Help please, if anyone can.

Symptoms, will not boot. After power application standby light is red, drive spins and seeks and then nothing more display being blank.

Only recently found this forum and it's been good so far for me. My T825 has failed but at least to date i have been able to copy off the recorded videos. So I posted the results on the forum threads where found the advice and what I did.

So having the pix safe I now hope somebody can help to see if the pvr can be repaired.

I took out the drive and tested it (Seagate Tools) prior to copying off the videos so I am confident the drive is fine.

Tested the external PSU 12v off load and 11.89 volts - measured at the motherboard connector - when on load (board and hard drive) so that seems fine too.

Guess the problem is the board components or some other quirk. Board id 16MB835N-4 -which I thought was a T835?? but it has the single scart socket and no processor heatsink.

Can anyone help with further diagnosis or somewhere that can do an economic repair?

Have you tried a different power supply? Simply measuring the voltage may not tell you if there is anything wrong. So first thing would be to try another PSU. Doesn't have to be exactly the same type, just one with the same voltage output and equal or greater current capacity.

The other thing to look out for is dodgy capacitors. Seems to be a common theme with some of the cheaper kit that they use poor quality capacitors which fail over time. Look for bulges in the top of the capacitors (most electrolytic types should be flat or very slightly concave) or leakage around the base. If you know which end of a soldering iron is which then it might be possible to swap out any iffy caps and if you are lucky revive the unit.

If you have an external PSU, then you indeed have a T835, not a T825 (which has an internal PSU board and fixed mains lead). Any particular reason why you thought it was a T825?

I agree with you that it is unlikely to be a HDD problem as it worked when connected to a PC, although that isn't a conclusive test. However, if the front panel stays completely blank when plugging the PSU on, then this unfortunately does indicate a problem with the main board. Assuming the PSU is not at fault, and has already been suggested you should try an alternative (anything with 12VDC output and 1A rating or higher should do for a quick test).

When you plug the PSU in, what is the exact colour sequence of the power light? Normally it will flash red/green a few times as soon as you plug it in, before it boots. If this is the case then you may be ok, otherwise if the power light stays solid red then the problem is probably terminal. I have had a few boards which refuse to boot with a solid red LED, and have never figured out a way to fix them - of the few normal capacitors (although most are SMD), all looked fine and even replacing them did not help. If you are lucky enough to have a power LED that does flash still, this indicates the bootloader is alive - in which case, reflashing the software can often revive the board.

Reflashing the software involves making or buying a SCART->RS232 adaptor and connecting to the serial port in a old PC ideally (or failing that, some USB->RS232 adaptors do work). The box will display some text output on the serial link to again verify that the bootloader is ok, and whether it is able to load the software.

Thanks both for the quick responses.


No not yet as I believed that the correctly measured 12v dc output (no AC ripple to speak of) when connected (and with the unit therefore drawing current) will be what is required so I'm not sure what you mean, Chris. However I'll find another PSU and connect to prove that the one I have is the cause or not of the failure.(the only ones to hand have different sized connectors! Just my luck)

All electrolytic capacitors look fine visually, Chris (but I realise that is no guarantee they are OK but the opposite would be true!) - I could take each one out and test it or scope it. I'll leave the latter just for now.


err oops , my mistake I assumed that the 250BG version was T825 but I note it is a T835 according to the label! - if all else fails read the ........

Understand what you say about HDD, Fataura, although Seagate Tools is good for a basic 'non file content' test. Does the unit require a boot sector/program on HDD? From what you say it does look more like a board issue - the sequence is: off, plug in power, red led....red led.....red led so never seems to get as far as bootloader.

Looks like, if Chris's suggestions do not lead to revival, it's a dead duck then ( I will tackle all pcb mounted components except smd ones and there is not much info, as far as I know, about the board, it will be difficult to progress.)

Will report back after I've tried the suggestions.

Are there any repairers of these units or spare boards available? - perhaps jumping the gun there but I do not get a confident feeling about fixing this!

I'm still trying to guess which box exactly you have - Hitachi HDR255? And did you buy it new (Argos or Comet) or refurbished?

I meant to suggest this before - try booting the box with the HDD cables disconnected. Actually, T835 boxes will get stuck in a reboot loop without a HDD connected, but you should get the normal boot sequence text on the front panel - obviously this would help rule out the HDD completely. To be sure if the board really is dead, and doesn't just need a reflash, it needs to be confirmed via the serial link. BTW, see http://imageshack.us/photo/my-images...4fp5twgp5.jpg/ for a diagram of the wiring for a SCART->RS232 adaptor. I made my own a long time ago, but somebody else is selling them - http://www.ebay.co.uk/itm/Scart-to-S...item5aef79170e.

I only know of one real fix for the T835 and that is just for the 16MB835N-3 boards, involving R679 needing to be replaced. When this fails, it killed the 12v power rail (i.e. no HDD spinning up or SCART switching). The 16MB835N-4 board has a different layout in that area and doesn't even have that component from what I can remember, and obviously the symptoms are different anyway.

The only other thing I've experienced is possibly failed BGA solder joints under the CPU - try applying gentle pressure to the CPU whilst plugging it in to see if that has any affect. I've been unable to prove this, but I did have one board which would not boot unless I applied pressure to a particular corner of the CPU. Obviously reflow of the CPU doesn't really fit in with "economic repair" . Again I have no evidence, but it looks to me that the lack of a proper heatsink on the 16MB835N-4 boards may well help speed up such a failure, with good ventilation/cooling being even more important than usual.

I'm not aware of anyone who can repair these boards - a solid red LED and no serial output is about as dead as they can get, in my experience . I've made enquiries to the manufacturer regarding this particular fault, but have yet to receive any answers. Maybe it could just be a simple component failure - finding it is hard part though.

Spare boards may well be available from the manufacturer, but again, I'd be surprised if it made sense economically. It would probably be cheaper to buy a working second hand unit from ebay (any T835 would do, doesn't have to be the same brand as yours). You could then either swap the main boards or HDDs over.

Thanks for the further help and comments.

Ah, It's a Luxor DV3 bought as new from ASDA (I believe as it was a present), so I'm rapidly thinking we should return it as being not of acceptable quality under sale of goods act on the basis that a quality unit should last several years and this has only been powered for 15 months and has failed totally.

reboot without HDD attempted with no difference. I'll have a look at the RS232 output during boot as soon as I get time and post back.
Cheers for now.

Can I ask where it is usually positioned? Just curious in terms of cooling/ventilation really. Since these units have no fan, it is extremely important that nothing is placed on top of a T835 (thus blocking the air vents) with at least a couple of inches of free air above and likewise a T835 should not be placed on top of some other device which throws a lot of heat out of its top-side, like the T835 does (which would in turn cause the underside of the T835 mainboard to be hotter than normal). Enclosed cabinets/furniture is not usually the best idea. If there is inadequate ventilation, it could decrease the lifespan of the T835 mainboard and HDD. Also, operating the unit with low power mode disabled will likely reduce the lifespan as the mainboard will always be hot even in standby (although it could also be argued that multiple cooling/heating cycles that happen with low power mode on could in theory speed up any potential solder joint failures).

Maplin did sell refurbished Luxor T835 units a year or so ago. Although I think they did have 12 month warranties like the new units from Asda. It may well be worth trying to return it and I can't argue the 15 months, even if it is only guaranteed for 12 months. Having had two Playstation 3 failures (one less than a month after the warranty had run out) I can certainly understand your viewpoint, although trying to get a result under the sales of goods act can be a bit of nightmare to say the least (waste of time in my case).

The other problem you're going to have regarding the serial link is knowing if it is itself working - if you get no serial output, the mainboard could be broken, or it could be an issue with a serial link (having a working device to test the serial link on would be useful, obviously).

Of course you can ask!
It has been positioned in a cabinet with an open front with at least 200mm free space above, but sat on a Panasonic DVD recorder however this was normally off. When on it has fan cooling which blows out of the rear and would circulate freely into the room. In my experience this would be more than adequate for a well designed unit. As a comparison the hi-fi units I have are in a cabinet, stacked 5 high and only ventilated to the rear of the cabinet. Not ideal I realise but been working like this for many a year and performance is still great!

Not sure about, low power mode, it would be in the default setting.

Still no progress today at my end!

Yes, I agree - should be fine regarding ventilation. Low power enabled is the default, which is generally the recommended setting for various reasons.