As far as I'm aware you're the first person to report a re-fail. I'm not sure why you are seeing --:-- occasionally on playback, I would expect elapsed time data to keep the clock running the same as real time data does when watching live TV. Is the white ribbon cable fully inserted in its socket?

I have seen exactly the reported behaviour on playback just before the clock failed in standby.

Thanks for that Martin, presumably you have not seen --:-- in playback since I repaired it though? If that is the case then I think Punker just needs to do a bit more cleaning hopefully.

I see that several people have used a toothbrush to do the cleaning, I really don't recommend this. I would much prefer to see a kids paint brush or similar being used, this sort of brush will allow you to clean around and under the crystal and super capacitor without fear of damage particularly to the crystal. The real problem area is around the connections between the chip and the crystal.

Punker,
I think the component you refer to that has come unstuck is the crystal (silver cylindrical component). This is stuck down with a dab of silicone rubber to give it mechanical support as its leads are a bit thin, it doesn't need to be in contact with the surface of the board.

No problems although currently the box isn't being used much.

Joined the forum just to say thanks! By following the concise information provided by Big-les I managed to successfully repair 'the 9200 --:-- clock problem' we had started to experience. Before commencing work I took a photo of both the front and the back of the board to illustrate exactly how ours looked. I cleaned it with some cotton buds soaked in Isopropanol alcohol and used a fine brush to get into the nook & crannies. I finished by gently blow drying it. Everything is now working as it was before the problem arose.

Thanks again.

I've re-cleaned and it is now working fine again. not sure why it failed again?? The playback problem has gone too! I just left the crystal unattached from the board. Next time I go in there (probably to fit the HDD cable mod) I will put a drop of glue gun glue to attach it back on. Thanks for you help everyone

More thanks to Big-les, finally got around to fixing both mine and my Mum's clock problem. The contamination on my Mum's was particularly bad... Check out the black marks on the front and back of the board.

Both seem fine and black marks disappeared after cleaning with some cotton wool buds, a brush and some surgical spirit!!

So thanks again,

baz

My 9200T started to have the clock problem yesterday - and it was bought new in April 2007.
Today it all works fine thanks to the Big-les repair.

I could not see any contamination but a little muck came off on the first cotton bud from the component side.

I used RS components Cleaning fluid 513-679 which I use normally for cleaning tape heads and CDs or indeed anything electrical. The spray can does not say what it contains but online RS says mainly it is PROPAN-2-OL with other ingredients found in aerosol cans for propellant.

Regards,
J

It turns out to be Isopropyl alcohol....
J

Another thank you for Big Les. My unit started to have intermittent clock failures recently so I have just given the board a clean up with Servisol cleaning spray and cotton buds. There was no visible deposit but the buds did become slightly soiled so I assume there was a film of something. The spray does cool the board quite markedly and condensation appeared after repeated applications. I warmed it to above dew point with a hair dryer and refitted it. As the failure was occasional I cannot yet say if it's fixed, but so far, so good...

Sadly I must report that the clock was back to --:-- yesterday. It's okay this morning but obviously still prone to failure. I'll investigate a replacement board before trying a clean up again just to have all the information to hand...

Try using surgical spirit as per my instructions.

Big-les, I probably shall but I wanted to know if, and for how much, a new PCB was available before gutting the front end of the unit again. It's such a rats' nest of cables under my TV that I venture in there only when necessary. Thanks again for all then advice.

Last I heard a new board was £30 direct from Humax.

I'm still getting the --:-- clock problem but it's ok if i leave the box on for a few days solidly. I electronics guy at work suggested I change the capacitors on the mains/power in board as he says that they are normally cheap components and only work well for a while and he's changed them on other AV equipment and solved lots of other problems. Would this be worth doing when i go in again (5th time) to clean the board?

There are many PVRs (and other AV/TV equipments) that are frequently reported to suffer PSU/capacitor failure.
The Humax range however, has rarely if ever been reported for this issue.

I've experienced this recurring problem on a couple of 9200's and solved it by
removing the 12pf capacitor on pin 2 of the RTC chip.

According to the NXP data sheet this cap isn't actually required since the chip
already has an embedded cap on pin 2.

I suspect that Humax added the cap to trim the oscillator frequency
but as the application note clearly shows, any trim capacitance should be on pin 1
not pin 2.

I doubt there is any capacitor problem in your Hummy so my answer is DON'T mess with the power supply. I have seen this capacitor problem on a couple of computer motherboards of a certain make, the capacitors were actually leaking gunge from the swollen tops. The computers were running 24/7 and never faulted. While I don't deny these large value capacitors can fail in switch mode power supplies I do think the problem is being exaggerated and becoming an urban myth.

Without going back to my notes (very busy at the moment) if I remember correctly that capacitor has very little influence on frequency, considerably larger values have very little effect. In fact I think on the boards I looked at the oscillator stopped before I could drag the frequency down to that of the crystal. The only way I can see removing that capacitor would help is if the contamination problem affecting pin 1 was still there. The clock in standby actually runs fast which means the Hummy switches ON earlier rather than later to make a recording.

Ok thanks for your advice (and nvingo)

Another satisfied customer here!
Thanks to Big-les I now have a fully functioning PVR again
I started having the problem since my summer holiday - I turned everything in the house off at the socket for a fortnight but since being back the clock wasnt displaying on standby and I kept missing recordings.
The whole process only took 20 minutes or so and also gave me the opportunity to run the hoover over the inside of my Hummy - The dust inside the thing was incredible but it is 6 years old!

Thanks again for the hard work.

£30.70 fully inclusive to be totally up-to-date Big-les. I am afraid I took the lazy way out and ordered a new PCB assembly. The PVR is five years old and the clock segments almost invisible in normal room lighting anyway, so I regard it as an investment in a device that I mean to keep. Having upgraded it to 500Gb hard drive I have hardly begun to fill it it up!

Many thanks for your kind help - I still have the PCB and, who knows, it might come in handy...

whilst following guidelines on cleaning the back of the clock on my humax pvr -9200T i think I've damaged the Y 921 crystal component ....when I put it all back and turned on ...nothing at all...nothing is working .........not knowing the technical side of things ....do I need now to buy new RTC ??? many thanks

If you have damaged the crystal, a new one can be purchased from:

http://uk.farnell.com/ael-crystals/x...khz/dp/9509682

many thanks peterham....i cleaned the the board as instructed using surgical spirits....i thought I'd damaged the chrystal....but soon realised the switch at back of pvr was off ! ..I must have knocked it when fiddling around back of unit.....wonder upon wonders the clock was working again ...its still on this morning and hopefully will stay on ....I was so dismayed initially cos I want to go away for a couple of weeks and didn't want to leave the unit on constantly to record future programmes....didn't realize how much I depended on this wonderful machine until ' it broke'......I cant stand adverts and have got so used to fast forwarding through them on recordings the thought of watching 'real time' tv horrified me... thanks to all for the advice on cleaning the clock.....

just read another posting above about the crystal being secured with silicone ...thats why I thought I'd damaged mine ....i saw the silicone had come away from the board after I cleaned it and thought the worse...