NextPVR Forums

After returning to the TV guide from watching live TV I am unable to watch another channel. I get the error 'unable to communicate with recording device' followed by 'device not present' on subsequent attempts to watch a channel.
The only way I have found to fix this is to manually stop and then re-start the NPVR Service.

Using a USB AF9015 DVB-T Tuner in the UK
Fresh install of Win7Ultimate
NPVR Version 1.5.33

Thanks for any help anyone might be able to provide.

Stuart.

P.S. I can't confirm this right now, but I think this problem is NOT present in WinXP. I have GBPVR setup on my XP disk along with a test install of NPVR, but NPVR is too sluggish on XP, so I installed Win7. If I get a chance I'll boot up XP again and see if I can repeat the problem in XP.

Logs attached.

I did a search and found a few similar issues, but none identical to mine, hence the new thread.

Similar problems:
http://forums.gbpvr.com//showthread.php?...iled+start

Since your error message indicates a possible memory corruption, I suggest doing a full run of memtest 86+ (http://www.memtest.org/) just to be sure. Your problem is not something anyone else has reported to my knowledge.

Assuming the memory test comes back ok, check that you have the latest drivers for your device.

Hi I can confirm that AF9015 tuners give problems I use them with version 9-6-031 drivers from ITE who make the 9015 chip used in the device which is sold by many manufacturers
The symptoms are as follows .. NPVR detects the dual tuner as AF9015 and AF9015#2 in the devices section ... most people will then turn the fist tuner which NPVR will do fine ... then they copy the config to the second tuner as prompted so saving the scan on the second tuner ...
But if you try to scan the second tuner AF9015 #1 instead of copying the settings from the first tuner the tuning hangs and does not pogress...
In use with NPVR if you load the SHOW STATUS option from the tray then you can run NPVR not in full screen mode and select shows to record and watch the tuners select ... you will see the first tuner select on the dual USB device .. but as soon as you decide to watch a show or use the second tuner to record a show you normally get " unable to connect to the recording service " as the first message ... then if you try again you get " device unable to start"
I have tried NPVR under XP Vista and Win7 using the AF9015 ... also using different versions of the driver for the device .... the dual tuner on a single usb .... not selecting the second tuner only happens in NPVR the software provided by the manufacturer works ok on both tuners ...

NPVR detects the dual tuners but has a problem moving from the first device to the second etc
NOW the odd fix .....
if you read my prior post on another thread I came accross a strange fix which now allows me to use 4 USB dual tuner try it and see if it works for you

Download DVBLink TVSource 1.0.2 from http://www.dvblogic.com/legacy.php then run DVBLinkServer.msi this installs 4 "fake" tv sources (tuners) we arent going to use em but hey

then shutdown the computer , turn off the power then power it all back up load NPVR in a window not full screen ,, load the show status window from the NPVR Tray ,, tell NPVR to record programs which are showing now and watch the tuners select then select another channel to record prefer one that selects another tuner ie not broadcast on the same multiplex .....

see if NPVR selects all the tuners one after another untill you can prove that the tuners select properly .. and watch the recording to prove the correct operation..

In my case NPVR would only select the first USB tuner in a dual device and would report unable to connect to the recording service the first time you need the second tuner then would report unable to start the device the second time you need a second tuner ... installing the DVBLink dummy tuners fixed the problem ,, WITHOUT changing the NPVR settings .... you can go to settings and devices to see the 4 dummy tuners the DVBLink software installs ... I just set them to disabled and dont use them
this strikes me a a wierd fix .. but it works for me and I can repeat this as I tried the install and fix many times before opening my big mouth ,,,, try it ... it it doesnt work for you on you dual USB tuner problem let me know as I would hate to give anybody a wrong tip ... please come back with comments ,,, I dont know why it works for me I just know it does and 6 clean intalls on different hardware platforms back it up using my AF9015 based dual USB tuners

Please let me know if this strange fix works for you ?

I would like to reference

http://forums.gbpvr.com//showthread.php?...ners/page4

sub says "I think the problem was something really simple all along. The app was expecting that when it asked windows for the list of BDA tuners installed, that it'd return them with same named ones next to each other n the list. Your drivers were the first we'd come across that didnt do this, and alternated between DVB-C and DVB-T. So a simple case of sorting the list returned by Windows fixed all your problems (one single line of code). "

it may be that when I load the DBLINK software it changes the sequence that windows reports the BDA Drivers to NPVR as it adds to dummy drivers ???

it may be that some dual USB tuners have a problem ?

Thanks johnsonx42, I ran memtest when the system was new, and got no errors, but after reading your post I ran it again and got errors so I re-ran it with each of the two modules in on their own and got no errors! very frustrating. Maybe it was just a poorly seated module??? Anyway, I'll leave memtest running overnight and then boot back into Win7 to see if the tuner problem is still there.

I didn't think it was relevant to my first post, but I am trying to run NPVR from a ramdisk, so that may have something to do with my memory problems, or might not... I'll move it to a hard disk to see if that solves it and report back.

fibreoptix, Thanks for your huge reply. I only have a single Tuner so I'm not 100% sure we share the same problem, but if the overnight memtest goes ok i might give the solution you posted a try to see if it cures my problem too.

Thanks for the help guys,

Stuart

It wouldn't be the first time someone fixed memory problems by simply reseating the modules, and it certainly won't be the last. However I've seen cases where two modules will each run fine alone, but won't work together.

johnsonx42 Wrote:It wouldn't be the first time someone fixed memory problems by simply reseating the modules, and it certainly won't be the last. However I've seen cases where two modules will each run fine alone, but won't work together.

I agree, but both modules have just passed 7 hrs of memtest, so hopefully it was just a re-reseating issue this time. I'll post more on my success/failure with the tuner after work.

Stuart.

7 hours of memtest ought to do it.

I tried running it all from the HD instead of RAM Disk, but the same problem occured, so i took a closer look at the logs and options in the settings menu and noticed this at the end of my NRecord.log:

So I figured it could be something to do with the graph (whatever that is) and lucky for me there is an option to keep graphs constructed in the settings, so i ticked it and now I can watch, stop, re watch, standby, etc and the tuner will come alive each time I ask it to show a TV channel.

The only problem I have found is it appears to take slightly longer to go from the guide to Live TV now, but switching between TV channels is almost instant.

I guess the tuner drivers or NPVR were having trouble re-constructing the graph after the tuner was shut down.

Does anyone know exactly what the graphs are, and if keeping them constructed is a good/bad idea?

Stuart

I know what a graph is, but can't think of exactly how to explain it... let's see... to record or playback media in windows, you construct a logical chain where the data comes from an input device (say, a media file, or a capture device), and flows through various filters that process the data (media splitter, video decoders, audio decoders, in the case of playback, multiplexors and encoders in the case of recording), and then finally to an output device (video renderer and audio renderer in the case of playback, or a file on the hard disk in the case of recording); that contruction is called a "graph".

If keeping the graph constucted solves your problem, then it's a good idea. I think sub added the option to work around a driver issue on SiliconDust HD-Homerun tuners. I think the primary negative consequence of keeping the graph built is that no other application can access the tuner while NPVR is running, which is usually not an issue.

I'm curious, do you still get the memory corruption error in your log now when it fails?