"Tony" wrote in message
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ian field wrote:
"Tony" wrote in message
...
ian field wrote:
"Tony" wrote in message
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ian field wrote:
Having turned out not to have been affected by the end of InView EPG
service - my FVRT90 promptly died.

When I went to use it the power LED came on and then it froze, so I
unplugged it for 30 seconds and plugged it back in, whereupon the 7
segment display run through the Klingon alphabet and then went blank.

Hopefully it only needs a PSU recap or dry joints sorting out -
otherwise I'll have to put up with the less than favourite Techwood
(Vestel) and the POS Nikkai barebones.
Does it do that every time you cold boot it now?

Could be the flash is worn out or the drive is knackered. I think the
test pattern comes up when there are channels stored but the drive is
not formatted (ie it thinks its in the factory). I'm not entirely
sure.
A full PSU recap fixed it - its my favourite PVR so I beefed up the
main smoothing electrolytics with 10uF multilayer ceramic chip
capacitors on the print side.

There's also a 1uF electrolytic in the regulation circuit on the
primary side, if this fails the PSU can go bang - it wasn't hard to
find a non-electrolytic 1uF that will never dry out.

The mains rectifier reservoir capacitor was a flimsy ordinary type with
lead wires instead of riveted tags like this component should have - I
drilled new holes and fitted a propper one.

All of the electrolytics (except the 3 directly on the cathodes of the
3 rectifiers) looked cheap & nasty - the ESR readings didn't look all
that bad, but evidently too high for the PSU to work correctly.
Cool, useful to know when mine goes. Perhaps the 12v for the drive went
down. Did you find the faulty location(s)?

The PSU was working (sort of) but the voltages were all high except the
3.3V and it probably had too much HF ripple upsetting the logic board.

I was lucky the overal deterioration of the electrolytics caused symptoms
I couldn't ignore.

There's a couple of small electrolytics on the primary side that can
cause gradual regulation failure as the ESR increases - capacitors with
high ESR get a degree of self heating from the ripple current, if allowed
to cool the ESR increases a lot with the result that the PSU can go bang
if the mains goes off for a while and comes back on.

One of these critical electrolytics is only 1uF - not hard to find a
non-electrolytic replacement small enough to fit.

If your's is anywhere near 10 years or more old, I'd reccomend a recap
before it does go bang. Use the best high temp - low ESR electrolytics
you can get hold of.

I got 10uF multilayer ceramic chip capacitors to pad the 6 secondary side
smoothers from a scrap LCD TV, but you should be able to order similar
from the likes of Farnell.

I may have been involved in its manufacture. Does it have an 'N' in the
serial number?

Didn't look and its wedged in the AV stack with me watching TV its decoding.


The PSU was bought in assembled from a reputable manufacturer but we
didn't control the AVL for the parts in it. I am very particular about
electrolitics.


Something I should have made a note of is the part number of the TOPswitch
chip - if at any time the PSU blows, the chip usually shatters making the
number unreadable.

Although I did add a ZNR varistor to the mains connector while I had the PSU
board out - its a bit OTT really, the PVR is fed by a UPS with built in
supression and that is distributed to the AV stack by a socket strip which
also has surge supression.

You'll need to be quite a bit particular about your electrolytics to find
better than the 3x 220uF/35V smoothers directly on the rectifier cathodes -
they were pretty good even after 10 years - all the other electrolytics
should be replaced with top quality low ESR types.