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The title of this topic is “9200 Clock Problem – 2nd Time“.
Cleaning the board on my machine fixed it the first time but the cure only worked for a couple of months. It did not work a second time, replacing the crystal did. The purpose of this forum is to put information out there. Is the only alternative to the cleaning fix to purchase an entire board for £30+?
Many home electronics and computer enthusiasts who would search the web for a fix for this problem and are the sort of person who can change a component on a PCB. The crystal is not a multi legged surface mount chip and it costs less than £2. If I was giving full repair instructions I would of course give all the usual warnings and disclaimers.
I have no axe to grind. I put the information on the forum to pass it on to other users even though it is buried as the nth posting on a one year old topic. Let’s see if there is any response.
Pottsy – 3 minutes ago »
The title of this topic is “9200 Clock Problem – 2nd Time“.
Cleaning the board on my machine fixed it the first time but the cure only worked for a couple of months. It did not work a second time, replacing the crystal did. The purpose of this forum is to put information out there. Is the only alternative to the cleaning fix to purchase an entire board for £30+?
Many home electronics and computer enthusiasts who would search the web for a fix for this problem and are the sort of person who can change a component on a PCB. The crystal is not a multi legged surface mount chip and it costs less than £2. If I was giving full repair instructions I would of course give all the usual warnings and disclaimers.
I have no axe to grind. I put the information on the forum to pass it on to other users even though it is buried as the nth posting on a one year old topic. Let’s see if there is any response.
Of course it is possible that you damaged the crystal on your second attempt at the repair. Until I am told different by the owners of the two boards I repaired I will assume those boards are still working so doing the job correctly in the first place effects a lasting repair.
I can accept that electrochemical processes can occur on PCBs. That is the reason manufacturers go to the trouble of washing off the flux residues after soldering. I have even experienced short circuits between tracks on a multi layer board caused by metal growth.
Can you not accept that crystals can degrade over time?
You have slated my posts as “irrelevant” and suggested that I “damaged the crystal” on my second attempt at cleaning the board.
I suggest that the moderator promote these exchanges to a new topic, so that they can be found by most searches, and let the members decide if I wasted my time by posting my experience.
Of course components can fail but crystals and ICs are very reliable and in my experience these components only fail after human intervention. Consider this, there are millions of quartz clocks knocking around (I have about 8 without looking, some very old) all with the same or similar crystal to that in the 9200, do they fail or degrade, I doubt it. The only failures I have seen in quartz clocks have been poor battery contacts.
I have not slated your posts but the content of your post #12 is rubbish and therefore irrelevant. The oscillator does not need to be triggered to start, the oscillator is free running providing nothing is stopping it from running, in this case a voltage generated by some chemical process. When I cleaned Martin’s board the super capacitor (there is no “standby battery”) had been removed so obviously could not have had any influence. It is inconceivable that the tens, maybe hundreds, of people that have successfully repaired their clock boards have done it due to some fluke of the super capacitor somehow triggering the oscillator into life. If you have any hard evidence to support your theory in post #12 then I’ll be pleased to hear it.
I investigated, solved and came up with a solution to the 9200 clock problem that would allow almost anybody to get their 9200 fully functioning again. Before going public I simulated the problem on Martin’s board and also on a test circuit on the bench to be sure I’d not missed anything. I did this for my own interest and shared it with the Humax community. I do not intend to rubbish your posts, I simply want the readers to know the facts (not theory’s) and then they can decide for themselves if changing components is worthwhile. Of course there might be the odd board that has a component problem, yours might be it, but of all the people that have posted here and on DS not one that I can recall has failed to repair their 9200 using my instructions.
How many people have failed to fix this problem and fitted a replacement board board at a cost of £32 ? Are they still available?
Why is there a video on YouTube on how to replace the board?
On my card the “super capacitor” is a battery. Does nobody from Humax read these posts.
Of course the oscillator does not need to be triggered — when it is working.
In the end it all comes down to the fact that I had a faulty card, cleaning didn’t fix it. I replaced the crystal at a cost of £2 and it is now working.
Why is this topic so hard to find with the most common search terms?
Quote:How many people have failed to fix this problem and fitted a replacement board board at a cost of £32 ?Presumably none that have read my instructions and posted, or at least they haven’t posted as such. If someone had a problem I tried to help them out.
Quote:Why is there a video on YouTube on how to replace the board?I’m sure PCRowan was just trying to be helpful, he has at least now linked to my instructional thread on this forum, originally he didn’t. There is much more feedback on my original DS thread.
Quote:On my card the “super capacitor” is a battery.That’s an interesting one. Was your 9200 second hand, is it possible someone has tinkered with the board before you got it?
Quote:Why is this topic so hard to find with the most common search terms?My original DS thread comes up top of the list with a Google search of ‘9200 clock problem’, PCRowan’s video second.
A search of this forum for 9200t clock problem shows 2nd item in relevant posts as this FAQ item My 9200t shows –:– in Standby (link)
I don’t see any benefit in this discussion continuing in this vein. I am minded to lock the thread if it continues.
aldaweb – 51 minutes ago »
A search of this forum for 9200t clock problem shows 2nd item in relevant posts as this FAQ item My 9200t shows –:– in Standby (link)
I don’t see any benefit in this discussion continuing in this vein. I am minded to lock the thread if it continues.
Please do, I really don’t have the time for arguing the toss about a problem that has been solved and proved to have been solved many times over.
I have never said that your fix doesn’t work. I think that your explanation of a mysterious contamination that takes 5 years to have any effect, is just a theory. Why do all the millions of RTCs in the cheapest of domestic equipment not suffer this contamination. Are Humax circuit boards so poorly made as to be the only ones to suffer this problem?
When the oscillator stops for whatever reason, the RTC chip is sitting there powered by the mains supply or, when the board is unplugged or mains lost, powered by the supercapacitor or battery, (it really is irrelevant which). The oscillator will be latched up. As you say the input pin is a very high impedance and will just drift until the output hits a supply rail and latches up. The oscillator will not restart until the power is removed or the input is pulled in the opposite direction by what? Static electricity, a scope probe, cleaning? Power cannot be removed without disconnecting the power source.
Why did the oscillator stop? Why did cleaning not fix my board a 2nd time? Remember the other members who started this topic and the title.
I don’t have a supply of duff boards to test these theories. I simply reported my experience that replacing the crystal fixed my board.
My complaint was that search terms on this forum did not find this topic — not on the internet.
Enough
Pottsy – 8 minutes ago »
My complaint was that search terms on this forum did not find this topic — not on the internet.
Enough
You obviously did not take the time to search the FAQ section or you would have found the FAQ item I linked to above, which could also be found by a search of the forums.
Thread locked
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