My 9200T standby clock also went --:-- and its only two and a half years old.

No reply from Humax.

So as a former TV Equipment Development Engineer I took on this problem determined to crack it.

It turns out to be the 32.768kHz resonator.

A suitable replacement can be obtained from RS components
http://uk.rs-online.com/web/5476985.html
stock no: 547-6985 min qty 10 @ £0.21ea.

This item has good frequency stability and meets the spec for the PCF8563 clock chip.

It is easily replaced using a Maplin desolder pump, and antistatic discharge prevention should be used to protect the whole machine.

My 9200T standby clock also went --:-- and its only two and a half years old.

No reply from Humax.

So as a former TV Equipment Development Engineer I took on this problem determined to crack it.

It turns out to be the 32.768kHz resonator.

A suitable replacement can be obtained from RS components
http://uk.rs-online.com/web/5476985.html
stock no: 547-6985 min qty 10 @ £0.21ea.

This item has good frequency stability and meets the spec for the PCF8563 clock chip.

It is easily replaced using a Maplin desolder pump, and antistatic discharge prevention should be used to protect the whole machine.

Any theories as to why the resonator is failing?

Is there anyone who would be prepared to offer a repair service for the clock boards? The replacement component is cheap so I would have thought something like £10 inclusive of p&p would be a nice little side line for somebody.

Sounds very promising, certainly worth a punt for a couple of quid (fortunately I won't have to worry about carriage charges) so I will be ordering one one of those (or 10) this week and will post the results.

would any of these do ?

http://cpc.farnell.com/jsp/search/br...h+crystal&Ntx=

just in case RS don't have them in stock

http://cpc.farnell.com/ael-crystals/...khz/dp/SC08198 appears to match on size (8 x 3) and capacitance (12.5pF)

Strange, having said that I would get the resonator, I put the super capacitor back on my board and the clock worked fine all last night. However, it gave up the ghost this morning, so the part is on order from RS.

[quote=WPP;33209642]would any of these do ?

http://cpc.farnell.com/jsp/search/br...h+crystal&Ntx=

just in case RS don't have them in stock/QUOTE

Good point, but Farnell do not give a vital resonator spec the ESR, if its too high it might not work.

The PCF8563 data sheet (page 19) specifies a max value for the ESR (Equivalent Series Resistance) of the resonator of 40 k ohm, if its greater it may fail to oscillate, some resonators are much higher.

Also in the spec a load cap of 10pF. If the resonator used is dsigned for a different load, the frequency may cause the clock to run fast or slow.

Just an idea, it could be a bad batch of resonators bought in bulk.

are you sure it's not the capacitor in that case ?

I checked out the "super capacitor" and it was perfectly ok, its funtion seems to be to supply the clock chip with a constant 5V supply during transition between power down and the start up of the standby power, about fifteen seconds. The drop in voltage over that time is tiny and hardly measurable considering the value of the capacitor is 0.22F (220,000 uF) and the current drain is 200uA (from data sheet).

Could be the faulty resonators are affected by thermal shock.

Darned if I am sure about anything at the moment

Don't really suspect the super-capacitor. After all, when I checked its voltage, it was 4.8v, more than enough for the clock chip, and it had probably taken me 10 minutes to go from power-down to measuring the voltage. In my case, loss off the clock had always been immediately the unit was put into standby.

Tuesday and Wednesday, the clock is running again. I have the new resonator, but am waiting to see if the clock goes off again before I consider fitting it.

MercuryMan: I stand corrected on the Farnell resonator, those are valid concerns. As for the failure modes of the resonator, no idea, I will ask the failure modes guys at work if they have any ideas.

Sad to say, the replacing the resonator didn't work for me. As I indicated previously, it now seems to be in a mode where sometimes the clock works for a while, sometimes it doesn't; but changing the resonator, hasn't changed that.

alan-p-brown: You may have a genuine intermittent fault, most likely I would expect is a "dry joint" or minute solder splash causing an intermittent short, on the clock card, from manufacture and it has sarted to cause trouble now. I have seen those problems but it is rare that they get past inspection and sold. Also the flat ribbon cable connecting the clock card to the mother board is vulnerable from being torn across and to insulation removal on the chassis hole edges.

In my experience under normal operating conditions an intermittent chip is extremely rare, failure is usually permanent.

At the risk of sounding like "I am allright Jack", my 9200T is working fine, all as it should be, ever since I replaced the resonator.

any chance of some photo's of the part and a suggested replacement procedure for those of us who are thinking of giving it a try ?

The link on MercuryMan's post at http://www.digitalspy.co.uk/forums/s...9&postcount=27 shows a picture of the component, and the post says to use a Maplin desolder pump.

Doesn't look like the sort of thing to attempt unless you know what you are doing, or are doing it on a spare board after getting an official replacement from Humax.

well the USB mod was easy enough given the pictures http://humaxdisk.wikispaces.com/Disk+Cabling+and+Mods

and I have antistatic mats, wristbands, desolder tools, soldering irons and have worked on PC boards before now

I just like to see what other people did first so I know what I'm dealing with and what to watch out for before I strip my hummy down and give it a go

a picture paints a thousand words and seeing the component in situ means I don't have to take my hummy apart to see what the problems might be

basically if it looks like a pain in the a*se to get at I probably won't bother but if it's fairly simple to get at then I'll give it a shot

and here's a funny thing

we've still got our hummy set to turn itself off after all the records are done, which it does quite successfully

but last night the standby clock actually started all on it's own

I was amazed

so I left it for 30 minutes to see if it would keep time but it lost 4 minutes over the period so I turned it off

turning back on got the same "--:--" that I'm used to

I have the same problem - it started last week. I don't have the technical expertise to replace the component. Are there any other suggestions about what I might do to put it right?

Eric

Buy a clock board from Humax who are charging about £30.

does anyone have details of who to contact and what part number to ask for ?

My Humax did the same about 3 months ago - i get the dashes instead of the time in standby. Annoying when you go on holiday and have to leave it on. What's the prevailing opinion then? Get a £30 replacement pbr board from humax?

well I bit the bullet phoned the support guys on 08446698800 and told them my 9200T was displaying --:-- in standby and the nice man at t'other end promptly told me the clock card was failing and sold me a replacement card for £30.70 inc delivery & VAT

since which phone call the standby clock on our Hummy has worked perfectly

but I'm still replacing it when then new one arrives

Another clock failure here. We've noticed that quite a few recordings have been missed recently and last week I noticed the clock flashing the time, and then "-- --" and also "-- --" when in standby.

I'm happy to try the repair myself replacing the crystal.

Does anyone have any spare they could sell me rather than ordering 10 from RS?

As a product sold in the UK has to be "fit for purpose" Humax should be supplying exchange clock boards either FOC or for a small fee to cover P&P.

Just because its out of warranty doesn't mean that Humax can shirk their responsibilities under UK & EU Law.

I was wondering the same thing.

This seems to be a design defect of some kind due to the number of people reporting the same issue.

Does it not come down to what time period we would expect the Humax box to last for?

So does "fit for purpose" mean the device should last 2 years, 5 years or 10 years?

I purchased my Humax when they first came out, which was around Oct 2005 I believe, so it's coming up to 4 years.