V70 Stereo/DVD: HU-850 Findings

[marcb]

Originally Posted by Jonny5isalive

The replacement unit arrived today and it has Mitsubishi Electric on the stickers, I'm assuming they all are made by them, but don't know for sure. Expected more from a top electrical company. Good news is that the radio works superbly. I've never heard such an awesome sounding factory fitted system. Bad news is that the CD player just shows ERROR on the display and the unit has things rattling around in it... Grrr! Contacted salvage yard.

If I were you I'd get some money back and keep the unit. As Symes says you can try your old CD unit but you can also put in a Grom to play from a USB stick or phone. The CD on ours is bust but with the Grom I don't miss the CD now - it really is old technology.

M.

[TLPower]

+1 for the Grom, my HU 850 ate it's multichanger, 2 teeth missing from 1 gear at the base of the stacking part.

The grom solves the issue with no loss of sound quality.

Or you could as you already mentioned swap over the multichanger from your old unit and wait for the inevitable.

[Jonny5isalive]

Well I've cracked it! It took me a couple of hours but was pretty straightforward, even with my sausage fingers. Stripped the innards out of the head unit to find 1 smashed cd and another intact cd in the mechanism, with bits of the actual mechanism rattling around in there for good measure. Long story short, transplanted my working mechanism into new housing and now have a working radio, cd player and parking sensors! I shouldn't reverse into anything now. Well, that's in theory...

Happy bunny.

[TLPower]

Top job, well done.

Enjoy.

[jikan]

Originally Posted by Smashed Monkey

Well, I have been over all the components except for the aluminium caps on the main board. I had none of the correct value in my spares stock. I have improved the situation quite a bit, where the radio or CD plays for quite a time after switching on, but sadly, after about 10 minutes, a crack and then silence. So still not resolved. I suspect the capacitors, but probably a semi-conductor going down, and the worst of it is that now in my 50s, I can't see the sodding little things - even with my glasses on and a magnifier!

I have decided that I am on a fool's errand with this. I don't think it is work the bother as I really want to use the amplifier to allow me to play the music playlist on my phone. I don't have the time needed to work on with this and my wife is fed up with the piles of screws and bits of stereo littering the dining table.

I would love to know what the fault was, but I don't suppose anyone will be able - or more accurately - prepared to tell me as it would potentially kill off a nice little income stream from the repair of these rather disappointingly unreliable units.

I'm going to junk this unit and buy myself a more up-to-date unit which will support Bluetooth and USB playback as well as support my Samsung Ativ-S Windows 8 Phone. (I know, now I am really asking...)

It would be good to know if there is a head unit (double or single DIN) that would work well in the Volvo. Also a decent fascia adaptor so that I don't have to butcher the original console front?

Hi, i have had the same problem and solution was to resolder IC under metal shield

http://forums.swedespeed.com/showthr.../165887?page=1

See reply #9

[ma70]

I might have to give this a shot, if I can find my soldering kit. Nothing to lose IMO, if I fail/break it even more I have no stereo as when I bought the car but if I manage to successfully reflow the IC's then at least we can see how the HU850 sounds for a while. I understand it may not be a permanent fix but hopefully will buy some time to judge whether we want to replace it with an OE unit or go aftermarket.

I'll post back if it works out.

[ma70]

Seems reflowing the 3 surface mount chips between the tuner can and another shielded part of the board, and 2 resistors on the underside in the same area, has improved the problem no end. (my main board looks like the one in the first post on this thread, the one on swedespeed looks different?)

I believe that once I've got set up with a smaller iron more suited to SMD reworking I should be able to fix the issue fully, but for now I'm happy with the results. I would say this "no sound/intermittent popping" fault is caused by failed solder joints in this area of the board. Judging by the telltale sh!t stains in the vicinity I'd lay money that it's caused by thermal stresses over time.

Long term, I think the only permanent cure would be some kind of ventilation or heatsinking in this area. Otherwise, it looks like occasionally reflowing cracked solder joints is a "routine maintenance" task to keep an HU850 working.