Ls400 - Ucf20 - Changing Bulbs And Leds In Stereo And Ac/heater Contro

[plexus914]

Hi fellow enthusiasts, I just ripped my spare unit. I am going to change some bulbs and LED lamps. I am wondering if someone can help me out here and confirm. I want to leave it as original as possible, new bulbs LEDs for old ones that is.

I did some research and found out:

Radio LCD back light IL901 + IL902 = micro lamp 2x (8V / 0,1A / 0,8W) - soldered - bulb head is about 4mm x 9mm - clear with green rubber cap

that would be the same micro bulb as in a

GS430 - 2000 - Radio LCD back light IL951 + IL952 = micro lamp (8V 100mA)

Radio "key board" back light for the buttons = micro lamp 14x (8V / 0,06A / 0,5W) - soldered - bulb head is about 3mm x 5mm - clear with green rubber cap

The 2 bulbs for the Radio LCD back light I've already soldered out.

I did not know until now that the on/off button has its own micro bulb - must be getting real hot in there because in both units I have that same micro bulb is shot.

AC / Heater control LCD

55900B BULB, AIR CONDITIONER CONTROL....LCD back light!
OEM number: 84999-60450 (12V /  1.2W /    0,1A / 1/4 socket / 5mmx10mm- 3x - LCD screen - back light
OEM number: 84999-60460 (14V / 1.82W / 0,13A / 1/4 socket / 4mmx09mm- 5x - AC control buttons - back light

AC/Heater - key board - control lights for the buttons - clear LED lamps - green and orange - Luminous Intensity 30mcd-40mcd
Button/switch - LEDs: 5x green  - 3mm - 1.8V??? - soldered - I used 2,2V / 0,02A / 40mcd
                                  2x orange - 3mm - 1,8V??? - soldered - I used 2,1V / 0,02A / 29mcd

Not micro bulb! LED lamps!!!

Bottom line - heat and age is the CULPRIT.

TIA

[Cotswold Pete]

Filaments get hot, and then if they cannot dissipate heat they will fail quicker so after many years they are bound to go. Mind you an LED reduces in brightness due to the fact that the Diode junction gets really hot and wears down over thousands of hours. This is why we do not notice LEDs failing because they do it so gradually.

As to replacing with LED's I am always nervous of this because of the noise LEDs can create, which may upset other systems around them.

When a circuit is designed with LEDs in mind then noise regulation is generally taken into account, and fact that filaments are not constant resistance from start time to active time, means LEDs can stress other devices a little more on power up.

Someone more technical than me might say you need a shunt across the LEDs to be safe, but if this is a spare unit, might be just as well to go ahead and see what happens.