T4 behaving like a twin tuner

[madmax]

Hi all, it's been a while.....

My T4 has been running faultlessly until recently, when one day I found that I could no longer record two channels and watch a third (different mux), i.e. it is now behaving like a twin tuner. When attempting to change to a third mux, it freezes on the first displayed frame, and only the BACK button can unfreeze the unit by changing it back to the previous channel. Also, when a second timer kicks in, I get booted out of the channel I'm watching along with the message 'channel was changed to the recording service because a timer needs to start', as you would expect from a twin tuner. So, it seems my T4 quad tuner really does think it only has two tuners.

So, I pulled it out and checked the loop cables, visually they appear fine. I then took the cover off with the intention of un-seating and re-seating the tuner cards, only to find that they are not cards at all, and they appear to be permanently connected to the motherboard. So my last thought was that maybe the Tuner B Out to Tuner C In loop cable was faulty, so I moved them around and put this one last (i.e. Tuner C Out to Tuner D In). However, it has made no difference. I also played around with the Tuner Allocation/Priority settings (changed from default Tuner A to Auto), but that has also made no difference.

Any ideas what else I can try? Anyone else experienced something similar?

[MrQuade]

How many tuners are reported when you bring up the devices info?

Did you try setting the default tuner to C and/or D and feed them directly from the antenna?

Did sound like a fault that will require a service/repair though.

[madmax]

Devices info shows only Tuner A and Tuner B. I presume it should also show C and D?

Also, the Tuner Allocation/Priority settings does not include Tuner C or D as an option, it only has A or B. Presumably because of the above?

[prl]

Devices info shows only Tuner A and Tuner B. I presume it should also show C and D?

Yes, it should show tuners A - D.

Also, the Tuner Allocation/Priority settings does not include Tuner C or D as an option, it only has A or B. Presumably because of the above?

It can't allocate them if it doesn't think they're there. It should find them even if their antenna inputs aren't connected.

Sounds like a call to Beyonwiz support might be in order.

[MrQuade]

If a USB firmware install doesn't fix it then it's going to need to be repaired.

[madmax]

Ok, so you recommend a firmware re-install? I guess it's worth a shot.....

[MrQuade]

Ok, so you recommend a firmware re-install? I guess it's worth a shot.....

It would rule out the software pretty quickly.

Something less invasive would be to simply power off for a couple of minutes and then start up again.

I really suspect that there isn't much to be done short of a repair though.

[madmax]

Did the firmware upgrade tonight, still only two tuners.

Looks like it will have to go in for repairs.

[warkus]

Hi Madmax,

Definitely a hardware fault, have had to do several unfortunately.

There are 2 groups - of 2 power regulators under heatsinks on the board. One is a 1.2v and the other a 3.3v under each heatsink if memory serves. The heat sinks are thermal adhesive glued onto the regulators.

In the older or first series of T4 the 1.2v regulator was a TO-252 type and the 3.3v was an SOT-223 type, and being as these are not the same physical size or footprint they just used extra thermal adhesive to glue the heatsinks on level. (One is thinner than the other).

The usual fault is that one of the 3.3v regulators in one of the 2 groups has failed. Each group of regulators powers two of the tuners, so by one 3.3v regulator failing under one of the heatsinks, it has taken out two of your tuners.

In the second or newer batch of T4 units, they changed the 3.3v regulators to a TO-252 design also (slightly larger than the SOT-223) and thus the 2 regulators under each heatsink are the same size. It hasn't stopped the problem though, ive done 3.3v regulators from both batches of units newer and older.

Definitely a repair job...

Mark

[peteru]

Looks like I fell a victim to this fault too.

Any repair tips on this? I take it that any source for a LM1117-3.3 will do the trick. What about trying to hack in a TO-220 package with a real heat sink attached to the screw hole on the TO-220? Good idea or recipe for disaster?

If I'm going to repair this, I'd like it to be a permanent fix.

[Sir Lancelot]

Hi
Welcome to the club! I have had problems with my oldest T4 for a long time. The last time was in late May with problems on tuners A and B. T4 sent for repair and was sent back with a statement that nothing wrong was found with it. This cost me $99.95 to be told that.(20th June)
After the T4 was returned it seemed to work well without problem. A few weeks ago tuners A and B failed completely yet again.
I can use only tuners C and D for watching and/or recording, and then only after setting tuner preferences to C or D. Tuner Configuration shows all tuners present.
As yet I don't know if I can record 2 programs at the same time (on different muxes).

I don't know what to do about this problem at this time. I honestly do not believe the problem I first reported was fixed.

I have sent a copy of this to Beyonwiz Support Desk

I will keep the forum up to date with any solutions offered.

Regards
Lance

[peteru]

Can you spot where things may have gone wrong?

Voltage regulators for tuners C and D

This is one of the first T4's ever made. It's been running continuously (24x7) with the fan off, but in open space with good airflow, since 2014.

The voltage regulators ICs are supposed to have a thermal shutdown that turns them off at around 150C. I'm not so sure that in this case it worked, since the thermal damage was so bad that the solder mask ended up blistered and peeled off when cleaning up with iso-propyl alcohol.

As bad as it looks, only U47 failed. It was generating ~2.5V instead of 3.3V. The 1.2V regulator is still good. I decided against using a TO-220 part as a replacement because the heat sink tab is the output of the regulator and having a heat sink attached to the tuner 3.3V rail and protruding into the case seems like asking for trouble. Instead I used a TO-252 part to match the physical size of the 1.2V LDO regulator. It has slightly better thermal characteristics than the SOT-223 part, but luckily it just squeezes in to the footprint of the existing part. I wonder why the designer decided to go into the expense of using (fairly ineffective) heat sinks glued to the top of the parts. There's plenty of space on the board for proper copper plane heat dissipation with TO-252 or even better, with TO-220, part.

Anyway, for anyone contemplating self-repair, you'll need a hot air SMD rework station with the correct size nozzle. I would discourage you from trying with a soldering iron - you are likely to cause even more damage.

[Altimes]

I had cause to lift the cover on my T4 recently and noticed some obvious hot spots on the PC board. Thermal paste looks OK, but the PC board looks a little stressed.

From those who have had lots of experience of looking at these, Mark , are these at the level of likely to need a little holiday in WA ?

[prl]

Do you mean the area around U16? That certainly looks unhappy.

[Altimes]

I had noticed that hot spot, but had not noticed that it had an IC in it. I was thinking about the area around U44 and U45

[MrQuade]

They all look pretty suss to me.

[prl]

I had noticed that hot spot, but had not noticed that it had an IC in it. I was thinking about the area around U44 and U45

Yes, they look pretty dodgy too.

[Paul_oz53]

They all look pretty suss to me.

+1 - I'm scared to open the T4 now - no telling what I might find!

[peteru]

Do you mean the area around U16? That certainly looks unhappy.

The stains around the U16 footprint must be some kind of external contamination. U16 and friends are not populated, so there is no way that the mess came from that area of the board. The U3 area looks fine.

U44-U47 look like they are contaminated with the same black crud that shows in my picture.

I'd say take a temperature reading on top of the heat sink, just where it contacts each regulator case. If the hot spots run at 90C or lower, I would not worry too much. The parts are designed to operate with a junction temperature of up to 125C and thermal shutdown should kick in around 150C. The thermal resistance of the SOT-223 part is 15C/W (TO-252 is better at 10C/W) and the 3.3V regulator should not dissipate more than 2W. So, 30C under max operating temp puts you at 95C. They probably should have used buck converters instead of LDO linear regulators, or at least have one regulator per tuner, to spread out the load.

[stevebow]

Reading the above, I also took a look in my T4 (which is usually in deep standby when not in use). It has the same board revision/5114 datestamp and the same thermal stress signs around the regulator heatsinks that Altimes has in his photo, although I suspect in Altimes' case the very dark grunges are possibly ingress of liquid of some sort through the vents.

It's not very apparent in my photo, but the brown pcb discolouration in the area around the heatsinks is much more obvious to the naked eye. I think I'll look into replacing those heatsinks with something a little better...

It is quite dusty where I live and every month or two I pop the cover and clean the dust out of the unit, especially the various heatsinks on the mobo and psu. Without the regular cleaning and deep standby, it's seems that I may have had to replace one or both regulators already!

BTW, does anyone know what the white connector J10 to the right is for?

[peteru]

BTW, does anyone know what the white connector J10 to the right is for?

Special Broadcom hardware debug interface. Used to debrick the motherboard in case you kill the bootloader in the flash. It's not JTAG, in case someone is tempted ...

It looks like you also have a mix of SOT-223 and TO-252 parts with a single heat sink on both of them. That is a dumb idea, since the heat sink does not make a good connection with the part that needs it the most. If you are going to play around with replacement heat sinks, install four of them, one for each regulator.

[stevebow]

It looks like you also have a mix of SOT-223 and TO-252 parts with a single heat sink on both of them. That is a dumb idea, since the heat sink does not make a good connection with the part that needs it the most. If you are going to play around with replacement heat sinks, install four of them, one for each regulator.

Good idea, thanks.

I've had a preliminary go at removing one of the heatsinks, but the adhesive is quite tough. As you've already done this, do you have any tips with your experience? I don't want to damage anything if I can help it.

[peteru]

Mine was so baked that it just crumbled with a slight amount of twisting motion.

If you need to use some force, I suggest a very thin jewellers screwdriver or a razor blade. Slowly and gently work your way around the perimeter a few times to separate the sink from the IC packaging. Be very careful to not pull the IC from the board or exert much force on the pins of the IC. If you start lifting tracks off the PCB, you are in a world of trouble.

[dogfox]

Hi Guys,

looks like I have fallen victim to this fault. Does anyone know what my optio ns are?

I have a desoldering station (vacuum, not hot air rework).. would that help or...

Is someone on this board willing to repair ths unit for me (chargable, of course) or is it a -send to Beyonwiz sevice- deal?
Im in Vic, about 30 mins from Geelong if that helps.

Should I be looking at purchasing a U4 or something else?

Any feedback welcome
Thanks

[IanSav]

Hi Dogfox,

Contact Mark (Warkus on this forum). He can and will sort this out for you.

Regards,
Ian.

[dogfox]

Just a bit more info if it helps

about a month ago tuner A went funny - like the antenna was not oriented properly.
I switched the pvr so tuner C was the primary (but didnt really check if tuner A got better). Tuner C was perfect.
Then the night before last, I thought I put the pvr in deep standby but the next morning I noticed the pvr was still running ( I could hear the fan running).

There was some message on the front screen, but I didnt read it... I just pressed OK and the OK again on the remote and the PVR went off.. I never turned the tv on during that episode. Then, that night, I turned on the tv and pvr. The pvr showed the beyonwiz logo but never showed any percentages.. It went from 50% to 99% on the front screen and now will not show any free to air broadcast at all.. No audio either. I can play recordings, however. Devices info shows only two tuners A and B.

I have removed the heatsinks and noticed black stuff around both 3.3 regs. The left 3.3 reg (for tuners C and D) is missing some the green board coating (i can see copper) and there is some blue/green corrosion around the big 'pin' at the back

[Paul_oz53]

In this post and following are stevebow's instructions for replacing the regulators if you want to do it yourself. However, Warkus is a great alternative.

I ordered the parts for mine but when I opened it up there's no sign of damage so I put it aside for now. It took nearly two weeks for the package to arrive because of a slack courier but cost less than $20 all up.

Looking at smd repair vids on YouTube, a key factor in successful repairs is to use plenty of smd flux. Some use hot air but others use temp controlled irons.

If in doubt, send it to Warkus.

[peteru]

You are unlikely to be able to get the regulators off the copper plane without using a SMD hot air rework station, at least not without causing damage. I have a desoldering station with an electric vacuum pump and it's not the right tool for this job. Neither is a soldering iron with braid/wick. A gallium alloy is pretty much the only other option.

If you don't have the right equipment and skills, find someone who has. It does not need to be Warkus or Beyonwiz. Any decent electronics repairer will be able to do the job if you give them the information in this thread.

[Dawizz]

Hi,

I have been having these issues that are described in this tread for the past 3-4 months.
I have opened my T4 up and had a look at the two 3.3v regulators and they look good, I even done a voltage test and I get 3.2v - 3.3v out of them.

I have upgraded the heatsinks to RS 750-0908 - 20 x 20 x 19.1mm Heatsink with Adhesive Foil, that was in this thread.https://beyonwiz.com.au/forum/viewtopic ... 53&t=12841

I had a WD 2Tb WD20PURZ 3.5' SATA HDD and thought that this may be an issue as well, so I installed a Seagate Barracuda 2TB (2000GB) 2.5″ SATA HARD DRIVE. This did not make any difference, I even ramped up the fan to full speed when running ... same...

What happens is that I would be flicking through the channels and then it would freeze up (the picture would be still), channels A B show red . I have tried to change the channels in the tuner setting to C & D but this has not helped and I tried auto as well, no luck. .
The only thing to do is (Windows ) switch it off and back on again.

There is nothing on top of the BW and there is good air ventilation.


I am at a loss as I am beginning to hate this bloody thing as sometime it wont even record the shows I want to watch


Can anyone please suggest something????

Thanks,

[peteru]

Can anyone please suggest something????

Warkus.

[dogfox]

When I had issues with my T4, I contacted Warkus privately. He was very knowledgable and accomodating. He explained what had occurred and what needed to be done. I sent him the pvr and he took it from there. He kept me updated throughout the repair and sent it back very quickly.

I got it back last night and after fighting with the mass of bubble wrap, it is back in its proper place and working perfectly.

I would recommend him to anyone. What class!

Thanks again Warkus