Linn Karik / Brilliant Power supply repair.

Colin called by en route to the traditional Wednesday night curry....

"Got a Linn CD player here that's not working. Can you have a look?"

Yeah ... why not.

It's a Linn Karik.

I give it some power and load a CD. It fails to read the table of contents.

It then goes dead...

A couple of power cycles, and I manage to get my disc back out...

Right, Removal of four screws underneath, and slide the cover off, praying I don't see the dreaded "Brilliant" power supply ....











Oh gawd...













These supplies were sold as an "upgrade" (because Linn ownership is all about upgrades, right?) It's a switched mode in a toroidial shaped metal box, designed to fit where the once perfectly adequate, perfectly reliable mains transformer lived...

First things first, remove the nut securing the supply to the chassis from below, and lift out the supply. Undo the mains input from the input PCB, and the output to the main chassis.

Now remove the three shiny outer screws from the enclosure. You'll notice the foam washer has been cut away here, to expose three nylon screws. This means that (unsurprisingly) someone's been here before!

Right, now a note of warning! This thing always seems to remain charged up. Be very careful not to touch the PCB's, until you've checked there's not a cap charged up to a few hundred volts waiting to bite!



You can now extract the PCB's from the enclosure. You'll need to work the strain relief grommets down their slots a little to get them free...

Instantly I noticed that familiar smell of capacitors that have been too warm :(






We now need to remove the three nylon screws from the base plate. If your foam washer is still intact you'll need to remove a bit to get to the screw heads.










You can now separate the boards. Those two large electrolytics on the right are the ones that tend to hold their charge! Discharge them before they bite!

Now change out all of the small electrolytic capacitors. All of them.

You'll need:
1 x 33uF 35v
1 x 100uF 35v
1 x 220uF 25v
1x 47uF 16v

Get quality 105 degree rated caps from a reputable supplier.

In about 25% of these units, you will find you can now reassemble and it'll work :)

This one was a little stubborn. After a bit of head-scratching, it was found that the UC3825DW controller IC has failed. A replacement restored operation... nearly...

The servo was struggling to lock, discs were prone to skipping. A sure sign of a tired optic assembly. Cleaning the lens made a marginal, but inadequate improvement. A new one (from a reputable supplier) was duly fitted, and had the player working well :)