Technics SL-1200 Stylus Illuminator LED
I own a couple SL-1200MK2’s for which I want to replace the incandescent stylus illuminator bulb with LEDs. I was able figuring out the circuitry from the SL-1200MK5 service manual. However the OEM blue LED (RXQ1012) is over $15 which defeats the purpose of replacing the light bulb in the first place. Therefore I was looking for a cheaper equivalent LED but could not figure the voltage and current. Does anyone have the specs of the blue LED?
Just go to radioshack and get a 5mm LED, it will have the specs on the package so you can choose the right resistor.
I read somewhere that the voltage coming off of the main board to the pop-up is 20v, but after testing myself, i got 21.5v.
Thanks for the response. However I am not sure that will work as the circuit of the MK5 is a little more complex than the previous models; it has a Zener diode mounted in reverse-parallel with the LED (the anode of LED connected with cathode of Zener, and vice-versa), assuming the Zener’s purpose is regulating the voltage. There is also a couple of half-watt 2.2k resistors mounted in parallel (I would assume the aim is getting 1.1k, 1watt). I have seen posts and videos about replacing the lamp with a LED and it doesn’t look like it’s just a matter of placing a resistor in series with the LED, which is the reason why I am looking for the OEM LED specs; I don’t want to blow the main circuit board…
I guess i misread, i thought you were putting LEDs in the mk2?
I think if you know your voltage coming off the mainboard, and are savvy with electronics, a voltage regulator and resistor could be done with just about any LED.
Are you looking for the specs just to get the right brightness or what?
If you have mk2’s i would advise you to buy two 3mm LED’s bend them at a 90 degree angle so the brightness shines onto the record and the resister should be averagely 1k ohm or 1.25k ohm..
Hope this helps. As i have just done it to mines.
You read right; I do want to replace the bulb of my MK2 by an LED. I just wanted to use the Mk5 design to make sure I don’t blow up the main board. The Mk2 and Mk5 roughly have the same voltage (20-22volts). Like I said I am looking for voltage and max current so I can find a similar LED…
You just put the resistor in series with the LED? Did you leave the original 1.5k resistor which is soldered on 2 poles of the switch?
Are yours MK2’s?
Yes mines are mk2’s, and i replaced the resistor with a 1k ohm resistor and replaced the original lamp with a 3mm LED (3V) and bent it 90 degrees. Haven’t got any pictures yet as i haven’t assembled it all back together properly as i’m now working on the pitch fader and 33/45..
Oh and i’m an electronics engineer by day.
Thanks for the feedback. However looking in the Mk2 service manual I see that the 1.5k resistor is mounted in parallel with the switch. So when the switch is at the closed (on) position it short-circuits the resistor. Hence if I just replace the lamp by the LED it will not be protected which I believe would blow the LED and damage the main board… Am I missing something?
Sorry you are correct on saying that, if you don’t have a resistor that is parallel with the LED or none at all and you try to switch it on you will just blow out the LED 
I think I figured it out… The Zener does act as a voltage regulator. Hence I guess it is just a matter of matching the LED with the Zener voltage of diode (or vice-versa). For instance, the Mk5 Zener voltage is 5.1volts (MAZ40510M) so I guess it would be safe assuming the LED voltage in more or less 5 volts. Here’s the actual circuit…
Just go to radioshack and get a 5mm LED, it will have the specs on the package so you can choose the right resistor.
led strip lighting
led strip lighting outdoor
12v led light bars
I’m trying to replace the pop-up light on my mk2 with an LED too, I was wondering if you guys figured out what components you needed to accomplish this. Did you ever get the LED working?
Done it hundreds of times. 5mm will not fit in the lamp tube very well. Use 3mm LED’s bend them 90 degrees and add heat shrink to the legs once you have soldered the wires on. You will need to put a resistor in series with the LED to stop it from blowing due to over voltage. The 1200 MK2’s spit out 20 - 21vcd for the pop up lamp.
Use this calculator LED Resistor Calculator to work out what resistor you need. The resistor value will vary depending on the LED specs. Note you need to wire the LED/s in parallel.
Last but not least you need to clip off the resistor on the lamp switch.
If the LED doesn’t light after you have wired it up you most probably have wired its legs ass about. Swap the wires and you should have light.
The components and heat shrink will cost you approx. $5 per deck. It’s an easy job just take your time. A quick tip is discard the globe and the white plastic globe holder. Have fun
Ah no wonder my pop up lamp looks dim…i forgot to bend them and now it has been installed.
hmm…too lazy to unscrew the base just to get to the pop up lamp again…is it possible to try using long thin object to do the bending from the outside?
Nice tips man
this is somehow related to the topc, please any help is welcome
HELP PLEASE!
I was replacing the stylus lamp for the regular technics replacement bulb, just by cutting wires and joining them with the new bulb wires, and accidentally the two cables touched and the turntable went off. It is not turning on since then and I can’t find the fuse on it, any help? any advice?
Thanks a lot!
nope, mine is an older version, it has no fuses, i’m prety much screwed so far, almost 3 weeks past and i’m still dwelling with this bull crap… please heeeelp
Let me guess, an old 1200 ?
Please post picture of main circuit board & what are you voltage readings now (transfo) ?
My first assessment says change the power transistors Q2 & Q3 (NTE16)
You could always PM ‘Nicadraus’…he is a real wizard with Sl’s
Stay calm, you really have to screw something up to kill a SL, it’s only wounded now
Ps. make SHURE the needle lamp wires are not shorting again !