prpr
Well-Known Member
My HD Fox has been developing a fault over the last few months...
It started out with occasional blocking on the DVB-T2 mux's channels. Curious I thought, but OK on services on all the DVB-T muxes. I looked at the signal strength on all and they were varying more than you might expect. Unlikely to be the aerial feed but you never know. Investigating that particular can got kicked down the road.
The next time I looked (this box is usually used as source data for the tunefix-update package), the blocking had got much worse (still on DVB-T2 only) and the signal levels were varying wildly on all - stuff that should have been 70% was anything between 30% and 93%. I suspected imminent death.
That happened on Wed., just after it provided the data for this week's updates, but in the form of the infamous HDMI green screen after the Humax startup logo. The box itself still works, but I can't connect the SCARTs to my computer monitor to see to operate it. So I needed a new unit.
I'd already trawled through e8@y earlier and identified a few contenders, so bought one of those - nearly new and very little use (and the bonus is the genuine remote is virtually brand new). It's got a half-ripped off sticker on the bottom saying "Property of Forbes ..." (maybe Rentals) and a phone number for maintenance.
It's obviously been used in the London area as it was tuned to Crystal Palace within the last month, although without this week's changes, and there was current residual data in the EPG.
I tried an Auto-tune and it made a hash of it, with 18 muxes visible. I reset and did it manually and it receives all 7 muxes from Mendip quite happily, with full EPG data and no issues that I have found so far.
The intriguing thing is that it has firmware 1.00.08 from 4th Feb 2010, which wasn't listed on the Wiki, and some menu items I've never seen before on the Hidden Menu:
Note the "Change Theme" menu which just had 2 items - the one shown and a blank bar - I didn't investigate further; the lack of anything resembling what we might use in the UK for the "Operator Setting"; and the "Fusing Info".
I can't think of anything else to look at on this before blowing it away and loading 1.03.02 CF.
Back to the failed box, I've had the lid off and measured the power supply voltages and they are significantly unstable from what I would expect. It seems the 8 pin connector has 3x 3.3V and 1x 12V with 4 commons. All vary from nominal with at least half a volt of AC, on-load. Off-load (connector unplugged) it's a lot worse - the 12V was nearly 16V. Nothing obviously wrong with capacitors or anything else on the PSU board, but I don't have any expertise with switched mode power supplies, nor any usable test gear apart from a multi-meter ('scope is broken!).
I expect this is the cause of the mis-operation though. I suppose I could take the new one to bits as well to compare, but haven't.
It started out with occasional blocking on the DVB-T2 mux's channels. Curious I thought, but OK on services on all the DVB-T muxes. I looked at the signal strength on all and they were varying more than you might expect. Unlikely to be the aerial feed but you never know. Investigating that particular can got kicked down the road.
The next time I looked (this box is usually used as source data for the tunefix-update package), the blocking had got much worse (still on DVB-T2 only) and the signal levels were varying wildly on all - stuff that should have been 70% was anything between 30% and 93%. I suspected imminent death.
That happened on Wed., just after it provided the data for this week's updates, but in the form of the infamous HDMI green screen after the Humax startup logo. The box itself still works, but I can't connect the SCARTs to my computer monitor to see to operate it. So I needed a new unit.
I'd already trawled through e8@y earlier and identified a few contenders, so bought one of those - nearly new and very little use (and the bonus is the genuine remote is virtually brand new). It's got a half-ripped off sticker on the bottom saying "Property of Forbes ..." (maybe Rentals) and a phone number for maintenance.
It's obviously been used in the London area as it was tuned to Crystal Palace within the last month, although without this week's changes, and there was current residual data in the EPG.
I tried an Auto-tune and it made a hash of it, with 18 muxes visible. I reset and did it manually and it receives all 7 muxes from Mendip quite happily, with full EPG data and no issues that I have found so far.
The intriguing thing is that it has firmware 1.00.08 from 4th Feb 2010, which wasn't listed on the Wiki, and some menu items I've never seen before on the Hidden Menu:
Note the "Change Theme" menu which just had 2 items - the one shown and a blank bar - I didn't investigate further; the lack of anything resembling what we might use in the UK for the "Operator Setting"; and the "Fusing Info".
I can't think of anything else to look at on this before blowing it away and loading 1.03.02 CF.
Back to the failed box, I've had the lid off and measured the power supply voltages and they are significantly unstable from what I would expect. It seems the 8 pin connector has 3x 3.3V and 1x 12V with 4 commons. All vary from nominal with at least half a volt of AC, on-load. Off-load (connector unplugged) it's a lot worse - the 12V was nearly 16V. Nothing obviously wrong with capacitors or anything else on the PSU board, but I don't have any expertise with switched mode power supplies, nor any usable test gear apart from a multi-meter ('scope is broken!).
I expect this is the cause of the mis-operation though. I suppose I could take the new one to bits as well to compare, but haven't.
