d8b Forum

Hello all,

I may a rail cap. issue as described on this site, however, trying not to be stupid but which board/location are we talking about here? inside the cpu/psu or the control surface?

Thanks.

This is inside the d8b control surface on what is known as the brainboard. There's an excellent article in the d8b database (link at the top of this forum) under the Maintenance section describing the dreaded rail capacitor problem and related maintenance. Good luck!

Hi bitSync, thanks for this info.

The rail caps are on every board inside the console, wherever there is an IC that requires the +/- 16 volt supply. They isolate the +ve and -ve power supply rails. You have to ascertain where your problem lies.

Peter

anyhorizon wrote:The rail caps are on every board inside the console, wherever there is an IC that requires the +/- 16 volt supply. They isolate the +ve and -ve power supply rails. You have to ascertain where your problem lies.

Peter

Peter,

Not that I have this problem but I am curious. Is there any visual indicator that the capacitors have failed or must the capacitors be continuity checked for a short or tested in some other way?

The caps are polyester. They don't generally show visible signs of failure. Electrolytics mostly do since they tend to explode but not always. You need a multimeter that a) can test for capacitance or b) can test for a short or c) can show an open circuit condition. It's always been my point of view that if one goes, buy a bag of the things and replace the lot. PITA, I know but once you're in there it's best to get it over and done with and offers peace of mind. As is stated in the database, there were some duds. Cheers,

Peter

Well since I am going to be replacing these little devils, how many are in an d8b that need replacing and is it only the ones on the 16 volt rail? There are other caps of the same value inside. Should they be replaced as well?

I know there is few (understatement) but has anyone actually totalled it up?

Thanks
Bruce