"Got a Linn CD player here that's not working. Can you have a look?"
Yeah ... why not.
It's a Linn Karik.
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 :)
Groan, capacitors again... I've owned several "Active" KEF products and all failed because of placement of electrolytics near hot heatsinks and or power resistors. The latest was the gorgeous sounding pair of KEF X300 loudspeakers, these were using grotty and ghastly cheap electrolytics, dutifully removed and replaced with high temperature quality variants. All was fine for a month and now others are failing. Buggers to get into and I'm peed right off. Not sure about LINN hardware but I'll never be buying another active KEF bit of Hi-Fi ever again. Third time bitten! Anyway, enjoyed your as usual brilliant presentation MR D! Thanks!
ReplyDeleteHello,
ReplyDeleteI would like to know which capacitors you changed in the Karik ?
I have a PB whith a Powersupply Kairn preamplifier.
Thank you for your response.
I'm not sure I understand your question. The caps were changed in the "brilliant" power supply, not in the Karik itself. The caps for the supply are listed above.
DeleteOf course , this question is about the "brilliant" power supply;
ReplyDeletewhich capacitors you changed , because i think i have the same PB whith à Kairn Power Supply ?
Thank you
Kairn uses a different flavour of brilliant... see https://andydoz.blogspot.com/2019/01/linn-kairn-err-2-dont-panic.html
ReplyDeleteIf yours was retrofitted with the toroid type, the caps are listed above.
ReplyDeleteThat's worked a charm for me - took a bit of work but well worth the effort and saved me lots of cash!!
ReplyDeleteThank you
Help.
ReplyDeleteI have a Numerik that has died - Brilliant power supply.
I am told that the residual current in one of these can be lethal to the uninitiated (which I am) and whilst I can solder and 'fix' simple stuff, I am no electrical engineer and SMPS's are dangerous.
I understand about draining capacitors before touching and have the tool but I have been bitten (nearly fatally) with a defective fuse board in a house and don't have a pair of 10kv gloves kicking about!
Linn don't want to help (just sucked breath and suggested an Akurat and give up on CD's! - streaming is, well, crap to me).
does anyone know if these SMPS were / are 'standard' in output etc or are they genuinely product specific i.e. Numerik only fits Numerik.
I want my DAC back!
Richard
Hi Andy,
ReplyDeleteThanks for your brilliant advice. I have ordered the capacitors from Panasonic and the X Y from TME arrives Monday (they say). I will post photo's when I figure out how.
The small capacitor next to the large pair (image 7) had exploded (yes, exploded at the base).
I am going to change out the lot including the XY.
Next I will check resistors etc.
If they are out of coded spec I will bin them too.
Contrary to the bull on the net, all the caps are 105c rated. Not an 85c to be seen.
I am still chewing a brick over being told to give up, spend 9.5k for a streamer and get rid of my old analogue kit by a major Linn dealer.
Made me think back to the Quad system from my mate Pete Dove, he was desperate to sell me it (he was a mate of Peter Walker), he was buying the all singing and all dancing latest (after he reviewed if for one magazine or another).
The speakers were the 57's you had along with the 22 2 11's etc.
If only my first wife had realised, all fully maintained by Quad £300.
No crying over spilt milk.
If the fix works I will let you know, if it doesn't, it's back to the drawing board to the find a Numerik lll.
Thanks again
Richard
thanks. your information has just saved my linn wakonda.
ReplyDeleteper a. jensen
Excellent work :)
DeleteHi, fixing my PSU, your note reminds me I have the same problem with the HOP3M laser, I've looked everywhere for replacement, other than dodgey chinese ones, where did you get yours from...?
ReplyDeleteMaple audio. May still be Chinese, but at least you have comeback! Don't forget to remove the blob!
DeleteAt this stage, you have nothing left to lose, you may get a few months skip-free use by *slightly* increasing the laser current. Don't go too far, otherwise it'll be destroyed instantly.
DeleteThe blob...?
ReplyDeleteThere's a solder blob on the new optical ass'y across two traces, so the receiver doesn't get screwed by static during installation. All new optical ass'y have one somewhere ...
DeleteVery helpful - thanks!
DeleteHello, I have this “brilliant” PS in my Karik. It won’t turn on, just a few blocks of the green light, then nothing. I followed your advice, and found some capacitors that just slid right off their posts, as if insides had liquified. One of them was leaking a brown liquid. Anyhow, the problem remains. Curious what your next suspect would be? I noticed the yellow paper capacitor thing (labeled 0,15uF x2, 2x4700 pF Y) has a crack near the top, so is not airtight. Not sure if that could be keeping the Karik from powering on, but wondering if anyone knows where I can find the part number for that? Found part PZB300MC23R30 at Mouser, but my part has PZB 300 MC on its side, Mouser part doesn’t have the MC at the end.
ReplyDeleteYour yellow cap is a suppressor , it contains 1 0.15uF Class X2 cap across the mains input, and 2 4700pF Class Y caps. Your mouser part seems correct. It should certainly be changed (they stink when they fail!), although I doubt it's causing your fault. Have you changed the rest of the electrolytic caps?
DeleteHi, yes, I’ve changed the electrolytics aside from the two large ones. I removed one and it tested ok, I think. 300uF and ESR of 0.022. I also installed the new suppressor. Should I replace those two remaining large caps electrolytics? I can’t really find any information on these things, so I don’t know what else to try. Any idea if it’s possible to just buy a non-brilliant drop-in replacement?
ReplyDeleteThose caps sound OK to me... does it work off-load? No idea if you can buy a replacement ... probably , it's a linn, and it's all about upgrades ... right? ;)
DeleteHello my karik stopped working, something in the power supply had leaked brown liquid, it was sent for repair the person cleaned it replaced the caps you have listed and the Rifa filter/suppressor, but he states when powered up it was at twice the voltage he normally gets on these units and decided it would be too expensive to carry on. Have you any advice
ReplyDelete, thanks
Something is awry in the feedback loop.
Delete