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Thank you. have ordered them.

Yes, tone arm does affect tp4. Goes from 7.1 v to about 5,5v The voltage drop seems about right but the voltage is a bit high should be 4.4v dropping to 2v I will order some bits and replace the defective ones found earlier and maybe all will be ok. Diode needed is a EQ A01 13R. Any recent...

Thanks for replying. I will have a look later today. I have found a couple of faults elsewhere on the board which need to be rectified. D104 zener diode is open and R125 100 ohm resistor attached to it is down to 36 ohms and getting very hot. Thanks very much for your help.

I have been trying to repair the above turntable for some time now. There are a lot of voltages that are wrong in areas of the board. At the moment I am trying to figure out the potentiometer RV 201. In circuit it seems to measure about 20k in any direction but having pulled it it measures 53k...

I have been trying to do this one on my own but soon realised I am out of my depth. I am trying top repair a sony PS 4300 direct dive turntable. I bought it as a non runner in the hope of repairing it myself. A previous owner has recapped it and it looks a competent job. I have started to get...

Agreed. The best !

Thanks for that, it's not on my schematic well done for finding.

It's a Sony ps 4300 turntable. motor does not start so trying to work through the board. Just never come across these bracketed figures before. For example the (1.3v) figure at the base of Q 201 there I cant seem to find, tried pushing buttons etc. Many thanks.

From a Sony turntable

On a schematic and there are 2 voltages quoted (one below in brackets) does that mean it would be this voltage under certain circumstances i.e if a button was pushed or some other meaning. Thanks for any help .

I think I have been measuring this wrong. I was using turntable ground and not the black wire. DC volts blk to red 7.26 blk to violet 22.4v Blk wire to D303 7.91 Looks like power supply ok then? problem must lie elsewhere. Many thanks for all the help. Much appreciated.

Just pulled the diodes and all check ok and orientation good. caps replaced with known good and correct orientation. Is it likely voltage regulator bad?

Thanks for your reply, the board seems unmarked as for cap orientation. It all looks good, no sign of heat damage. I gave an AC figure as DC is just millivolts and pulsing as if AC? I am thinking someone has got the caps in wrong way? would that do this or am I way off here?

I have a Sony turntable that has a non working motor. . I think it is the power supply board but of course I may be wrong. I have 37.5 v Ac on all pins of Q301. Someone has replaced the capacitors so may have got them in wrong? Any suggestions gratefully received. Thank you.

Caps shouldn't make much difference unless originals badly out of spec. Did you get polarity correct? I.m sure you did. I find these problems are mostly dirty switches and contacts. clean everything. Good luck.

I would look at the schematic to find the fusible resistors and replace them . They go way off value over time and cause issues.

Thank you for posting this, I have a Sony CDP 470 cd player that will read some discs but not many. It has been unused for many years. Any ideas what could be wrong I have cleaned the lens. Many thanks

Well I have made some progress. Other than finding one slightly dirty ground point on the tonearm I can find no fault at all. But... I tried a temporary wire between the tonearm and the amp grounding point and the noise totally disappeared. Also the noise goes if the turntable is powered off. I...

I may have found the problem, the tonearm to ground wire shows no continuity unless you put some pressure on the probe. I am thinking that it may be partially grounding through the bearing and the groundwire may be broken in the arm. So I will have to strip the arm down and have a look. As...

The wire was disconnected from the terminal but the meter was put in series between the 2 points. I guess this is not the way to do it? The noise I hear is mostly from Led lighting and power adaptors I think, It is a fairly high pitched buzz this is worse on one of my older ampliiers and not so...

Thank you for your reply, ground wire was disconnected.

Thank you for such in in depth answer.You really do know your turmtables!! I think I did measure the voltage and amps as you describe and the meter is autoranging. So it seems what I am seeing is a feature and not a fault and I need to keep looking for the problem elsewhere. I have checked the...

I measured in series one probe on ground wire and one on amp chassis.

Hi, I have a Tchnics SL1410 MK2 turntable which is direct drive. A while ago I noticed noise coming through the speakers which sounded like interference of some kiind. I have been trying to find out the cause and today I thought I would check to see if there was any voltage on the TT ground...