audio-talk

Hi Nick, thanks for that, so that I don't do any more damage using the scope, which points do I use to test the 50K oscillator? C1 or C2 for the probe and ground point for the ground. I will get stuck in tomorrow night and get back to you with a whole pile of results. heres hoping.

Hi Nick, I dont know if this is significant but I notice when I press the button to start the platter spinning, I notice a couple of things. 1. the driver transistors get very hot very quickly. 2. the strobe light goes out completely and when you press the button to shut it off the strobe comes back...

HI Nick, I still have 32.5 volts, the reason I say that is the plunger for the brake still works fine, you can hear the clicking every time you press the on/off button. All of the voltages appear to be OK. To be sure I will measure them again tonight. Thank you for being patient.

Yes I do, it is etched into my brain. I used the ground probe of the scope onto C1 and the main probe onto C2 of the drive board. I was trying to measure the waveform of the 50K oscillator circuit. AS soon as I did that, it blew a fuse and that was it. I feel like a complete fool.

Hi Nick, I have just about completed testing all of the transistor and diodes. I will send you the list. I am also taking measurement of all of the IC chips from each pinout. I have also got a full compliment of transistors and IC's to replace anything that is faulty. I am ready to go but not sure w...

Hi Nick, I worked out how to bring the SP10MK2 to original format. The ABC mod was just for the cueing of the deck. It is back to original. Now I am still trying to get it going. I replaced all the IC chips but that made no difference, the driver transistors are still getting very hot and there is n...

Hi all, still trying to get this thing going. I am trying to follow the flow chart to find out where the problem is, I got to the point where I have to check the voltage at P3, at this point, I am only getting 4.6 millivolt instead of 0.7 of a volt. It then asks for you to check IC 1 voltages and th...

Hi Nick, I certainly did, and I have spares of the chips, so I will start there. I checked the Crystal oscillator last night and that seems to work OK 3.579 mega hertz. How do I test the other oscillator circuit? the 50K Hertz circuit using T1 and Tr28. Just out of left field, can one return the SP1...

Hi Nick, how do I test the motor to make sure I have'nt destroyed it? I did put the multimeter on ohms and measured the motor from AC to A1, AC to A2 and AC to A3 they all read 14.5 ohms across them all, is that OK or have I destroyed the motor. If that is OK, then I can sigh with relief and continu...

Hi Nick, I dont know if you read my last post, but I have had a massive fail, tried testing the 50k herz oscillator circuit and something went pop. blew the 32.5 volt fuse and all I get now is the solenoid for the brake clicking. Nothing else apart from the main driver transistors getting real hot. ...

Hello to all SP10MK2 owners, I finally got mine running but had problems locking onto speed, so in my haste I tested the oscillator using C1 and C2 on the drive board, bang, 32 volt fuse popped, replaced fuse and all I get is the clicking of the brake solenoid. Platter doesnt spin, I have put some o...

Hi Nick, the SP10 Mk2 that I have has been modified by the ABC in OZ. I will attach some more photos.

Hi Nick, will try sending a couple of photos.

Hi nic thank you for taking pity on an old fool. I would like to send you an image but every time I drag the image accross , it tells me the file size is too large, I tried zipping but that didnt work either. Can you tell me what size file I can send

Regards
Wolfgang

Hi Nick, tried a 1.1K resistor in parallel with the 4.7k, unfortunately it didnt make any difference. I dont know if I mentioned it before but I am a Plumber not an electronics engineer. I have been struggling to get some of these waveforms that are in the service manual. I have a pretty good knowle...