RC-1090 "CD" source hum

[cfrahme52]

My 6 year old RC-1090 preamp started producing a very noticeable hum after swapping CD player interconnects the other evening. The hum appears when "CD" is selected as a source and there is a component connected and powered on.
Gently "wiggling" the cables produces mild static.
I can hear music being reproduced through my speakers, but the hum is more prominent.
I swapped cables again and the hum remained.
No hum with LPs w/ "PHONO" and I connected the CD player to "AUX1" and pristine sound again.
Of course, my unit is out of warranty and will cost $75 min. to be repaired by
B & W group in MA.
Anyone experience anything like this and attempt home repair?
I welcome any suggestions and further information.
Thanks!

[Glen B]

A possibility could be a loose/bad connection to the outer sleeve of the RCA jacks for the CD input, either at the jacks themselves or at the PC board. From recent threads here of late, it seems like there are a lot of little problems with Rotel gear.

[cfrahme52]

Thanks, Glen.
Anyone have experience opening up a RC-1090?
(I've opened my RB-1080 for fuse replacement..)
I'm tempted to investigate further before shipping the unit off.
I have some stereo kit building experience (Hafler DH200 amp back in the 80's)
but have never really worked on a circuit board.
Is it hard to do?

[Glen B]

Remove screws on each side of the top cover and rear edge as indicated by the arrows in pic #2. It appears that the upper PC board (red arrow in pic #1) to which the XLR jacks are attached will have to be removed in order to gain access to the lower board (yellow arrow in pic #1) to which the RCA jacks are likely connected. You will also have to remove screws securing the XLR jacks to the rear panel before you can remove the upper PC board.

[cfrahme52]

Many thanks, Glen.
Got the cover off and had a look around.
Great photos!!
Discovered that the input jacks are paired-PHONO and CD, for example.
I couldn't find any evidence of mechanical failure in the plugs themselves.
There also was no physical movement of the RCA jacks when inserting/unplugging a connector.
Decided it's best to send it off to B&W and hope for the best.
Can keep you posted...
Charlie
BTW, I was very impressed with the build quality and layout of the interior!

[cfrahme52]

Can't say enough good things about George Miller at B&W Group in MA.
Handling return/repair in a very professional, helpful & efficient manner.
We corresponded by email & had a nice phone conversation.
His phone diagnosis leans towards a simple repair-probably a loose RCA ground. I hope so!
The only downside-a 28 day turnaround. Luckily, I'm only one shipping day away in upstate NY.

[SkyDover]

I have alot of Rotel equip. I haven't had any problems so far....keep fingers crossed.
Rotel Tech Support has always been flawless for me. When I got my RC-1090 in from the dealer, the shipping company damaged it, when I called Rotel about it, they rushed out another unit to the dealer so I wouldn't have to wait another week for it to come in.
Very easy and polite to deal with! I called and talked with tech several times when trying to learn the remote control that comes with the RC-1090 and they helped me with patients!!

[rattlebone]

I had this happen to an input on the RC-1090 twice in ten years I have owned it

Look in the RC-1090 manual and perform a reset of the unit
it fixed the problem both times

[madmac]

Hum is almost always due to grounding issues. Make sure ALL your gear is connected to a properly grounded surge protected/line conditioning power bar. If the problem perisists after that, then cables and the Rotel itself can be investigated.