My 4 year old machine started showing the odd occasional manifestation of this problem around 2 years ago now which probably explains some missed recordings over that time. I guess the conformal coating is becoming conductive before visual signs of breakdown appear. At least, tanks to your work, Les we know whats going on here!
Vic
Obviously I can only speak for the two boards I looked at but as I said in my last post the conformal coating did not appear to be conducting, and once the contaminant had been cleaned off the rogue voltages disappeared. My guess is that the crystal and the super capacitor were installed in a separate process after the rest of the components were installed and the contaminant was a product of that later process.
Whatever the reason for the contaminant we'll never know but at least it has made the repair very easy for the general public with no electronics skills required at all other than being solo on a screwdriver. My own board being two and a half years old doesn't show any symptoms whatsoever so it may be that Humax changed board supplier after a couple of years of 9200 manufacture and only older 9200s are likely to be affected.
My guess is that the crystal and the super capacitor were installed in a separate process after the rest of the components...it may be that Humax changed board supplier after a couple of years....
Or the process refined to fit all components in one step??
Or the process refined to fit all components in one step??
I say a different board supplier because my board and Coulrophobe's new board are distinctly different (but not in circuit design) to the two boards I repaired.
This possibly validates the fingerprints suspicion! Looks like generally the display/RTC boards have not been manufactured under an effective process. Some could say it's a perfect process as the boards generally last for the duration of the warranty period!
.....
Looks like generally the display/RTC boards have not been manufactured under an effective process. Some could say it's a perfect process as the boards generally last for the duration of the warranty period!
.....
If as I suspect Humax changed board supplier when the problem became apparent then at least they addressed the problem. It will be interesting to see if any of the repaired boards re-develop the fault, but as I've said before the coating looked perfect on the two boards I looked at once the contamination was removed.
what a easy fix that was, thanks a lot big Les. Might look into getting a bigger hard drive now as well, now that I have seen how easy it looks to change
Managed to pluck up the courage to give this smart solution a go but sadly it didn't work for me. At least I didn't bugger anything else up and it still 'works'! I realise it might take another attempt and I am willing to try again. Could I ask, for next time, can I test the clock without having to re-connect the hard drive?
One other thought, in cleaning the Display Panel's PCB I noticed what looked like rust around the 'rechargeable battery' (CE921) component. How likely is it that this is the cause of the problem for me? Can I get hold of a replacement one of these?
I partly ask because I've noticed recently (before doing today's clean-up) a deterioration of my clock problem - The clock has been flashing off and on (between the time and - - : - -) even when its switched on (i.e not on standby). Does this suggest another cause of the problem?
Managed to pluck up the courage to give this smart solution a go but sadly it didn't work for me. At least I didn't bugger anything else up and it still 'works'! I realise it might take another attempt and I am willing to try again. Could I ask, for next time, can I test the clock without having to re-connect the hard drive?
One other thought, in cleaning the Display Panel's PCB I noticed what looked like rust around the 'rechargeable battery' (CE921) component. How likely is it that this is the cause of the problem for me? Can I get hold of a replacement one of these?
I partly ask because I've noticed recently (before doing today's clean-up) a deterioration of my clock problem - The clock has been flashing off and on (between the time and - - : - -) even when its switched on (i.e not on standby). Does this suggest another cause of the problem?
It certainly is possible to test the clock without the HDD fitted. The 9200 will simply believe it is an earlier unit (similar to the F2-Fox-T) with no PVR facility.
I am possibly in the minority by being of the opinion that the 'Super-Capacitor' is the cause of the contamination and as such I removed it completely. I fitted in its place a standard 10v 2200uF electrolytic. This will provide power for the clock for only a few seconds (or minutes at most) in the event of a power cut. The original would probably provide power for thirty minutes or more.
I found that vigorous cleaning alone did not cure my clock, but that moving the crystal and soldering it directly to the pins of the clock IC then cutting the through board links that connect to the original solder pads for the crystal did work. It may be that the contamination had permeated through the links and into the pcb itself, either way this has worked for just over a month now.
I have to say that without Big-Les finding the cause of failure I would still be contemplating making a small pcb to carry a clock IC, crystal and capacitor to then connect to the IC2 bus in replacement of the original components.
.....
I am possibly in the minority by being of the opinion that the 'Super-Capacitor' is the cause of the contamination and as such I removed it completely. I fitted in its place a standard 10v 2200uF electrolytic. This will provide power for the clock for only a few seconds (or minutes at most) in the event of a power cut. The original would probably provide power for thirty minutes or more.
I found that vigorous cleaning alone did not cure my clock, but that moving the crystal and soldering it directly to the pins of the clock IC then cutting the through board links that connect to the original solder pads for the crystal did work. It may be that the contamination had permeated through the links and into the pcb itself, either way this has worked for just over a month now.
.....
Over a week actually, I mentioned this in the second paragraph of my instructional post.
I have seen the gunge around the top of the super capacitor but it is an almost solid substance which couldn't possibly flow onto the board, particularly with the vertical orientation of the board, so I'm afraid I can't agree with you. I admire your ingenuity in fitting a standard capacitor in place of the super capacitor but I wouldn't recommend anyone doing this as a cure. The super capacitor on Martin's board was not as good as a new one, had the gunge around the top, but it was still more than adequate for the job maintaining the time for many days. If anyone wants to replace the super capacitor then this is the one you need, but remember this will not cure the --:-- clock problem.
.....
One other thought, in cleaning the Display Panel's PCB I noticed what looked like rust around the 'rechargeable battery' (CE921) component. How likely is it that this is the cause of the problem for me? Can I get hold of a replacement one of these?
I partly ask because I've noticed recently (before doing today's clean-up) a deterioration of my clock problem - The clock has been flashing off and on (between the time and - - : - -) even when its switched on (i.e not on standby). Does this suggest another cause of the problem?
Is this "rust" just around the top edge of the plastic sleeve, if so see my post directly above.
I don't like the sound of your clock showing --:-- when switched ON, this may point to something more serious in your case. Even with the clock stopped (faulty clock board) the Hummy should show the correct time when switched ON and receiving a signal. When not receiving a signal (aerial out) the Hummy will show 13:00 when switched ON and count time from then.
I don't like the sound of your clock showing --:-- when switched ON, this may point to something more serious in your case. Even with the clock stopped (faulty clock board) the Hummy should show the correct time when switched ON and receiving a signal.
I think this behaviour (clock flashing on and off when active)has been reported several times. We saw it at the same time as the clock in standby became erratic ( sometimes displayed, sometimes failed) and the behaviour stopped when the clock in standby failed permanently and didn't return when the clock board was changed. I think the two problems are linked.
I think this behaviour (clock flashing on and off when active)has been reported several times. We saw it at the same time as the clock in standby became erratic ( sometimes displayed, sometimes failed) and the behaviour stopped when the clock in standby failed permanently and didn't return when the clock board was changed. I think the two problems are linked.
Thanks for that Martin, so maybe gdh82 simply hasn't cleaned the board well enough.
It certainly is possible to test the clock without the HDD fitted. The 9200 will simply believe it is an earlier unit (similar to the F2-Fox-T) with no PVR facility.
I found that vigorous cleaning alone did not cure my clock, but that moving the crystal and soldering it directly to the pins of the clock IC then cutting the through board links that connect to the original solder pads for the crystal did work.
Although your solution is beyond my abilities, it'll certainly make things easier testing the clock without the HDD fitted.
I think this behaviour (clock flashing on and off when active)has been reported several times. We saw it at the same time as the clock in standby became erratic ( sometimes displayed, sometimes failed) and the behaviour stopped when the clock in standby failed permanently and didn't return when the clock board was changed. I think the two problems are linked.
I must admit I can only recall the flashing clock when active has happened the once, so will be keeping an eye on it to see if it happens again. Have I got this right... a new clock board is likely to fix both problems?
Over a week actually, I mentioned this in the second paragraph of my instructional post.
I was going to say 'days', but didn't want to over-egg the capabilities of the 'Super-Capacitor'!
Despite reading your initial instructional post, I hadn't noticed that. I apologise for not taking more notes.
I have seen the gunge around the top of the super capacitor but it is an almost solid substance which couldn't possibly flow onto the board, particularly with the vertical orientation of the board, so I'm afraid I can't agree with you.
I know that very few other people agree with me and I don't want to start a discussion that I don't have the educational clout to backup - but... Over 25 years of repairing consumer electronics equipment has given me a deep distrust of any electrolytic capacitor showing any signs of distress. These can and often do measure very well on both capacitance meters and E.S.R. (Equivalent Series Resistance) meters despite clear signs of leakage. The electrolyte can be very corrosive (corroding copper circuit tracks completely in extremely short periods of time) and can penetrate deep into soldered joints by capillary action, spreading across large areas remarkably quickly. It was not unusual to find that the initial reported failure of an item of equipment was actually the secondary cause of failure, the initial cause being a leaky capacitor which on its own produced no symptoms. Had that capacitor not been replaced, some other failure would have occurred eventually which would be expected to be covered under our repair warranty. Much cheaper to replace the electrolytic capacitor in the first place and be sure of a lasting repair.
I know you've done a lot of work in this area, and I know you've done a lot of tests in the clock circuitry, and I don't want you to think I don't appreciate your generosity in sharing your cure, as I do.
I'll say again: Thanks for all your work in locating the area of the failure.
It could be that my long held prejudice against electrolytics is holding me back... But I'll personally sleep better for knowing it is no longer going to cause me problems.
I was going to say 'days', but didn't want to over-egg the capabilities of the 'Super-Capacitor'!
Despite reading your initial instructional post, I hadn't noticed that. I apologise for not taking more notes.
I know that very few other people agree with me and I don't want to start a discussion that I don't have the educational clout to backup - but... Over 25 years of repairing consumer electronics equipment has given me a deep distrust of any electrolytic capacitor showing any signs of distress. These can and often do measure very well on both capacitance meters and E.S.R. (Equivalent Series Resistance) meters despite clear signs of leakage. The electrolyte can be very corrosive (corroding copper circuit tracks completely in extremely short periods of time) and can penetrate deep into soldered joints by capillary action, spreading across large areas remarkably quickly. It was not unusual to find that the initial reported failure of an item of equipment was actually the secondary cause of failure, the initial cause being a leaky capacitor which on its own produced no symptoms. Had that capacitor not been replaced, some other failure would have occurred eventually which would be expected to be covered under our repair warranty. Much cheaper to replace the electrolytic capacitor in the first place and be sure of a lasting repair.
I know you've done a lot of work in this area, and I know you've done a lot of tests in the clock circuitry, and I don't want you to think I don't appreciate your generosity in sharing your cure, as I do.
I'll say again: Thanks for all your work in locating the area of the failure.
It could be that my long held prejudice against electrolytics is holding me back... But I'll personally sleep better for knowing it is no longer going to cause me problems.
Well I appreciate your concerns mkstevo, I had a big capacitor blow in a Panasonic projector and that made a hell of a sticky mess, but the super capacitor in the Hummy is working under very easy conditions. The current it is supplying to the clock in standby is so small that even a large ESR is no problem. I can't say exactly how long the super capacitor will keep the clock going but on my board I can say that it is greater than one week (I think two actually) and less than five weeks.
From the measures you had to go to to get your clock going I would say that your board was in a very much worse condition than the two boards I fixed.
Servisol IPA 170 Isopropyl Alcohol from Maplins. I sprayed some into the lid and then used cotton buds. I could see some 'deposits' on the back on the board. I cleaned both sides 2-3 times until the buds were no loner getting 'gunked'.
For next time, I imagine I'll need to re-insert the aerial lead (to provide time information) when I come to test. Is that right? Or should it display 00:00 if its fixed? Thanks again.
To add my twopennys worth. I cleaned my board, a few weeks ago, with Sergical Spirit.
Did not work even though I gave it a very thorough clean, including the gunge around the capacitor.
Have finally got it stripped again and gave it an even more thorough cleaning and hay presto, all works fine.
I think all you need is patience. Keep cleaning and it will work.??
To add my twopennys worth. I cleaned my board, a few weeks ago, with Sergical Spirit.
Did not work even though I gave it a very thorough clean, including the gunge around the capacitor.
Have finally got it stripped again and gave it an even more thorough cleaning and hay presto, all works fine.
I think all you need is patience. Keep cleaning and it will work.??
Thanks for that feedback egros.
Quote form my instructional post.
The success of this repair will depend on how thoroughly you do the cleaning.
.....
I could see with my lab equipment that the oscillations were getting stronger with each cleaning process.
.....
For next time, I imagine I'll need to re-insert the aerial lead (to provide time information) when I come to test. Is that right? Or should it display 00:00 if its fixed? Thanks again.
If you've fixed it the clock will start at 13:00 when the Hummy boots to Standby from mains switch-on, aerial connected or not. If you then switch on with aerial connected and receiving a broadcast signal then the time will be corrected to 'now'. If you switch on with no aerial connected the time will continue to count from 13:00. Of course if you've not fixed it the display will continue to show --:--.
Comments
Obviously I can only speak for the two boards I looked at but as I said in my last post the conformal coating did not appear to be conducting, and once the contaminant had been cleaned off the rogue voltages disappeared. My guess is that the crystal and the super capacitor were installed in a separate process after the rest of the components were installed and the contaminant was a product of that later process.
Whatever the reason for the contaminant we'll never know but at least it has made the repair very easy for the general public with no electronics skills required at all other than being solo on a screwdriver. My own board being two and a half years old doesn't show any symptoms whatsoever so it may be that Humax changed board supplier after a couple of years of 9200 manufacture and only older 9200s are likely to be affected.
My 9200 is working properly again with just an eggcup of isopropyl and a dozen cotton buds
Genius - thanks again.
As a matter of interest how old is your machine?
I say a different board supplier because my board and Coulrophobe's new board are distinctly different (but not in circuit design) to the two boards I repaired.
This possibly validates the fingerprints suspicion! Looks like generally the display/RTC boards have not been manufactured under an effective process. Some could say it's a perfect process as the boards generally last for the duration of the warranty period!
Has anyone looked under the main PCB of the 9200?
Vic
If as I suspect Humax changed board supplier when the problem became apparent then at least they addressed the problem. It will be interesting to see if any of the repaired boards re-develop the fault, but as I've said before the coating looked perfect on the two boards I looked at once the contamination was removed.
And so it did with mine!
Vic
One other thought, in cleaning the Display Panel's PCB I noticed what looked like rust around the 'rechargeable battery' (CE921) component. How likely is it that this is the cause of the problem for me? Can I get hold of a replacement one of these?
I partly ask because I've noticed recently (before doing today's clean-up) a deterioration of my clock problem - The clock has been flashing off and on (between the time and - - : - -) even when its switched on (i.e not on standby). Does this suggest another cause of the problem?
It certainly is possible to test the clock without the HDD fitted. The 9200 will simply believe it is an earlier unit (similar to the F2-Fox-T) with no PVR facility.
I am possibly in the minority by being of the opinion that the 'Super-Capacitor' is the cause of the contamination and as such I removed it completely. I fitted in its place a standard 10v 2200uF electrolytic. This will provide power for the clock for only a few seconds (or minutes at most) in the event of a power cut. The original would probably provide power for thirty minutes or more.
I found that vigorous cleaning alone did not cure my clock, but that moving the crystal and soldering it directly to the pins of the clock IC then cutting the through board links that connect to the original solder pads for the crystal did work. It may be that the contamination had permeated through the links and into the pcb itself, either way this has worked for just over a month now.
I have to say that without Big-Les finding the cause of failure I would still be contemplating making a small pcb to carry a clock IC, crystal and capacitor to then connect to the IC2 bus in replacement of the original components.
Thanks Big-Les.
Over a week actually, I mentioned this in the second paragraph of my instructional post.
I have seen the gunge around the top of the super capacitor but it is an almost solid substance which couldn't possibly flow onto the board, particularly with the vertical orientation of the board, so I'm afraid I can't agree with you. I admire your ingenuity in fitting a standard capacitor in place of the super capacitor but I wouldn't recommend anyone doing this as a cure. The super capacitor on Martin's board was not as good as a new one, had the gunge around the top, but it was still more than adequate for the job maintaining the time for many days. If anyone wants to replace the super capacitor then this is the one you need, but remember this will not cure the --:-- clock problem.
Is this "rust" just around the top edge of the plastic sleeve, if so see my post directly above.
I don't like the sound of your clock showing --:-- when switched ON, this may point to something more serious in your case. Even with the clock stopped (faulty clock board) the Hummy should show the correct time when switched ON and receiving a signal. When not receiving a signal (aerial out) the Hummy will show 13:00 when switched ON and count time from then.
Thanks for that Martin, so maybe gdh82 simply hasn't cleaned the board well enough.
Although your solution is beyond my abilities, it'll certainly make things easier testing the clock without the HDD fitted.
I must admit I can only recall the flashing clock when active has happened the once, so will be keeping an eye on it to see if it happens again. Have I got this right... a new clock board is likely to fix both problems?
I'm hoping so too. I'll give it another bash soon and post my results...
I was going to say 'days', but didn't want to over-egg the capabilities of the 'Super-Capacitor'!
Despite reading your initial instructional post, I hadn't noticed that. I apologise for not taking more notes.
I know that very few other people agree with me and I don't want to start a discussion that I don't have the educational clout to backup - but... Over 25 years of repairing consumer electronics equipment has given me a deep distrust of any electrolytic capacitor showing any signs of distress. These can and often do measure very well on both capacitance meters and E.S.R. (Equivalent Series Resistance) meters despite clear signs of leakage. The electrolyte can be very corrosive (corroding copper circuit tracks completely in extremely short periods of time) and can penetrate deep into soldered joints by capillary action, spreading across large areas remarkably quickly. It was not unusual to find that the initial reported failure of an item of equipment was actually the secondary cause of failure, the initial cause being a leaky capacitor which on its own produced no symptoms. Had that capacitor not been replaced, some other failure would have occurred eventually which would be expected to be covered under our repair warranty. Much cheaper to replace the electrolytic capacitor in the first place and be sure of a lasting repair.
I know you've done a lot of work in this area, and I know you've done a lot of tests in the clock circuitry, and I don't want you to think I don't appreciate your generosity in sharing your cure, as I do.
I'll say again: Thanks for all your work in locating the area of the failure.
It could be that my long held prejudice against electrolytics is holding me back... But I'll personally sleep better for knowing it is no longer going to cause me problems.
Well I appreciate your concerns mkstevo, I had a big capacitor blow in a Panasonic projector and that made a hell of a sticky mess, but the super capacitor in the Hummy is working under very easy conditions. The current it is supplying to the clock in standby is so small that even a large ESR is no problem. I can't say exactly how long the super capacitor will keep the clock going but on my board I can say that it is greater than one week (I think two actually) and less than five weeks.
From the measures you had to go to to get your clock going I would say that your board was in a very much worse condition than the two boards I fixed.
What cleaning agent are you using?
Servisol IPA 170 Isopropyl Alcohol from Maplins. I sprayed some into the lid and then used cotton buds. I could see some 'deposits' on the back on the board. I cleaned both sides 2-3 times until the buds were no loner getting 'gunked'.
For next time, I imagine I'll need to re-insert the aerial lead (to provide time information) when I come to test. Is that right? Or should it display 00:00 if its fixed? Thanks again.
Did not work even though I gave it a very thorough clean, including the gunge around the capacitor.
Have finally got it stripped again and gave it an even more thorough cleaning and hay presto, all works fine.
I think all you need is patience. Keep cleaning and it will work.??
Thanks for that feedback egros.
Quote form my instructional post.
If you've fixed it the clock will start at 13:00 when the Hummy boots to Standby from mains switch-on, aerial connected or not. If you then switch on with aerial connected and receiving a broadcast signal then the time will be corrected to 'now'. If you switch on with no aerial connected the time will continue to count from 13:00. Of course if you've not fixed it the display will continue to show --:--.