Well done for sticking with it and getting the PVR going again; even if your soldering isn't, your tenacity is impressive! Might be worth applying a few strategically-placed blobs of Araldite for mechanical stability/to prevent possible shorts. Looks like the cap is the correct way round with...
Correct - the component immediately to the right of the 4u7 cap is the 10k resistor shown in parallel with it in the circuit diagram. I measured the three resistors of interest with a DMM when determining the circuit (see post #91). But beware! These are ant-sized components and can easily...
That looks horrible! Certainly a degree of skill and experience with a soldering iron is called for when replacing the cap - but plentiful tips on how to achieve a successful outcome are to be found in the many pages of this topic. New readers please note!
Excellent! Hearing stories like this one makes all those hours I spent nailing this one even more worthwhile. Well done for persevering; there's a lot to be said for the "what-the-hell" approach! As you found, it often pays dividends.
Another satisfied customer - congratulations!
The attached shows what's really going on with the HDD supplies (top: 12V; bottom: 5V) - in this case it all comes good after the dud cap has warmed up enough (HDD supplies switch off at end as this was a "mains-on" start).
In one of my posts I...
That approach is brutal! Damage to the board itself (eg lifted tracks) is the main risk when undertaking a job like this and readers are strongly advised to see my post #102 (and others thereabouts - I joined the thread at #67) for a more board-friendly solution. Nevertheless, congratulations...
Yes, although not quite as bad. I'm usually fanatical about removing flux residue from boards I work on but resisted the temptation this time as I wanted to minimise the work to the board in case I disturbed/damaged yet more things (I'd already blown-up a Mosfet). You didn't need to remove the...
Woody17 kindly sent me the duff 4u7 cap he removed from his PVR for me to check. As expected - replacing it did fix his PVR, after all - it is one sick puppy. I checked it with various instruments and initially found the results varied quite a bit, depending on the particular instrument, the...
The voltage rating isn't important - as long as it's more than 12V. 4u7 is quite a small value for an electrolytic capacitor so typical ratings are 25/35/50V (higher and they start getting physically bigger). Make sure you put in the replacement the right way round (check my pics) - and ignore...
Thanks to /df for his kind words. It’s nice to be able to give something back to the forum as I’ve kept a copy of BH’s Things Every HD/R-Fox T2 Owner Should Know to hand for many years now. I’ve never had to break the seal on our original PVR before but now it’s working again, and we have two...
Replacing the Mosfet (U24) and the 4u7 cap in the HDD 12V switching circuit has fixed our faulty PVR; it is an ex-faulty PVR. The conclusion, then, is that the likely culprit for any problem embraced by this thread’s title (or something similar, especially if temperature-related) is that...
Thought I’d check the newly-arrived Mosfets (FDC658AP) on my Peak Atlas DCA Pro/75 analyser. It correctly identified the type and the initial curve-tracing results are as expected. Reducing the Vds test range and increasing the Vgs test range would provide a better match to the figure in the...
Yep, that was it - many thanks. This doesn't appear to be a menu setting, just a dedicated button on the remote control (which is why I'd overlooked it). Sitting in the dentist's chair this afternoon I remembered that the other day I hadn't been able to select the aspect ratio "Just Scan" on...
If you’ve been following recent developments on this thread, you’ll know that I’m awaiting arrival of some Mosfets. Fitting a new Mosfet (to replace the one I blew up) and a replacement 4u7 cap (both in the HDD 12V switch, and the latter the likely cause of the problem captured in the title of...
Famously, these series-RC networks are usually to be found across audio power amplifier outputs (as a sort of power-factor correction for the inductive load presented by the speaker) to aid stability. I recall, as a lad, absorbing all the useful info in the little white booklet that came with...
Thought I'd check the other 4u7s in my spares drawer (at room temperature) - all the ESRs are well below 20R. See post #96 for the checks on the suspect cap, which strongly suggest it's seriously unwell.
[Edited 29 Nov 2021 to add following.]
When selecting a cap to fit as a replacement for...
Well done for sticking with it and getting the PVR going again; even if your soldering isn't, your tenacity is impressive! Might be worth applying a few strategically-placed blobs of Araldite for mechanical stability/to prevent possible shorts. Looks like the cap is the correct way round with...
Correct - the component immediately to the right of the 4u7 cap is the 10k resistor shown in parallel with it in the circuit diagram. I measured the three resistors of interest with a DMM when determining the circuit (see post #91). But beware! These are ant-sized components and can easily...
That looks horrible! Certainly a degree of skill and experience with a soldering iron is called for when replacing the cap - but plentiful tips on how to achieve a successful outcome are to be found in the many pages of this topic. New readers please note!
Excellent! Hearing stories like this one makes all those hours I spent nailing this one even more worthwhile. Well done for persevering; there's a lot to be said for the "what-the-hell" approach! As you found, it often pays dividends.
Another satisfied customer - congratulations!
The attached shows what's really going on with the HDD supplies (top: 12V; bottom: 5V) - in this case it all comes good after the dud cap has warmed up enough (HDD supplies switch off at end as this was a "mains-on" start).
In one of my posts I...
That approach is brutal! Damage to the board itself (eg lifted tracks) is the main risk when undertaking a job like this and readers are strongly advised to see my post #102 (and others thereabouts - I joined the thread at #67) for a more board-friendly solution. Nevertheless, congratulations...
Yes, although not quite as bad. I'm usually fanatical about removing flux residue from boards I work on but resisted the temptation this time as I wanted to minimise the work to the board in case I disturbed/damaged yet more things (I'd already blown-up a Mosfet). You didn't need to remove the...
Woody17 kindly sent me the duff 4u7 cap he removed from his PVR for me to check. As expected - replacing it did fix his PVR, after all - it is one sick puppy. I checked it with various instruments and initially found the results varied quite a bit, depending on the particular instrument, the...
The voltage rating isn't important - as long as it's more than 12V. 4u7 is quite a small value for an electrolytic capacitor so typical ratings are 25/35/50V (higher and they start getting physically bigger). Make sure you put in the replacement the right way round (check my pics) - and ignore...
Thanks to /df for his kind words. It’s nice to be able to give something back to the forum as I’ve kept a copy of BH’s Things Every HD/R-Fox T2 Owner Should Know to hand for many years now. I’ve never had to break the seal on our original PVR before but now it’s working again, and we have two...
Replacing the Mosfet (U24) and the 4u7 cap in the HDD 12V switching circuit has fixed our faulty PVR; it is an ex-faulty PVR. The conclusion, then, is that the likely culprit for any problem embraced by this thread’s title (or something similar, especially if temperature-related) is that...
Thought I’d check the newly-arrived Mosfets (FDC658AP) on my Peak Atlas DCA Pro/75 analyser. It correctly identified the type and the initial curve-tracing results are as expected. Reducing the Vds test range and increasing the Vgs test range would provide a better match to the figure in the...
Yep, that was it - many thanks. This doesn't appear to be a menu setting, just a dedicated button on the remote control (which is why I'd overlooked it). Sitting in the dentist's chair this afternoon I remembered that the other day I hadn't been able to select the aspect ratio "Just Scan" on...
If you’ve been following recent developments on this thread, you’ll know that I’m awaiting arrival of some Mosfets. Fitting a new Mosfet (to replace the one I blew up) and a replacement 4u7 cap (both in the HDD 12V switch, and the latter the likely cause of the problem captured in the title of...
Famously, these series-RC networks are usually to be found across audio power amplifier outputs (as a sort of power-factor correction for the inductive load presented by the speaker) to aid stability. I recall, as a lad, absorbing all the useful info in the little white booklet that came with...
Thought I'd check the other 4u7s in my spares drawer (at room temperature) - all the ESRs are well below 20R. See post #96 for the checks on the suspect cap, which strongly suggest it's seriously unwell.
[Edited 29 Nov 2021 to add following.]
When selecting a cap to fit as a replacement for...
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