When I switch on my Kenwood UD-70 Hi Fi the display flashed up showing "PROTECT". The manual states that this is due to a short circuit on the speakers. The speakers have been thoroughly checked out OK. The problem must lie in the fault detection circuit, as some times the system will play correctly for varying lengths of time. It has been back to a local Hi Fi repair shop, but they have given up.
Any advice will be greatly appreciated.

Trevor Angel, August 2005

Hi all,

Reading all the Posts on this blog, it seems as if there isn't a one size fits all solution to the problem. There is bad connection somewhere causing a short circuit, resulting in THE PROTECT display.

You wil need to disconnect every device from the amplifier and start adding them back one by one. At some point you'll notice the PROTECT message: then you know which device is causing THE problem.

What I did to fix it was:
- clean and firmly reconnect the outer connection
- open the affected device (in my case the equalizer) and pushed the inner connection as well

That fixed things for my UD70.

Hope it helps.
Regards,

Pieter

Pieter Biesemans, December 2010

this problem is due to an output ic which is available from FULLERS 01728746500 . The ic is poss an stk ic

bob, April 2010

have the same problem,the protect message does not appear
when the equaliser is disconnected,tried all the ideas mentioned in this page but nothing has worked,any other ideas?

martin Hayes, November 2008

I had this problem. I checked the speakers, they were fine. I then disconnected the cd player and this solved the problem, I was then able to use the tuner and cassette player. I then cleaned the cd connection and plugged it back in and it now works fine. It sounds simple and I hope it solves the problem long term??

poggle the lesser, June 2008

As I discovered after much headknocking: simply check out pg. 64 ("In Case of Difficulty") of the UD-70 manual. Under "Receiver, Speakers" you'll read that your have short-circuited your speakers by misconnecting their wires. See "Connection of Front Speakers", pg. 11, for correct procedure.

Dave Keller, February 2008

I have exactly the same problem with my ud 70. I have disconnected everything and the tuner appears to work fine (without the PROTECT message) albeit I cannot hear anythingm even with the speakers connected. As soon as I connect the equiliser, I get the PROTECT message.

Any ideas?

fra, November 2005

NB. Quick check for o/c tweeters or mid range drives...
During a period where it will function, remove the front clip on cloth cover to expose the speakers & cup your hand over the suspect tweeter or mid-range cone then remove your hand, you should hear a distinct change in tone. If you don't hear a change, the speaker is o/c.

Cobweb, September 2005

I'd still double check that your tweeters have not gone open circuit.

Cobweb, September 2005