Hi,

my KN-3500 won't boot up anymore. The display lights up, that's all, basically.

Anybody had the same problem? I suspect one of the (e)proms may have gone bad.

Any ideas? Thanks in advance.

My KN7000 acts in a similar way.

Sometimes, the blue light on the SD board lights up, but nothing else.

I turn it off and on again and it usually works OK.

I wonder if a complete reset of the Operating System (Alec can tell us how to do it) will possibly solve the problem.

Larry G

first step try holding down 8 Bt 2, Jazz Rock & Soul and Dance Pop and switch on.

Tried that... doesn't work :-(... Another question: does a KN-3500 boot without the hard disk expansion board installed? Much easier measuring things with an oscilloscope that way. It just seems dead now... not even an error message, only a blue screen.

Thanks again, really appreciate your help.

Certainly, yes, remove the hard drive. Next step try holding down 8 Bt 1, 16 Bt, Funk & Latin Rk and Big band & Swing and switch on and see if anything happens, but if you have no leds and only a display backlight it's looking grimmer.

Nope... still dead. I didn't pay much for it (175 euros, about $200), so I guess I'll sell some parts to break even (transformer, speakers, display and hard drive expansion board seem to be OK).

I really would have liked to fix it, but you can't win 'em all, I suppose. Reminds me of that 'dead' 21" monitor I bought for 10 bucks. Replaced the fuse... and it worked ;-).

Thanks again for your help!

Fox,
I had a similar problem with a Kn2000. I found that a sudden surge in the mains voltage had taken out a power supply.When I replaced the blown semiconductors in the power supply, it still didn't work.
The Kn2000 had multiple power supplies, which seemed to all be functioning.
What I found was that each power supply had a 1/8 watt fuse resistor that had blown from the ripple effect of overload. When I replaced all of the fuse resistors, all was well.
They are hard to find because when they blow, they do not burn or change color like a normal resistor that has been burnt.
Good Luck,
Walt

Hi Walt,

Thanks, I'll look into it. KN3500 has only one transformer, output voltage is good. I've got a stable 5V, 3.3V, and 12V. Should it have negative voltages? I'm still not convinced that the PROM is faulty.

Thanks!

Hi,
I believe that there should be a -12 volt buss if the KN3500 follows the typical design of the Technics products. I also had power supply problems with my Technics SX-xxx spinet organ and it had the same power supply setup.
Be sure that the power busses are powered up even though the power supplies are working. I seem to remember that some of the fuse resistors were in the output leads to the busses. When I find my KN2000 schematic, I can check better for you.
Walt

Hi again,
I just checked the schematic for the KN2000 and it has:


[*]+5v

[*]-5v

[*]-24v

This is probably different than the KN3500 but see what you can find.
There is also a regulator to feed dc to the circuit that provides the backlight for the display but it is unmarked.
Walt

[This message has been edited by Walt Meyer (edited 02-04-2004).]

[This message has been edited by Walt Meyer (edited 02-04-2004).]