SL1210 MK2 Intermittent pitch problem

[Scotty1210]

Hi All

I hope im posting in the right place,Im new to this forum so please go easy on me...

I have a problem with one of my 1210's.

The turntable has been sitting for about a year or two due to the fact that it would turn on at all so after some investigation, I found that the wire for the target light was very close to snapping inside the pop up unit so i just removed it all together thinking if its not there than it will be fine and it was for a few weeks then this started.......

When i turn it on and press the start button, it starts as it should but then the pitch speeds up intermittently then back..all within say 5 seconds and then starts again,the red dots by the on/off switch are all over the place and the pitch increase/decrease is very noticeable over the sound system i have.
the pitch fader is in good condition and i have checked for any other shorts but cant find anything..

Im fairly able with a soldering iron and multimeter but even so im still abit stuck for info on how to sort this problem.

Any info will be greatly appreciated.

 

[Zen Mod]

well- I'll try to guess - usually when power wire for target light snaps, touching case - main regulator transistor is in danger ;

probably that transistor in your TT is damaged from that reason , and he's acting funny

check Q1,Q2,Q3

Q1 is 2SD1265 - under the clamp on metal part of case , and Q2 and Q3 are little ones on pcb - you'll find them looking at overlay on pcb .

both are 2SD637

check also D1 , which is 5V1 zenner diode .

in case that you are not able to check that by your self , find a tech .


edit :

you must see 21V6 after Q1 emiter
do not power up TT without platter ;

OK - you can power up it without platter , but be careful to not press start without it