t4 crashing (suspect overheating)

[drharry2442]

My T4 crashes quite often when in normal use, no particular pattern of usage that I can detect.

When I look at the information panel there are a lot of version numbers for various things but I hope this is the one you need to know,
kernel 3.14.2
version 17.5
enigma17.5-819.

I do keep the software up to date when I am told there is a new version and this problem has been happening for the last few versions ( I have just been lazy about reporting it).

There are no errors when it crashes and it does attempt to reboot itself. Sometimes it comes up OK and runs for a while before crashing again but mostly it just crashes again immediately. My solution has been to switch it off for 30 minutes and then it seems to come up fine.
I have made sure the inside is clean and free of dust.

I suspect it is due to overheating because I have ended up taking the lid off and keeping it off when using it and it has never happened when I do this.
The machine does run incredibly hot and has done since I bought it.

I have tried changing the fan settings to max in both normal and standby mode with no success.

Anyone got any ideas or am I doomed to using it with the lid off permanently ?

is there a more powerful fan I could install ?

[Grumpy_Geoff]

If the GUI crashed then there usually is a crash log written. Take a look using File Commander (MENU>>Sources / Files). Navigate to Internal Flash, then 'home', then 'root', then 'logs' (/home/root/logs/).
If a crash log is present, copy the log to a USB drive -
Have the log directory open in one File Commander pane and the USB drive open in the other pane (you can use PREV/NEXT to switch panes).
Then select a crash log from the "log" pane and copy it to the "USB" pane using YELLOW/Copy.
Pressing MEDIA will allow multiple files to be selected (OK to toggle file selection)
Exit back to live TV.

To eject/unmount the USB, in 20180417 from live TV press BLUE and choose 'SimpleUmount', from 20190207 firmware then SimpleUmount is located towards the bottom of the plugins column of the main menu).

[prl]

I have ended up taking the lid off and keeping it off when using it and it has never happened when I do this.

Be aware that when you do that, exposed parts of the power supply are at more than 300V.

If you look at the two black U-shaped heat sinks just in front of the tuners in the T4, is the cement that holds the heat sinks onto the components discoloured brown? If it is, you need to get that part of the T4 repaired, even if it's not the cause of your current problems. But it could also be an indicator that the breakdown of the cement is the indirect cause of the problems.

[prl]

When I look at the information panel there are a lot of version numbers for various things but I hope this is the one you need to know,
kernel 3.14.2
version 17.5
enigma17.5-819.

In MENU>Information>About, the most relevant information is Revision, which is a version datestamp.

But I suspect that the issue isn't with the firmware, unless it has been corrupted somehow (and that probably wouldn't show in the About information).

[Paul_oz53]

Not at home so can't check but when I ran the infrared thermometer over the T4 I got high readings on the two heatsinks on the LHS in front of the tuners. The regulators beneath are known to be a source of failure, as prl knows only too well.

Upping the case fan is unlikely to make a big change because it is too far away from the heatsinks.

I have an old 80mm fan on the outside of the case over the sinks which I am powering from a plugpack as an experiment but it is a crude setup. It's too noisy to be practical but a low noise fan and a lower voltage might work.

Mine is in the open so access is easy. Just about fan pointed at that region should lower the operating temperature. Might be worth a try to see if it restores normal operation with the case on. If so, laptop cooling pads might be an option to investigate, especially if they are variable speed.

[prl]

A T4 in a well-ventilated situation shouldn't run all that hot. I have a T4 in my test stack that has a U4 sitting on top of it (not a recommendation, by the way ). It's been running now for several hours, and the top of its case is comfortably warm above the power supply and above the tuners. The tuner sockets are slightly warm. OK, it's not a hot day, either, 25deg inside, but it really shouldn't be running particularly hot.

[prl]

Not at home so can't check but when I ran the infrared thermometer over the T4 I got high readings on the two heatsinks on the LHS in front of the tuners. The regulators beneath are known to be a source of failure, as prl knows only too well.

Yes, but that's often an indirect process: hot components -> breakdown of thermal cement holding the heat sink -> release of corrosive compounds onto the PC board -> erosion of the solder resist and copper tracks on the PC board -> various different direct failure modes. Actual thermal failure of the regulators may happen, too, but I'm not sure how frequently.

[Paul_oz53]

Yes, but that's often an indirect process: hot components -> breakdown of thermal cement holding the heat sink -> release of corrosive compounds onto the PC board -> erosion of the solder resist and copper tracks on the PC board -> various different direct failure modes. Actual thermal failure of the regulators may happen, too, but I'm not sure how frequently.

Yes, I agree its important to address the breakdown of the thermal cement. If that happens then the need for repair seems inevitable. In my own case, the T4 is not showing any sign of breakdown so I am hoping extra cooling will prevent deterioration.

If the cement hasn't failed yet then the original problem is apparently overheating. If so, a fan may help. Of course, it may be hidden damage that's at play here and no amount of cooling may prevent eventual failure.

[drharry2442]

thanks for all the replies.
my T4 is running in my bedroom on top of a chest of drawers with no other equipment near it so any heat being generated is from it and nothing else. it is well ventilated and the room is not hot either. the thing I would stress is that I have never had it crash when the lid is off (which is all the time now). Most of the heat seems to be coming from the tuners but there is quite a bit from the small board on the right hand side. I have an ssd in it which does not seem to be generating any heat.

I guess I will have to investigate the possibility of doing something with the heat sinks to cool it down.

thanks again to all for taking the trouble to reply.

[drharry2442]

sorry, forgot to mention in my last post. I have checked but there are no crash logs.

[prl]

Most of the heat seems to be coming from the tuners but there is quite a bit from the small board on the right hand side. I have an ssd in it which does not seem to be generating any heat.

The board on the right is the main power supply.