Krell Kps 25 sc problems

[Cognard]

Hi Pals ! i am new to this forum , this is my first post .

i have a Krell kps25sc that i bought in non working condition , problem seems to be on the cd transport , laser keeps ticking up and down against the cd hub. then goes to the left , then keeps ticking 20 times , then to the left and so on ..... , contacted Krell , they sent me lots of schematics , except the ones that drives the cd transport .....anybody out there willing to help me out ? i have even bought a new optima 4 laser assy ...


thank you !!

Rick

 

[Steve Williams]

why can’t you send it back to Krell.
I owned a KPS25SC and it was one of the best pieces of equipment Dan ever designed.

 

[Cognard]

Becaaaaaause .........i am in Argentina and the unit weighs 60 pounds , it is extremely fragile and heavy to ship ......

 

[Steve Williams]

Becaaaaaause .........i am in Argentina and the unit weighs 60 pounds , it is extremely fragile and heavy to ship ......

Shipping is easy. That’s far from heavy. I would ship it to Krell

 

[Cognard]

Shipping is easy. That’s far from heavy. I would ship it to Krell

forgot to inform you .....we will have to pay 50% of duties at the time of return , no matter if the unit is newly imported or returned from service .

 

[Steve Williams]

forgot to inform you .....we will have to pay 50% of duties at the time of return , no matter if the unit is newly imported or returned from service .

Well how else can you get proper parts to repair it. They can also issue an invoice showing low value of the unit as it is over 20. Years old

 

[Lagonda]

Rick, so the new laser did not help ? Did you get it from the Argentinian guy i had gotten my spare laser from ? The expert in Holland has one machine from each generation in working order and maybe he can help you. He might be able to do it if you ship him the appropriate board only. I tried to help you on Audiogon.
Here is his website:

Creato

www.creatoaudio.com

P.S. Click on the name. For some reason our shared links are not shown as links currently.

 

[Cognard]

Well how else can you get proper parts to repair it. They can also issue an invoice showing low value of the unit as it is over 20. Years old

we can fix it if we have the spares , we can even buy them in the US, these will be much cheaper to ship down here ...if they are not already at any shop locally

 

[Cognard]

Rick, so the new laser did not help ? Did you get it from the Argentinian guy i had gotten my spare laser from ? The expert in Holland has one machine from each generation in working order and maybe he can help you. He might be able to do it if you ship him the appropriate board only. I tried to help you on Audiogon.
Here is his website:

Creato

www.creatoaudio.com

P.S. Click on the name. For some reason our shared links are not shown as links currently.

laser has not been installed yet , i have got it from another guy , it was the last one available .....there are just a motherboard , a cd transport board , a power source board and 3 audio boards on the right .......shouldn`t be hard to spot the problem

 

[Lagonda]

laser has not been installed yet , i have got it from another guy , it was the last one available .....there are just a motherboard , a cd transport board , a power source board and 3 audio boards on the right .......shouldn`t be hard to spot the problem

First time mine had problems, changing the laser fixed it. Just be careful installing it, any burst of static electricity can destroy the new laser. Second time i had problems the new laser was bad, and i ended up changing all the capacitors on the control board before realizing the new laser was bad. You can start by turning the power on the old laser up before changing it, sometimes that helps. Don't adjust the dials on the control board, they are hard to get right again if you do.

 

[Cognard]

well , fixed my KPS25sc already , rf amp and motor driving transistors with cold solderings were the culprit here ......no need to change the laser .......just one detail that still makes me thinking about some problems .......the unit takes 4 to 5 secs to start the next song when i press the forward button , and sometimes it gets back to the previous song .....this is not normal i see..... the new laser i installed makes exactly the same drill .......any clue ??

 

[Lagonda]

well , fixed my KPS25sc already , rf amp and motor driving transistors with cold solderings were the culprit here ......no need to change the laser .......just one detail that still makes me thinking about some problems .......the unit takes 4 to 5 secs to start the next song when i press the forward button , and sometimes it gets back to the previous song .....this is not normal i see..... the new laser i installed makes exactly the same drill .......any clue ??

Is it reading TOC ( table of content) when it starts up on a new CD ? If it is not, it will not know where the individual tracks are located and the laser will start searching. It has to do with the sensors in the lid assembly, if they are not working properly it will use TOC from last read CD even if you place a new CD on the drive. Try manually turning of the power on the back toggle switch when you place a new CD, this will reset the TOC content and force the drive to read the TOC of the current CD.

 

[Cognard]

sooooo every time i put a new disc will i have to turn the power off ??

 

[Cognard]

did that , it still makes the same

 

[Lagonda]

did that , it still makes the same

Sorry that did not work, have you lubricated the two steel rods the laser rides on with a thin oil ?

 

[Lagonda]

sooooo every time i put a new disc will i have to turn the power off ??

Only if the lid sensor is not working.

 

[Lagonda]

If someone has adjusted the 4 dials on the laser control board, it could be reading wrong in some locations on a CD. Does it have problems with all CD's ?

 

[Cognard]

one sensor cable was detached , i have used a cheater to operate the unit without the lid on , i will rewire , check the sensors and re test
most cd players resets the TOC when the stop button is pressed ..this deffinitely resets the toc when the hub is removed .....i will post the outcome soon ....

 

[Lagonda]

one sensor cable was detached , i have used a cheater to operate the unit without the lid on , i will rewire , check the sensors and re test
most cd players resets the TOC when the stop button is pressed ..this deffinitely resets the toc when the hub is removed .....i will post the outcome soon ....

This machine needs a sensor signal or power off to reset TOC, pushing stop is not enough Good luck !

 

[Cognard]

looks like the problem was fixed , i will install the lid tomorrow and test , but the problem was there ( sensors and hub )