Motherboard Info

[12alpha]

Hello everybody, joined this forum site today, which happens to be my birthday - so make my day !
Trying to solve a No Sound Output problem on my own PC and having checked all the obvious peripherals and settings, it looks like a motherboard failure. This Medion 6486 PC uses a Microstar 7358 motherboard with no plug-in sound board.
I have asked MEDION UK for a circuit diagram to troubleshoot but they replied that they don't have repair manuals for this PC ! (18 months old), and
suggested I disconnect power for 60 secs, then power back up to remove static from motherboard.
So, my question is: does anybody know where I can obtain a Circuit Diagram for this motherboard or offer any suggestion to solve my problem.
I am an experienced retired tech but as you know, info for the product is sometimes vital for good diagnostics. Thanks for your time.

 

[Nigel Goodwin]

They won't have service manuals because they aren't needed, you simply replace the motherboard, not try and repair it.

 

[12alpha]

Thanks, Nigel but I don't give up that easily, having spent my working life
in servicing & repair of electronic products. I feel that I should at least have
a go at troubleshooting this problem if I could get my hands on info for the motherboard. Even without a circuit diagram I would search for poor connections, dry solder joints etc. How much for a new motherboard and where to buy ?

 

[Nigel Goodwin]

Thanks, Nigel but I don't give up that easily, having spent my working life
in servicing & repair of electronic products. I feel that I should at least have
a go at troubleshooting this problem if I could get my hands on info for the motherboard.

A circuit would really be of very limited use, it's a multilayer PCB with BGA chips on it, so you can't even do measurements or tests.

Even without a circuit diagram I would search for poor connections, dry solder joints etc. How much for a new motherboard and where to buy ?

Motherboards prices vary greatly, and it's obviously an advantage if ou can get one that drops straight in your casing - but generally they are standard sizes. If you google you will find many, many sources of them, including Maplin and PCWorld.

 

[12alpha]

Thanks all, I'll let you know how I get on with this
and post any solution I find to rectify or whatever
action I take to resolve it, such as installing a sound
card if there is a slot for it - haven't looked yet.

 

[Nigel Goodwin]

Presumably you've checked the BIOS settings?, because you should be able to disable the internal sound card there.

Failing that, dropping an external card in seems a simple, cheap, and easy solution.

 

[12alpha]

Nigel, there is no seperate sound card - motherboard audio.
BIOS shows AUDIO CONTROLLER Enabled and SYS Device Manager shows no problems. Realtek Manager shows a varying, normal output to speakers but there is none.
Iv'e had to set this aside for now because I promised to burn 20 Disney movies to send to my Grandchildren before Easter. Hope the copyright watchers are not reading this.
When this prob is solved, I will report back. Thanks.

 

[Nigel Goodwin]

Nigel, there is no seperate sound card - motherboard audio.

Yes I know, that's what I meant by 'internal card'.

 

[blueroomelectronics]

As Nigel pointed out. If it's a broken built in card it's much easier just to add a sound card.

 

[DirtyLude]

99% of onboard sound is Realtek chips and you already mentioned the driver. Find the Realtek chip on your board and start poking around from there. Realtek has some datasheets online for some of their stuff, you might be able to find the sound chip datasheet that your motherboard uses. Start poking around from there, looking for blown caps, broken anything....

Seriously though, I would just do what is suggested and not even bother trying. Disable the onboard sound and spend $10 on a cheap PCI sound card.

 

[Sceadwian]

No one's asked this yet....Is it plugged in? =) Have you check for faulty audio cables or a bad amplifier? Use a set of headphones, check them on a separate CD or MP3 player first to make sure they work, then try the PC. Check your audio settings one more time. Vista should handle the audio settings itself, but XP has a much more complex audio mixer panel, it's possible software muted the Stereo Mixer, which may not show up on your mixer panel if you don't check the box in properties to make it show everything.

With the obvious out of the way, do you have a front panel audio jack on the PC? If you use headphones sometimes inserting the a jack in the front will disable the back panel jacks, try the front panel, atlernatly the front panel plug detect may have gotten stuck on somehow, you can try disconnecting it internally if it exists.
You'd be more likley to break something else more important than successfully repair the mothboard even if you could find the problem and had all the rework tools to replace it regardless of your experience.

Even if you don't have an internal slot available for a replacement sound card there are USB sound cards out there as well.

 

[be80be]

You no what most sound cards problem is you plugged in to the wrong jack. Which is easy to do now days seeing a lot of them have more jacks then the old speaker,mic,pcm, and at one time you new you had the right one it was green. Mine has two green one is for a sub woofer and you can change which one dose what. Which means I get a lot of Dad my sound don't work agin come and fix it now please .

 

[12alpha]

OK Guys, for those interested, problem Solved.
There was a dry solder joint underside of motherboard
in the audio section. Sucked and resoldered joint which
restored sound out to normal.
Like I said, with my background I had to have a go at
fixing, rather than give up and go to any expense.
Thanks a lot for all your advice