel1
I then gripped the back corner of the base firmly and pulled it towards me, as it starts to free from the top…



1210_peel2
I then slide my hand along the side, so it starts to free at both corners.


1210_base
Working along the front edge, eventually the base will come free and it can be moved clear of the deck. The power lead, ground lead and phono leads are all threaded through holes in the base, so i slide the base over these and put it to one side.



1210_hinge_brackets
There are normally two lid hinge brackets, shown here on another turntable.



1210_hinge_plate
But these were already missing on this deck, though a hinge screw plate was still in this one, so i removed it and put it in the casing screw clip top bag.



1210_inside_base
This is what you can see with the base removed. The pitch fader assembly, the pillar lamp assembly, the bottom tone arm pivot cover and the speed button / on off switch assembly.



1210_pitch_fader_pcb
As i’m going to perform the “click removal” mod i need to start here at the pitch fader assembly.



1210_fader_undo
I remove the bottom screw…



1210_pitch_ground
…and then the top one that is also holding the pitch assembly ground wire in place (arrowed)



1210_pitch_led
I then unsoldered the pitch zero LED using my Metcal soldering station.


1210_pitch_braid
Using solder braid (or wick) to clear the holes of any remaining solder.


1210_solder_sucker1
Using a solder sucker along with my soldering iron, i then removed the solder from the pitch fader pins top…



1210_solder_sucker2
…and bottom.


1210_pitch_flux
To be able to remove the pitch fader from the assembly, every little bit of solder needs to be removed from the pins, the old solder can be quite stubborn to shift, so i added a little liquid flux…



1210_pitch_braid_remove
…and then finished up using solder braid (or wick).



1210_pitch_strap
Hidden inside the main body of the deck is an adhesive fabric strap holding down the pitch loom. this needs to be lifted at one end. I did this using a small flat bladed screwdriver.



1210_pitch_remove
I could then lift the pitch fader assembly free of the deck.



1210_pitch_led_out
…and remove the pitch zero LED i had unsoldered earlier. I made a note of which way round it came out of the assembly, so i can refit it the same way.



1210_pitch_solder_gone
Here is the pitch fader assembly, free from the deck with the LED removed and all the pitch fader pins free of solder. 2 of the pins top and bottom (4 in total) are twisted at the factory, to hold the pitch fader in pace before soldering. These need to be twisted straight, to be able to remove the pitch fader from the pcb.


1210_pitch_pin_twist
Using snub nosed pliers, i twisted each pin straight.



1210_pitch_free
I then turned the pitch fader assembly over, undid the 2 fader plate screws and removed the plate. I then grabbed the fader in the middle with one hand and the pcb with the other hand and very gently wiggled them until…



1210_pitch_apart
…the fader came free of the pcb. This is a very delicate proceedure, if ANY solder is left on the fader pins, it will not come apart and there is a risk of damaging the pcb solder pads.


1210_tabs
To gain access to the inside of the pitch fader i need to undo 10 x locking tabs (arrowed).


1210_pitch_pin_bend
I start by putting the pitch fader back in its location but minus the pcb, this way i can work on it without the pitch lever getting in the way, as its resting in its slot. I then took a small flat bladed screwdriver and gently started to bend up each tab, these are quite stiff. I want to get them to a point where i can grab each tab with some pliers.



1210_tab_bend
I then took some snub nosed pliers and straightened each tab up until they were all standing vertical.



1210_tab_apart
I could now gently prise the slider contact pcb from the rest of the fader.



1210_slider_contact
With the slider pcb out the way, i am now left with the pitch fader housing and the pitch lever/contact block (white plastic bit) The arrow shows the location of a hidden coil spring and very small ball bearing, this is located in the side of the white plastic block, its what gives the pitch fader its ‘click’ when reaching zero. With the fader in the position i’m holding it now, if i were to push the pitch lever upwards, it would come free of the housing BUT the tiny spring would fire that ball bearing across my workshop like a little bullet and it would get lost…



1210_freezer_bag
…as i want to keep the spring and ball bearing in case the turntable needs to be put back to standard in the future, i go and get a frezzer bag from the kitchen.


1210_fader_in_bag
I then put the fader and my hands inside the bag and push the lever/contact block out of the housing inside the bag. This way the ball bearing and coil spring will only end up inside the bag !



1210_spring_slot
This picture taken after i have removed the coil spring and ball bearing, shows the slot that they are located in (arrowed).



1210_spring_ball
Heres the coil spring and ball bearing, these i added to the internal parts bag, making sure to clip it shut.



1210_slider_board
Now its time to clean the slider pcb, as its very dirty..



deoxit
Personally i like to use Deoxit Faderlube, as it cleans and lubricates at the same time. Where alot of people go wrong is they buy a tin of fader cleaner or switch or contact cleaner and then just spray it in any hole / slot they can find in the fader, some people do this with the fader still in the deck. But all its going to do is create an abrasive paste when the lube mixes with the dirt and dust thats already in there, sure it’ll work for a bit, but then eventually it will get worse than before…



1210_slider_clean
…better to do the job properly and remove all the dust and grime. I spray one end of a Q-tip with the Deoxit and clean all the pcb tracks, once the pcb tracks are clean i then flip the Q-tip over re-apply Deoxit to the clean bud and then apply a thin film to the pcb tracks…


1210_slider_blow
…which i then blow dry using an airline.


1210_fader_pins_dirty
You can see here that over time grime has built up where the prong is angled, which is the contact point where it touches the pcb.


1210_prong_clean
So i place the fader housing back in its slot, making it easier to work on it, and clean the prongs using Deoxit on a Q-tip, i then finish off by applying a hint of white grease to the edges of the white contact block, before reassembling.



1210_tabs_bend_in
Once reassembled (minus the coil spring and ball bearing) , i then bend the 10 x tabs back over, making sure the fader is firmly back together.


1210_pitch_resolderJPG
Then i resolder the fader to the pcb…



1210_led_resolder
…and resolder the pitch zero LED. Cleaning off any flux residue with isopropanol alcohol. I then thread the fader loom back through the main body of the turntable and screw the pitch fader back in place remembering to refit the ground wire first. Reconnect the pitch fader connector to the mother board and re-attach the adhesive fabric strap over the fader loom, then re-assemble the turntable.


Heres the finished article…


Phono lead testing.

To see how to remove the base of the turntable Click Here.

! Before working on ANY electronic equipment i ALWAYS disconnect it from the mains electricity !

1210_tone_arm_plate
To be able to test the phono leads/connectors, the pivot assembly base plate needs to be removed, so i undo the 2 x screws (arrowed).



1210_cable_clamp
Then the cable clamp needs to be removed, again undoing 2 x screws.


1210_clamp_prise
Using a small flat bladed  scewdriver, i then pry out the locking tabs on the cable clamp, until…



1210_clamp_apart
…the top part is free, i can then lift out the bottom part of the clamp.



1210_clamp_parts
Both parts of the cable clamp.



1210_plate_out
The pivot base plate can now be lifted clear.



1210_beauty
This is the underneath of the pivot assembly, where the phono leads and tone arm wires attach.


1210_phono_test
To test the phono leads and the tone arm wiring i’m going to use a Digital multimeter, set to continuity / diode test mode, it will show .OL (open line) and not make a sound if there is a fault in the wiring…


1210_phono_meter
…but if there is no fault and the wiring is ok, it will read .000 and an audible bleep will be heard all the time the probes are touching the relative connections.


1210_phono_probe
So fault finding is just a methodical approach of testing each wire for continuity. By connecting one probe (RED) of my multimeter to one end of a wire and then the other probe (BLACK) to the other end of the wire, i create a circuit, the multimeter then shows me if the circuit is complete by beeping and showing .000 on the screen. Or if the wire has a break in it, the meter will just show .OL (open line) and no beep will be heard.
I start here by placing my RED probe on the WHITE phono leads hot wire pad (which is WHITE)


1210_phono_probe2
I then put my BLACK probe on the centre (hot) pin of the WHITE phono connector, my meter reads .000 and i have a beep sound the whole time i have my probes connected, so this wire is good, now i’m going to do the same test to the outer wire or braid of the WHITE phono…


1210_phono_probe4
…by connecting my RED probe to the outer (cold) wire or braid pad of the tone arm pcb…


1210_phono_probe3
…and connecting my BLACK probe to the outer (cold) collar of the WHITE phono connector, i perform the same test. Again my meter reads .000 and i can hear a beep the whole time my probes are connected, so this wire is good too. So now i have proved that the WHITE phono is good i can repeat this technique on the RED phono too.


Tone arm wiring testing.

To see how to remove the base of the turntable Click Here.

! Before working on ANY electronic equipment i ALWAYS disconnect it from the mains electricity !


1210_tone_clean
Before testing i clean the tone arm pins with a Q-tip covered in Isopropanol alcohol, as these can get dirty over time, causing bad contact.


1210_tone_colours

Using the same technique described above in phono lead testing, i can test the tone arm wiring too. The colour order on the tone arm pcb is:

  1. BLUE
  2. WHITE
  3. RED
  4. GREEN
  5. BLACK

1210_tone_arm_pins
With the turntable upside down in the jig the tone arm wiring colours at the pins is shown in the picture above, with the inner edge of the outer collar being the BLACK wire from the tone arm pcb.


1210_red_testJPG
Here i am testing the RED wire in the tone arm, by connecting my RED probe to the RED wires solder pad and then…


1210_pin_test2
…connecting my Black probe to the RED pin (note all pins are brass, refer to picture above for colour key) in the end of the tone arm, again testing for coninuity with an audible beep and the multimeter reading .000


Pitch fader range adjustment.

! Before working on ANY electronic equipment i ALWAYS disconnect it from the mains electricity !

1210_platter_lit
This is the strobe light on a Technics SL-1210 (same on a SL-1200) The rows of dots on the edge of the platter when moving correspond to the speed the pitch is set at. Next to the on/off switch is a little decal showing what the dots relate to on the pitch fader. If a pitch fader is replaced, modified or cleaned sometimes the accuracy of the strobe/dot setting can be out in relation to the position of the pitch fader itself. So this needs to be adjusted, which isnt necessarily difficult to do, but some SAFETY precautions NEED to be in place during adjustment !


1210_spindle
To be able to adjust the pitch fader range, i remove the platter first. If a platter hasn’t been removed in a long time, it can be quite difficult to remove. I like to give the spindle a couple of light taps with the butt end of a screwdriver, this normally free’s the platter up. I could then put one finger from each hand into each hole and gently prise the platter off the spindle…


1210_pcb_cover
With the platter removed i then undo the 5 x screws (arrowed) holding down the pcb cover.


1210_pcb_cover_remove
…and remove the pcb cover out the way.


1210_danger
I now have access to the mother board pcb. The area shown inside the RED ring of the turntable is Dangerous *IF* still plugged in to the mains ! Its where the mains voltage supply (230v AC) comes into the turntable, hence it being under a plastic cover (note it is not unusual for this cover to be missing, due care and attention should be used at all times) Hence me making sure at the begining that the turntable is unplugged from the mains !


1210_vr301
Adjustment is made here at potentiometer VR301 it has the word PITCH written above it. Making adjustments is a trial and error thing, so there will be lots of fitting / removing of the platter, making fitting of the pcb cover during adjustments long winded and unpracticle.


1210_platter_no_cover
However, adjustment can be made with the platter in place, via the platter hole nearest the tone arm base. You can see in this pic that the platter is fitted but the pcb cover is not, by the circuitry showing through the platter hole nearest the on/off switch (arrowed).


1210_pitch_set_zero
I turn the turntable on (even though the pcb cover is missing, as there is a gap between the motherboard and platter) and start by setting the pitch fader to the zero position.


1210_pitch_mark

With the platter spinning I then select 33rpm and using a screwdriver as a marker by resting it against the on off switch, check the large dot (zero marker) is sat perfectly still in line with my screwdriver and not moving either to the left or right. If this is good i then…


1210_pitch_6+
…move the pitch fader to the +6 position and…


1210_pitch_mark
…then check that the +6 dot is sat perfectly still and not moving to the left or right. If the dot is moving then it is out of calibration and needs to be adjusted.


1210_off
Safety First ! So i turn off the turntable and unplug it from the mains, by doing this BEFORE EVERY adjustment, i don’t risk electric shock or shorting something on the pcb.


1210_pitch_adjust
I now spin the platter by hand until one of the holes is lined up with the tone arm base, i can then insert my crosshead screwdriver and adjust the potentiometer VR301. On this deck the +6 dot was moving to the right slowly, so i make a small adjustment clockwise.


1210_pitch_mark
I then plug the turntable back in turn it on and check again to see if the +6 dot is sat perfectly still with the platter spinning and 33rpm selected. If it is sat perfectly still, i then move the pitch fader back to zero and check once more that the large zero dot is prefectly still also. If it is, job done, turn off, unplug and refit the pcb cover. If not make more adjustments, using the same proceedure above.


Tone arm set-up.

Under Construction !

 

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Kernowtronic and are Copyright © 2016
They may not be copied or used without prior permission !