2009-06-08, 01:58 PM
I found the solution to a problem that's been annoying me for months. I thought I'd post it here for future reference.
The symptom is that the digital tuners don't work. I'd get nothing - no black screen. It would just refuse to leave the guide. It did this for both my QAM (HVR1600) and my DVB-S (Hauppauge 1020A) tuners. The problem could be fixed by turning off MDAPI support (I'm using MDAPI 2009) in config. I only needed MDAPI for the DVB-S tuner, but if it was enabled, the QAM tuner would fail too. Analog worked fine.
The error in logs would say :
Nothing I did would fix this problem. I'd ultimately turn off MDAPI, then a week or a month later, I'd screw up my resolve and try to solve the problem again, I'd turn on MDAPI support and surprise - it would be working!
It turned out that the fix was to remove power completely. A reboot wouldn't be enough. A normal power off wouldn't be enough. I needed to physically unplug and remove all power connections from the machine. I suspect the problem resides in one of the two tuners, but can't be sure.
My system isn't really typical - I have two separate power supplies, one of which is modified to turn on when I turn the other on with the case power switch. I also have modified the internal DVB-S card to accept external DC power to power the LNBF (I pulled this power cord as well).
I'm not sure if these mods relate to the problem, but if you have a problem that seems similar in any way - try the complete power off solution before you change too many software settings as you attempt to fix it.
The symptom is that the digital tuners don't work. I'd get nothing - no black screen. It would just refuse to leave the guide. It did this for both my QAM (HVR1600) and my DVB-S (Hauppauge 1020A) tuners. The problem could be fixed by turning off MDAPI support (I'm using MDAPI 2009) in config. I only needed MDAPI for the DVB-S tuner, but if it was enabled, the QAM tuner would fail too. Analog worked fine.
The error in logs would say :
Code:
FATAL UNHANDLED EXCEPTION:: System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.Nothing I did would fix this problem. I'd ultimately turn off MDAPI, then a week or a month later, I'd screw up my resolve and try to solve the problem again, I'd turn on MDAPI support and surprise - it would be working!
It turned out that the fix was to remove power completely. A reboot wouldn't be enough. A normal power off wouldn't be enough. I needed to physically unplug and remove all power connections from the machine. I suspect the problem resides in one of the two tuners, but can't be sure.
My system isn't really typical - I have two separate power supplies, one of which is modified to turn on when I turn the other on with the case power switch. I also have modified the internal DVB-S card to accept external DC power to power the LNBF (I pulled this power cord as well).
I'm not sure if these mods relate to the problem, but if you have a problem that seems similar in any way - try the complete power off solution before you change too many software settings as you attempt to fix it.