Audio Systems: car radio repair, car radio repair, dc voltage

Question
blaupunkt peugeot ti niv 2 bp8146x2419106
7 648 146 392 model the problem i have is no power when switching on at front panel no data to separate display in vehicle power seems to be all across circuit board but have noticed at eprom at one of the legs voltage seems to float from 1v up to 3v i sure it should be 5v.i have now had about 10 in for repair it seems a common problem but never seem to find fault all help would be very gratefull thankyou.

Answer
Wayne,
You should have 5 volts constant on the supply pin(8), however on the other two pins clock(6) and data(5) you will see the voltage jumping around due to the data moving in and out of the Eprom. A good quick test is to measure the DC voltage at the on/off switch contact/s, you should have 5 volts here with the stereo or off! If you do not measure the 5 volts you should take a look at the 5 volt voltage regulator.

TOM,
T&D ELECTRONICS
tdeser@zoominternet.net