White water dead audio board help!!!

[newdos]

Hi Guys,

So bought this white water and the audio is dead. I get no 'ping' on power up but do get a power on click so speakers are working. Looking for pointers where to begin chaps ie testing points voltages etc The 5v DC light is on by the way.

All help gratefully appreciated.

Cheers Kev

 

[Sgt GrizZ]

Hi Guys,

So bought this white water and the audio is dead. I get no 'ping' on power up but do get a power on click so speakers are working. Looking for pointers where to begin chaps ie testing points voltages etc The 5v DC light is on by the way.

All help gratefully appreciated.

Cheers Kev

You done the usual resets of connectors/ribbon cable?

 

[newdos]

SURE HAVE GRIZZ - it was working perfectly then just went off total silent other than a power on click but no boot up beep even????

 

[newdos]

Ok provisional testing show no +12v on pin 4 of J503 so guessing this is the problem(I hope) - I don't have a schematic so cant trace what needs replacing, anyone point me at one???

I do have -12v on pin 3 though

Cheers Kev

 

[RudeDogg1]

Go in ipbd and you will find the manual and u will find the manual ect

 

[newdos]

I have looked in IPDB but I cant find a schematic for the pre DCS sound board. All the schematics I am finding are for the DCS soundboard which is totally different. Am I looking in the wrong place ?

Cheers Kev

 

[Paul]

According the the manual page 3-31, there's nothing on J503...



In fact, mine hasnt even a header fitted on J503!!

 

[lukewells]

Ok provisional testing show no +12v on pin 4 of J503 so guessing this is the problem(I hope) - I don't have a schematic so cant trace what needs replacing, anyone point me at one???

I do have -12v on pin 3 though

Cheers Kev

If you have -12v but not +12v then the LM7812 (12v positive regulator) at U4 has likely failed

 

[newdos]

Yeah I guessed it would be the voltage reg but I would still like a drawing so I can trace it through with a meter if anyone can help. Andy the legend must have one!!!

Paul you are correct J503 doesn't have a header on it but on pins 3 and 4 you should have -12v and +12v as this is regulated on the board itself - I have lost the +12v

Cheers Kev

 

[lukewells]

Did U4 fix it?

 

[newdos]

Did U4 fix it?

Hi Luke,

No it didn't I replaced U4 and still no +12v dc supply so I suspected that the tantalum cappy C27 had gone short circuit pulling down the 12V supply, and low and behold it had. guess the 7812 I ripped out was probably OK!!! lesson learnt check that tants first in future.

New tant fitted and all working good now thanks

cheers Kev

 

[lukewells]

Hi Luke,

No it didn't I replaced U4 and still no +12v dc supply so I suspected that the tantalum cappy C27 had gone short circuit pulling down the 12V supply, and low and behold it had. guess the 7812 I ripped out was probably OK!!! lesson learnt check that tants first in future.

Is this the same one as the one with the burnt up Tantalum?

You'll have wanted to replace the 7812 anyway, having its output shorted to ground for any period of time will have stressed if not killed the original 7812

 

[newdos]

No this is the original soundcard out of my Wh20 that wasn't working when I bought it. The burnt up one (which is still working!!) is in my FT. I will be replacing cappys and resistors soon as I can!!

cheers Kev