FM radio is silent or comes in poorly

Post by **FMradio** » 26 May 2022, 11:46

Hello! I have a 2006 S60 AWD 2.5T with the the HU-650 radio.
211,000 miles
There are no radio modifications to my knowledge.
USA model

I have a problem with my radio. My dad's been driving the car the last few years, and recently he gave it to me. Its FM radio used to work great, but when I got the car, it has problems. The FM radio stations are entirely silent. The stereo still displays messages from the radio station (like song name and station name), but there is no sound at all, not even static.

Also, the car can still find FM stations with automatic scanning. It knows the stations are there but won't play the sound from them.

One time when I was parked, the FM radio played sound, but only from a few stations if I recall correctly, and the stations were either very static-y or they played clearly but their signal cut in and out. By cutting in and out, I mean that the music sounds great for a second, then the sound fidelity decreases, then back to great again (not a gradual drop in quality). It's like there's a light switch that changes from "good quality" to "bad quality" and a gremlin is switching it on and off constantly.

I forget if there were any silent stations that time. I just remember that some stations barely came in and the strong stations came in strongly but the quality went up and down without the car moving.

I just tried my bluetooth FM transmitter but the FM radio won't even pick up the FM transmitter. And I just tried manual scan and none of the frequencies pick up sound, not even static. I even tried frequencies that don't exist around here but there is no sound.

The AM radio picks up all the stations (checked by comparing to handheld radio), though when I am scanning AM stations, sometimes it will think static is a radio station and stops scanning.

Does the FM radio problem have to do with an antenna amplifier like this forum post states? Are there 2 antenna amplifiers for the 2 antennas found on the back window and in the bumper? viewtopic.php?t=83631

Thank you,
Andy

iamhives · Post by **iamhives** » 26 May 2022, 21:45

I've had the same problem for a while. AM and other inputs work (e.g. homemade aux in hack thru the 10 cd changer input). Only FM has the problem. I tried changing the antenae amp with no change. I did discover that if I pressed hard on the face of the headunit that FM worked spasmodically while pressed. Also the problem seems worse when cold. It sometimes works periodically when its warm. So this led me to think its a dry/cracked solder joint somewhere in the radio (maybe the main board). I did partially disassemble the radio to look for anything obvious but saw nothing. When I have more time I may reopen it and reflow some of the solder joints. But for now I just use my aux in. I actually have a replacement radio that does something similar so I think this is pretty common as the electronics age.

Post by **jonesg** » 27 May 2022, 03:59

mine too, I never bother turn it on, it eats CD's too.
they're probably just junk.

Post by **FMradio** » 29 May 2022, 00:29

iamhives wrote: ↑26 May 2022, 21:45 I've had the same problem for a while. AM and other inputs work (e.g. homemade aux in hack thru the 10 cd changer input). Only FM has the problem. I tried changing the antenae amp with no change. I did discover that if I pressed hard on the face of the headunit that FM worked spasmodically while pressed. Also the problem seems worse when cold. It sometimes works periodically when its warm. So this led me to think its a dry/cracked solder joint somewhere in the radio (maybe the main board). I did partially disassemble the radio to look for anything obvious but saw nothing. When I have more time I may reopen it and reflow some of the solder joints. But for now I just use my aux in. I actually have a replacement radio that does something similar so I think this is pretty common as the electronics age.

Thank you for sharing your experience! It's helpful to hear the fixes you already tried. It sounds like my problem may not be in the antenna amplifier, but actually the head unit itself if it is the same problem as yours. (especially if pressing hard on the face of your head unit can fix the problem in your car)

You reminded me that on the day my FM radio was kinda working, it was hot outside! But when I've tried it again, it's been cooler or I've been in the garage where it's pretty cool. So maybe hot temperatures improve my FM radio's chances of working too.

I wonder if the antenna amplifier is not receiving power, which I've heard is supposed to be 10v. It would be great if we have a power tester so we could test the 10v power source coming from the car, whether it's being provided directly by the head unit or not.

One thing I'm curious about is how the FM radio can still receive messages from the stations or scan for stations. Also, how does our AM radio work if our antenna amp is not receiving power? I think that learning how FM and AM radio and radio data system works would give some clues as to the problem. I find it strange that everything in the head unit works except for the FM radio. Honestly, my AM reception may not be working properly because it's a bit static-y or weak sometimes. It's hard to tell as I don't listen to AM regularly so it may be normal.

I wonder if baking the head unit's circuit boards in an oven would fix it. I've heard of people baking malfunctioning computer motherboards to fix them. I honestly wouldn't bake circuit boards in an oven in case it releases something toxic, but maybe it's safe.

Just taking a stab in the dark at what the problem is here

Post by **FMradio** » 29 May 2022, 00:49

jonesg wrote: ↑27 May 2022, 03:59 mine too, I never bother turn it on, it eats CD's too.
they're probably just junk.

That's a big shame. My CD player works fine

chris11211 · Post by **chris11211** » 29 May 2022, 02:55

Same here. It's fair to say that 15 yrs is the life expectancy of a majority of the P2 Volvo parts whatever it may be. I think there's a video on someone adding a heatsink to a chip in order to stop it from overheating. Otherwise you are suppose to replace the unit with a used one, and what, have it last for 5 ish years?

Post by **erikv11** » 31 May 2022, 08:22

My S60 does this intermittently. When the volume cuts out, I can get sound back by using the steering wheel volume control. Eventually the knob starts working again (so far).

Post by **FMradio** » 31 May 2022, 13:11

erikv11 wrote: ↑31 May 2022, 08:22 My S60 does this intermittently. When the volume cuts out, I can get sound back by using the steering wheel volume control. Eventually the knob starts working again (so far).

Hmm, I think our issues may be different because my stereo works great for CD and AM. Does your CD and AM work? (At least, I think my AM works, but it doesn't pick up many stations). My FM radio is silent, no matter the volume, and my steering wheel volume controls don't cause it to work. My volume knob works except it works a bit crappily due to the switch inside being worn out, I believe. My steering wheel volume controls work well.

Post by **FMradio** » 31 May 2022, 13:16

chris11211 wrote: ↑29 May 2022, 02:55 Same here. It's fair to say that 15 yrs is the life expectancy of a majority of the P2 Volvo parts whatever it may be. I think there's a video on someone adding a heatsink to a chip in order to stop it from overheating. Otherwise you are suppose to replace the unit with a used one, and what, have it last for 5 ish years?

That's pretty lame. The parts just don't last huh. It's not a normal failure I would expect in a car. I know some cars have the LCD display die on the radio, but this is such a weird issue!

Some people replace their stock head unit with an aftermarket, which looks a bit ugly but could be a solution. I want to make sure that the antenna amplifier is getting power in my car. Another person here says they tried replacing their antenna amplifier, but it didn't fix the issue, and they have evidence the issue is in the head unit. However, perhaps my issue is not the same as theirs and it is worth trying to diagnose whatever it may be. I am not an expert or electrician, so whatever diagnosis I would try is trial and error.

I don't think my head unit is overheating because FM radio doesn't work from the moment I turn on the car, and I can't see it being possible for it to overheat in a few seconds. Do you agree? I found a diagnosis and fix about an older Volvo head unit which has a similar issue. If they used the same components/design as the old head unit, maybe this video is applicable to newer head units.

Post by **FMradio** » 31 May 2022, 13:20

Here are some people sharing their thoughts about repairing computer motherboards in an oven or with a heat gun, some are positive and some negative, and it can potentially be dangerous. I would never do this in a food oven. If I can narrow the FM radio problem to the head unit, and nothing is visually broken, I will consider using heat on its circuit boards as a repair. If the failure is within the head unit's electronics, it must take an expert to repair it, but if I'm going to junk the head unit I think it may be worth a shot to use heat as a fix.

https://community.spiceworks.com/topic/ ... therboard

Some people have interesting observations about lead-free solder in electronics failing because they aren't durable, and our head units were produced around the time lead-free solder became popular. Also Volvo is very environmentally conscious so I wonder if they used lead free solder that fails over time inside the electronics.