Beosound 5 repair

[Madskp]

Starting to look at a non working BS5/BM5 I have.

When applying power the LED on the Back of the BM5 is green and the LED on the BS5 screen is red.

The 4 red status LED’s with voltages on the Masterlink Board are all light up.

The fan is spinning.

However nothing is happening if I press the power switch on the Back of the BM5 or the standby button on the BS5 screen.

So far I have tested the following:

• The harddrive in another computer. I am able to acces the partitions on the harddrive, so that should be ok.
• Connecting and external screen to the BM5 unit. Not working
• Reset the C-mos on the motherboard. Not working
• Took out the motherboard and tested it separatly with another ATX power supply. Not working.

So I guees for one thing the motherboard is dead.

So to get on I have a couple of questions:

• Can I somehow test the BS5 Screen separatly to see if that is working? I have tried to hook the DVI connector up to another computer while getting power from the BM5 unit, but that didnt seem to work.
• I have found some posts in the older forum mentioning bad caps on the motherboard being one reason for not working. Can anyone tell me which caps it could be? There is one next to the ATX connector with a very slight bulge, but all the others has no visible problems.

Thanks i advance.

[kirin]

Hello,

you said, reset the CMOS, did you check whether the battery has the correct 3V voltage?

I had one where I thought as well the mainboard might be dead but it was just an old battery

In case of mainboard, it might be interesting whether similar VIA EPIA mainboards could be used as well. meanwhile they got more and more expensive

Best regards

[Madskp]

Hello and thanks for the input.
I have measured the battery voltage to 3V, but I could try to put in a new one tomorrow just to rule that out.

Could be interesting with another motherboard. The only one of the same type I can find cost more than another BM5/BS5

[XavierItzmann]

Woah,

Just a second there.

There is a battery inside the BM5? My BM5 is over a decade old.  If there is a battery inside, that’s an acid leak waiting to happen (may have started, for all I know) and BM5 destruction should be imminent.

So, is this a maintenance item, what is the battery model?

Any other maintenance items?

Thanks!

 

[Madskp]

Dont worry, its just a CR2032 coincell battery on the PCmotherboard to hold the clock. I have never seen leaks on these even on very old computers.

[Madskp]

kirin wrote:

Hello, you said, reset the CMOS, did you check whether the battery has the correct 3V voltage? I had one where I thought as well the mainboard might be dead but it was just an old battery

I replaced the battery today, but still no luck.

I also meassured that all voltages on the ATX connecter is within specification, and they are.

Next I replaced 2 1000uf caps next to the ATX connector as one of the looked bulgy. Still no sign of life.

 

[Madskp]

Continuing I noticed that the CPU cooler gets very hot. I have measure the CPU Vcore voltage which is around 1.0V. This doesn’t sound critical to me, but I don’t know what the correct voltage should be.

Also measure random voltages around the motherboard, and nothing looks suspicious.

Also did some checking for short circiuted caps, but that is not the case either.

 

I am a little interested to see if I can make the BS5 screen show some life. Does anyone know if it should be possible to make i show the picture from an other computer, provided power is supplied to the BS5 screen?

Or should it have some signal via the USB cable?

[Madskp]

I managed to get hold of another motherboard for the BM5, the 1,5Ghz version for aaround 40€ including shipment and another mini itx motherboard.

I have installed the replacement motherboard, updated the BIOS and done a restore.

Although it took some boot loops and manuel restarts it now seems like it is running like it should.

Next issue the sticky black coating, and a broken glass on the BS5 head unit.

[B3OHACK3R]

Madskp wrote:

Does anyone know if it should be possible to make i show the picture from an other computer, provided power is supplied to the BS5 screen?

Yes, works.

Madskp wrote:

Or should it have some signal via the USB cable?

USB is a normal HID device. You can control the red LED and also read out any input values from the controls easily. Unrelated to the screen itself. Played with that many years ago.

[Tignum]

Madskp wrote:

Next issue the sticky black coating []

Hi Madskp, I managed to rub off the sticky coating with methylated spirit (the blue smelly stuff), and found a gloss black paint underneath. My original idea was to have the housing sandblasted and powdercoated, but I abandoned that and am happy enough with the original black (undercoating) paint. Saves quite a bit of (dis)assembly. Maybe worth a try? Regards, Johan

[Madskp]

Tignum wrote:

Madskp wrote:

Next issue the sticky black coating []

Hi Madskp, I managed to rub off the sticky coating with methylated spirit (the blue smelly stuff), and found a gloss black paint underneath. My original idea was to have the housing sandblasted and powdercoated, but I abandoned that and am happy enough with the original black (undercoating) paint. Saves quite a bit of (dis)assembly. Maybe worth a try? Regards, Johan

I have tried that now and also IPA (not the beer) and both seems to do the job. It requires a bit of rubbing but eventually the sticky stuff will come of.

The surfaces tædo have some scratches to the metal in a few spots where the rubber had melted back over the scracth so might need a repaint at some point in the future. But it is not tha visible at is on the backside and now it is at least not sticky anymore 🙂

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