Sony Ps-x75 Important notice re Main MicroProcessor MB8841-209L

[brinsmead]

If you own a Sony PS-x75 and PS-x65 turntable that doesn’t respond to the push buttons and there is no motor function and power supply voltages are within tolerances

There is a good chance that the 4bit Fujitsu micro processor,
MB8841-209L is faulty. Original Sony Part No…….8.759.982.09
This original Sony encoded IC ( Fujitsu was discontinued in the late 80’s )

Sony advised that in 1991 substitution handbook that this IC was to be replaced
With: Fujitsu……….
MB8841-327L……….. Replacement Sony Part No……….8.759.983.27

There are a number of these for sale in GB on ebay at this time
These micro processors do have a high failure rate and many Sony PS-x75 and
Sony PS-x65 have been dismantled for components because of these
IC’s being unavailable.

 

[brinsmead]

Sony PS-x75 Important Notice to repairers

Also absent in the display will be the word ‘Locked’
And ‘33’ will not change

 

[daniel thoma]

Thank you very much! This is very helpful information for Sony Biotracer fans. I've noticed that the PS-X75's have developed "old age" problems in recent years, and as we all know, repairing the computer parts can be tricky.

I haven't heard of the later Biotracer models (X600, X700, X800, X555es) having these issues, so perhaps better computer chips were used? I'll be sure to keep my eyes open if anything happens with my deck. Thanks again!

 

[Kim G]

I ordered one this morning and I just now received this message from the seller

"Hi,

Thank you for your order.

After review, i am not too convinced the quality of these IC's are up to scratch.

We have no delivery date for new stock, so i have no choice but to issue a full refund.

The listing is now removed from ebay.

Please accept our apologies.

We hope to serve you better next time"


Well I had hope for a little while.
Sitting on a PS-X65 boat anchor.

 

[brinsmead]

Sony PS-x75 4 Bit Processor

Thankyou, Daniel for those words.



Interesting that there was one for sale in the US (sony packaged) on EBay recently

So they do pop up from time to time

 

[brinsmead]

Follow the yellow brick road..........heres the Fujitsu 4 Bit IC in the US
All sold

 

[Kim G]

Thanks for the lead. I just bought the last one.

 

[brinsmead]

I'd like to thank Vintage (of this forum) for his sincere help with the purchasing of one of these.

 

[Vint Age]

I'd like to thank Vintage (of this forum) for his sincere help with the purchasing of one of these.

My pleasure Brins. Hope it gets your PS-x75 back up and spinning like a top! :thmbsp:

 

[Cobra2]

IC: MB8841-327
http://www.dalbani.co.uk/catalogue/product_details.php?id=19750

Arne K

 

[brinsmead]

A very special thankyou, Vintage it's spinning again, beautiful

 

[brinsmead]

Mb8841-327

USA owners of Sony PS-x75
Sears do have stock of the MB8841-327 as of Dec 2013, albeit pricey of $79

 

[brinsmead]

A point to note about fitting the 42 pin MB8841-327 is that if you feel uncomfortable about soldering in this IC on to the PS-x75 main PCB, another option is to fit a 42pin DIL socket (with gold contacts preferably)

 

[Vint Age]

A very special thankyou, Vintage it's spinning again, beautiful

:thmbsp:

 

[mallikh67]

sony ps-x75

:thmbsp:

hi

this is mallikh from india and i have an mint sony ps-x75 ttable and the main

ic mb8841-207 or mb-8841-327 is dead.any one can source this ic for my

ttable,

 

[franimal007]

Who can do a nice job servicing the Sony PS-X75????

 

[brianjrealto]

For those of you that have a bad IC chip (MB8841-209L), there may be some hope...

I have a PS-X65 which is also controlled by the same IC Chip as the PS-X75 Biotracer. The IC chip failed/burned in my X65 as a result of the power supply caps going bad....wish I had caught it in time. I was left with a "dead" turntable with no replacement chip to be found...

But, a tech friend of mine has been working on a substitute for the IC chip using Arduino/Teensy technology. It has been a work in progress as this is new territory implementing new technology to replace old. But, this is very possible.

after several weeks, the good news is that a Teensy ++2.0 is now sitting in place (using a pin socket and pinout wiring) where the original IC chip was. With some basic programming code uploaded to the Teensy, some of the basic table functions are now working. So, the "dead" table is now showing signs of life again...

At this point, it's just a matter of figuring out the remaining programming code to mimic the "conducting' functions of the original IC chip. this may take some time translating the flow chart of the schematic into proper programming language to upload in the Teensy. But, my tech friend is well-versed in the different programming languages and should have it figured out in the coming weeks.

I will post some pics and report back as things progress...

 

[GrampaDave]

Outstanding! I love modern prosthetic solutions for unavailable old parts. I will monitor this thread.

 

[gekeller]

For those of you that have a bad IC chip (MB8841-209L), there may be some hope...

I have a PS-X65 which is also controlled by the same IC Chip as the PS-X75 Biotracer. The IC chip failed/burned in my X65 as a result of the power supply caps going bad....wish I had caught it in time. I was left with a "dead" turntable with no replacement chip to be found...

But, a tech friend of mine has been working on a substitute for the IC chip using Arduino/Teensy technology. It has been a work in progress as this is new territory implementing new technology to replace old. But, this is very possible.

after several weeks, the good news is that a Teensy ++2.0 is now sitting in place (using a pin socket and pinout wiring) where the original IC chip was. With some basic programming code uploaded to the Teensy, some of the basic table functions are now working. So, the "dead" table is now showing signs of life again...

At this point, it's just a matter of figuring out the remaining programming code to mimic the "conducting' functions of the original IC chip. this may take some time translating the flow chart of the schematic into proper programming language to upload in the Teensy. But, my tech friend is well-versed in the different programming languages and should have it figured out in the coming weeks.

I will post some pics and report back as things progress...

Hi Brian, Were you able to get a replacement for the MB8841-209L microprocessor working? I have a PS-X75 that I bought in 1980 and I would love to get it working again. Thanks in advance for any information you have.

 

[brianjrealto]

It's been on the back burner with my tech friend all this time. It could be done but its just tedious, from what my friend says. I wish it were finished, that way others could benefit from ardueno technology in place of the IC chip. Im sure there are others out there with the same dead chip problem, longing for the day it would spin again..