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Re: SP10 Troubles

Posted: Sun Dec 09, 2018 12:01 pm
by Nick
If needed, host them somewhere else and just supply a link. If you are going to post scope traces, get your scope to dump to a usb stick and send the images from that, no need to see the entire scope.

Re: SP10 Troubles

Posted: Tue Dec 11, 2018 1:10 pm
by Wolfgang Felber
Hi Nick, the SP10 Mk2 that I have has been modified by the ABC in OZ. I will attach some more photos.

Re: SP10 Troubles

Posted: Tue Jan 08, 2019 3:53 am
by Wolfgang Felber
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 of my measurements down below. Appreciate any help.

A3 & A4 the field generator coil measured 264.64 ohms
The motor windings each gave a reading of 14.1 ohms, that was from common to each of the windings
The voltage coming from AC to A1 was 0.625 volts or 625 millivolts
The voltage coming from AC to A2 was the same.
The voltage coming from AC to A3 was only 115 millivolts, is there something wrong there?
I also noticed that the heat sink was very hot, I could not pinpoint which transistor was causing that amount of heat.
I also test the MA150 diodes, d11 was giving a good reading of 0.625 millivolts from one side which was common on all the MA 150,s, the difference with D11 is that reversing the leads on the other three gave a reading of 1.125 volts where D11 was OL. Does this sound like a faulty diode. These I believe can be replaced with IN4148 diodes from Jaycar. I tested all the resistors and they were OK.
My next step will have to be testing all the transistors which is going to be a long job.

Open to suggestions.

Re: SP10 Troubles

Posted: Wed Mar 06, 2019 10:25 pm
by Wolfgang Felber
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 they are as follows:
1 4.15 volts 2 42.1 milli volts 3 4.34 volts 4 4.17 volts 5 42.1 millivolts 6 4.33 volts 7 4.5 millivolts 8 4.51 volts 9 4.34 volts 10 150.3 millivolts 11 150.3 millivolts 12 4.51 volts 13 4.33 volts 14 4.89 volts.

I then tested the transistors tr201 - tr204 and they read as follows: tr201 base 0.667 volts Collector 50.1 millivolts Emitter 4.5 millivolts
tr 202 Base 27.3 millivolts Coll 4.16 volts Emitter 4.4 millivolts TR 203 Base 4.5 millivolts Coll 4.16 volts Emitter 4.5 millivolts TR204 Base 0.678 volts Coll 42.2 millivolts Emitter 4.5 millivolts.

It then asked to check the drive board Transistors TR 39 - 41 and they read OK all emitters are joined and read 20.26 volts the base all read 19.48 volts.
I am hoping that maybe Nick, who seems to know most about this machine can give me some more of his knowledge. thanks to all for their input