S60 Stereo/DVD: HU-850 no backlight

[MRkSTL]

Hi,

I've noticed that all the backlights on the radio panel are gone and to be honest I'm not sure if they were gone when I bought the car or that happened later.
Nevertheless, the display is ok and the climate panel below is also lit.

Is it some kind of common issue on those radios and what could be done to fix it?

Thanks

[Clan]

Originally Posted by MRkSTL

Hi,

I've noticed that all the backlights on the radio panel are gone and to be honest I'm not sure if they were gone when I bought the car or that happened later.
Nevertheless, the display is ok and the climate panel below is also lit.

Is it some kind of common issue on those radios and what could be done to fix it?

Thanks

Do the steering wheel controls work the volume etc ? if not the panel lights will not be turned on due to someone fitting a radio from another car .( Security system )

The bulbs are fixed , ie not in sockets , but can be changed if you have plenty of patience and a soldering iron and don't mind taking things apart :-) make sure you find bulbs the same with thin wire leads ie , not a higher wattage.

[MRkSTL]

yeah, they work fine. I can change the track or volume up/down.

so you reckon they all went off at the same time?

[JoeNinety]

FWIW, I changed my HU-850 for another, same model/part no., everything works, inc. steering controls, apart from the backlights (display is lit up but not the buttons)

[Clan]

Originally Posted by MRkSTL

yeah, they work fine. I can change the track or volume up/down.

so you reckon they all went off at the same time?

they usually go out one by one over a period of years ...

[Oil Burner]

Morning.

Mine went out all together one evening accompanied by an electrical fizzing sound !!!

The radio, display, buttons and nav all still work fine.

Now the mornings and evenings are lighter again it's no problem.

[Thassos]

Im guessing your missing lighting is on the radio not the climate control (lower half) of the HU850.. incidentally the climate panel uses nice and easy to replace twist fit bulbs (you dont even have to remove the housing) see pic attached.

As clan says usually bulbs fail one by one when they reach their expected lifetime (which for bulbs isnt a long number of hours..), you can remove the whole audio/climate unit as a block very easily (just remember to dis-con the battery before unplugging the climate section as i seem to recall the SRS electronics is in there somewhere and youll trigger a fault code if you unplug when the battery connected. I wonder if all the lights have gone perhaps it is an issue with some security feature that disables them? . I dont think ive ever had the radio lighting fail on mine so I wonder if they are leds rather than bulbs, anyway if you take it to bits youll find out

Anyway post your findings, and ill try and help..

• To remove the unit, prise off the panel around the gearshift then youll see the 2x tx25 screws that you need to remove (see 1st pic).
• Then pull the bottom edge of the audio block toward the gearshift, and lastly pull down to release the top edge (3rd pic) of the audio block.

Some other pics of the climate unit bulbs (white plastic round bases - use a flat screwdriver to turn and remove) attached

[JoeNinety]

This might also help:

https://www.volvoforums.org.uk/showthread.php?t=295699

I still have my old one, so might tear that apart to find the bulb locations and take some pictures.

[JoeNinety]

Two shots of the PCB

Found if I ran a current across these two bulbs, the whole lit up! But impossible to see where the power goes in and out for the bulbs - probably linked in the to light sensor ?

Tempting to solder to those two points and run power from the accessory socket?

[MRkSTL]

so all the bulbs on the pcb are soldered? any idea where that light sensor is located?