record sensor

[jeb605]

I have a Sony PSLX5 direct drive tt. For long time it did this: when turned on and start to play, arm moves over and starts to descend onto record, then stops, goes back up and turns off, just like it would do when it reaches the end of a record. Several years ago, I took it to a local repairman. He said it needed a new record sensor part - the tt was not sensing that a record was on the platter, thus turning off. He said he replaced it, but it worked once, then same problem. The tt has not been used for 3 years, and I'm now trying to find if I could fix it DIY. Thanks for any advice on: is this the problem, are parts available, could I DIY. JB

[fscl]

I have a Sony PSLX5 direct drive tt. For long time it did this: when turned on and start to play, arm moves over and starts to descend onto record, then stops, goes back up and turns off, just like it would do when it reaches the end of a record. Several years ago, I took it to a local repairman. He said it needed a new record sensor part - the tt was not sensing that a record was on the platter, thus turning off. He said he replaced it, but it worked once, then same problem. The tt has not been used for 3 years, and I'm now trying to find if I could fix it DIY. Thanks for any advice on: is this the problem, are parts available, could I DIY. JB

Welcome to VE......

Unfortunately there is nothing in the VE library pertaining to this turntable.....

However, in reviewing other service manuals, there seem to be similar Sony sensor detection schemes, download:

http://www.vinylengine.com/library/sony/ps-x55.shtml

Owners and Service manuals are here.

From your description, it does not sound like a sensor problem..... as the tonearm lowers to the LP....... . What happens if there is no LP on the turntable, does the platter just stop after 1/2 to 1 revolution of the platter..... In performing this experiment be ready to lift the tonearm so it does not allow the stylus to get ripped off by the rubber mat.

What happens with 45s..... . Does the sensor identify the correct diameter and move the tonearm to the lead in groove drop down so the stylus kisses the single and then reject.....

The schematics for the record sensing system is shown in the service manual above along with logic and list of parts....

My guess, is the automatic return is triggering too early and not allowing the tonearm to play through...... or perhaps a dodgey transistor in the detection circuitry allowing the tonearm to move over to the correct size and drop, however, when heated, sends a false signal to the logic chip telling the overide that there is no LP on the mat and to begin autolift / shutdown process..... Or a dodgey transistor in the interrupter board pg 20 of 41 in the service manual.

If the sensor is faulty, the tonearm should not move from it's rest position and the platter will only spin 1 revolution max.

Good luck. You may want to post this in the "direct drive" subcategory in Turntables and Tonearms as there are Sony owners who may have experienced a similar situation and can give you a more detailed solution.

Fred

[jeb605]

Thanks for the input. As I have not run the unit in a while, I was "stating" the problem from memory of a while ago. I'll set it up and see what it does based on your discussion above.

[fscl]

Let us know what you find, there seem to be other same model tts in the "new" Sony manufacturer area with similar problems. Makes for easier search of Sony related tts.

For interest:

viewtopic.php?f=97&t=35153

When restored, your tt should sound nice.....

Good luck.

Fred