mark66

Hello,

Hoping someone can help. Can't seem to find a thread with a similar problem.

Just picked up a 1996 LS400, (89,000 miles), and having some issues with the Nakamichi head unit. Most of the buttons on the stereo work only part of the time. The volume **** seems to always work for on & off and volume control. Also, the radio will randomly start to scan stations by itself. Weird.

Plan on replacing the unit soon but have a road trip in a few days and won't have time. Hoping there is a quick fix before I hit the road.

Thanks in advance.

Mark

timmy0tool

iTrader: (7)

I suspect the contacts have deteriorated or there is gunk in the buttons causing unintentional pushes (stuck). does the button have smooth tactic feel, or a bit crummy and loose?

Yamae

Things are not always very simple. You'd need to check the ripple voltage at the processor's Vcc line and the switch lines. When it is more than 100mV, switches can't work properly. You need to reduce the ripple. One idea is to replace electrolytic capacitors used at the processor's Vcc line.

mark66

Thx for the response. I took the unit out and cleaned what I could with contact cleaner. Seems to be working for now.

Yamae, thank you for your response. I think your suggestion may be beyond my skill set. I have a double din head unit to replace the factory unit, just need to dedicate a day to rewiring to bypass the amp.

Thnx again.