SSlmixed.com Forum

Tech discussion => 4K,6K,8K Series => Topic started by: Dave Dicson on July 15, 2026, 06:59:26 PM

Title: SSL 4K VCA to Monitors is not working.
Post by: Dave Dicson on July 15, 2026, 06:59:26 PM

We have 2 SSL 4K G Series large format consoles, that about every 5 - 10 months The VCA to Monitors button just stays on and does nothing on both SSL's when pushed. What is happening is that TR7 (BC212L) transistor on the 21 card is shorting. Anybody have any idea why?. I just replace them until next time, when it happens again. Maybe transistor is not heavy enough for the logic load on these big consoles? Are small SSL 4K console has never had this problem. Thks for your info.

Title: Re: SSL 4K VCA to Monitors is not working.
Post by: walrus on July 16, 2026, 04:30:39 PM

Maybe try replacing it with a ZTX553 which has a 1A current rating.
Different pinout, but I'm sure it can be fitted.
https://4donline.ihs.com/images/VipMasterIC/IC/DIOD/DIODS13225/DIODS13225-1.pdf?hkey=6D3A4C79FDBF58556ACFDE234799DDF0

Title: Re: SSL 4K VCA to Monitors is not working.
Post by: Dave Dicson on July 20, 2026, 04:04:45 PM

Thks Walrus. I'll look into it. So far everything is working, but I don't know for how long.