Topfield PVR Faults

 Unreliable operation, 5800
 PSU Capacitors
 The main 6 x 1000μF @ 16V + 12 others that have been known to fail.
 Brown Sam Young caps on early models were replaced with slightly better quality black SamXon in later versions.
 Green SamXon C22 & C25 often dome when failing.
 Unreliable operation, 5810
 PSU Capacitors13 capacitors - 1000μF @ 10V, 680μF @ 25V, 2 x 1500μF @ 10V, 5 x 330μF @ 25V, 3 x 33μF @ 50V, 1μF @ 50V
Green Samxon capacitors often show 'doming' when failing.
 Rebooting U20 regulator m'board
 Tab should measure 1.5V, if not, replace with LD1117DT (left side of cardslot)
 No Tuning
 Q14 mainboard
 Replace with SM transistor MMBT4403 - labelled 2T
 No Tuning
 No 30V from PSU
 Replace R5, D3 and C10 (D3 gone leaky which blows R5 and damages C10)
 HDD not running
 U51 mainboard
 Replace with SI9936 dual FET switch (next to HDD power connector on mainboard)
 This can be caused by short-circuit voltage protection diode on HDD (check first)
 Sometimes Q22 is also blown MMBT4401 - labelled 2X
 Not booting
 U22 regulator m'board
 12V regulator LM78L12 (3cm behind scart sockets)
 No Clock Display
 Q13 mainboard
 Replace with SM transistor MMBT4401 - labelled 2X (next to front panel connector)
 Dead - PSU heatsink hot
 D1 PSU  (5800) Replace with 1N4937 (between large heatsink and transformer)
 Dead - PSU heatsink hot D4 PSU (24V) (5800) Replace with UF5404 or equivalent 3A fast recovery diode - (also changed C12)
 Dead - PSU heatsink hot D11 PSU (3.3V) (5800) Replace with DSA10I100 Schottky diode mounted on heatsink (Farnell 1572488)
 Dead - PSU heatsink hot D8 PSU (12V) (5800) Blown along with U51 due to short-circuit HDD over-voltage protection diode
 Suitable replacement - STTH802FP (Farnell 1697526)
 Dead - PSU heatsink hot HDD VP Diode If U51 or D8 do not fail, the 12V rail is shorted and will load the PSU
 Dead - PSU heatsink cold V1 (1M0680R) (5800)
 If voltage across R3 is less than 15V, V1 may have failed - Up to 400V on heatsink!
 Dead - PSU heatsink cold R1 (150kΩ) (5800) Power to switching IC - also discharges C5 (150μF 400V) when mains is removed
 Dead - PSU heatsink cold C5 (0.01μF) 5810
 Capacitor had gone leaky. PSU would not start unless meter probe touched on C4 case
 Dead - accidental short
(often while replacing HDD)
 Fuse + Bridge Rectifier
 5800 - 2AT 20mm ceramic fuse + 2A x 600V bridge
 5810 - 3.15A Fuse (PCB mount) + RL207 diode (check which one is s/c)
 No syncs on RGB or CVBS
 Q26 mainboard Replace with SM transistor MMBT4403 - labelled 2T
 Remote intermittent, 5800
 Front Panel IR Receiver
 Replace with Vishay TSOP34836 or similar 36kHz photodiode
 No USB connection
 U54 mainboard
 Replace with NET2270 - impossible without specialist equipment (which I have)
 Clock wrong in s/by 5810
 Front Panel battery
 2032 battery, requires removal of front panel PCB - 5800 does NOT have a battery

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