|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
4.241.0.147
In Reply to: HELP PLEASE - anyone with technical experience with Technics SP series? posted by M3 lover on September 14, 2006 at 16:34:57:
The built-in strobe shows stable and correct running at all three speeds. When I set up the table on a temporary board with tonearm to audition, speed was obviously off. This was when I used an external strobe disc on the platter which indicated it was running fast at all speeds.
Follow Ups:
Since the strobe runs on the same crystal as the motor drive it will not show changes due to crystal circuit errors.Check the waveform at pin 5 of IC3 on the logic board for correct period (1.14 us). If it's off, adjust trimmer C210. If it's right, check pin 1 of IC5 and so on.
Mark, thanks for responding. I'm not too technical so will need to relay your suggestions to my friend who is. Therefore, I need to be clear on your recommendationsFirst, did you note I have a Mk 2A, not a Mk 2? As I understand it, they are quite different. Looking at the Service Manual for the 2A, no IC3 or IC5 is shown. All the ICs have 3-digit numbers: 10?, 20?, 30?.
If this helps, the frequency to IC301 was verified at 273.30 as specified. So, what next?
I don't have acess to a manual so I can't help.
This post is made possible by the generous support of people like you and our sponsors: