Super CDROM CDROM2 low volume sound

[choijimmy]

Hi,

  I recently got a super cdrom2 ( the grey color one ). I found that if I put the AV cable into the super cdrom AV port, the sound is very low at the beginning. Then after 2 mins warmup, the sound become louder with "static" sound. Then around after 5 mins, it sounds normal and volume is normal.  On the other hand, if I put the AV cable into core grafx console itself, the sound volume works great once I turn on the console ( eg, No warmup is needed )

  I suspected this is due to capacitors issue, then I replaced every single capacitor on super cdrom unit but the problem still exist... ( I even replaced some capacitors few times due to I thought my new cap went bad ). Still No luck.

  Yes, I can use AV port from coregrafx withOut any issue indeed. However, I just wonder what is the root cause for this, any idea? I read some people in different forums saying this (low volume ) is common issue for Super Cdrom and may / may Not due to Caps...

Thanks a lot!
Jimmy

[BlueBMW]

I know the volume level is a little different than the level that comes out of the core grafx but if you're still getting variable sound levels then I would recommend washing the board.  There is probably still some leaked capacitor fluid causing poor connections or shorts and are affecting your sound output.

Remove any batteries or supercapacitors from the board and run it through a dishwasher.  Turn off the heated dry cycle.  You may use a very small amount of detergent but its probably not necessary.  After washing, dab off as much of the water as you can with a towel.  Preheat an oven to 200 degrees fahrenheit.  Once pre-heated turn the oven off and place the board inside the oven and close the door.  Allow to dry for at least 3 hours, ideally overnight.  After about 24 hours have passed, reassemble the board and give it a shot.

[choijimmy]

I know the volume level is a little different than the level that comes out of the core grafx but if you're still getting variable sound levels then I would recommend washing the board.  There is probably still some leaked capacitor fluid causing poor connections or shorts and are affecting your sound output.

Remove any batteries or supercapacitors from the board and run it through a dishwasher.  Turn off the heated dry cycle.  You may use a very small amount of detergent but its probably not necessary.  After washing, dab off as much of the water as you can with a towel.  Preheat an oven to 200 degrees fahrenheit.  Once pre-heated turn the oven off and place the board inside the oven and close the door.  Allow to dry for at least 3 hours, ideally overnight.  After about 24 hours have passed, reassemble the board and give it a shot.

Thanks Byron.

I don't have dishwasher at home lol.  Instead, let me try to celan the motherboard once more by using contact cleaner / alcohol. Hope it will work.

Indeed, I don't see any obvious capacitor leak when I replaced the original capacitors. They all look good.

Thanks again!
Jimmy

[choijimmy]

cleaned the mainboard with contact cleaner + alcohol but still No luck. I think I will leave it for now since it works fine as long as I plug the AV cable into coregrafx AV port, and I already broke few traces during the re-cap and patched it by jumping the wire. Don't want to make it worst for now.

By the way, this guy got exactly issue I faced --> http://homepage3.nifty.com/moremaco/slv.htm   

If anyone have more ideas about this issue, please advise 

[schweaty]

this might help:

http://www.pcenginefx.com/forums/index.php?topic=9544.msg194417#msg194417

KC's pics arent showing up for me anymore, but if you contact him, he may still have them.

[turbokon]

cleaned the mainboard with contact cleaner + alcohol but still No luck. I think I will leave it for now since it works fine as long as I plug the AV cable into coregrafx AV port, and I already broke few traces during the re-cap and patched it by jumping the wire. Don't want to make it worst for now.

By the way, this guy got exactly issue I faced --> http://homepage3.nifty.com/moremaco/slv.htm   

If anyone have more ideas about this issue, please advise 

You will not get redbook or adpcm sound when hooked up thru the coregrafx a/v port.

[choijimmy]

cleaned the mainboard with contact cleaner + alcohol but still No luck. I think I will leave it for now since it works fine as long as I plug the AV cable into coregrafx AV port, and I already broke few traces during the re-cap and patched it by jumping the wire. Don't want to make it worst for now.

By the way, this guy got exactly issue I faced --> http://homepage3.nifty.com/moremaco/slv.htm   

If anyone have more ideas about this issue, please advise 

You will not get redbook or adpcm sound when hooked up thru the coregrafx a/v port.

 Thanks for reply. I recall Y's is using adpcm,right? How about redbook? do you mean music CD? Just tried music cd, am I am able to hear music from coregrafx av port. so redbook music means something else? how can I test it ?

Thanks again!
Jimmy

[choijimmy]

Hi Keith,

   Thanks for your help. I attached the sub-board picture

Jimmy

[choijimmy]

Hi Keith, all,

  The method Kieth suggested works like a charm! now the sound from Super CDROM AV port is crystal clear withOut any warm up. 

  I attached the picture which Keith provided. What you need to do is jump 2 wires on the both end of the  2 resistors in RED circled.  ( 1 wire per resistor )

Thanks again!
Jimmy
 

[turbokon]

I still had some sound issues after completely recapping a super cd-rom2.  Sound issues was gone after I wash the pcb.