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<  OZ Toppies  ~  TF5000PVRt Masterpiece - No Power to Hard Drive

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Nasho23
Posted: Mon Feb 09, 2015 11:54 am Reply with quote
Joined: 09 Feb 2015 Posts: 2 Location: Australia
After having been in service and functioning as a backup machine for quite some time now, this unit was found to be dead (nothing on front screen) switched on or off, when I needed to use it a few days ago. I first suspected Capacitors on Power Board (ORTP-831 Rev 5). I replaced C17, C18, C19, C22, C23, & C25. Result was, I now had info on front screen and standby switch worked as it should, however no power at the HD Molex Plug to spin up the HD. Checked the Voltages at the Power Board Cable blocks and all are in spec, as per a Voltage List I found on WikiBooks.
So it appears that there is a problem on the Main Board that is preventing power to go to the HD. Cannot see anything obvious.
Has anyone had experience similar to this and can someone provide advice on repair.
Cannot seem to find a Toppy Repairer around Melbourne area in Australia.
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alan_m
Posted: Mon Feb 09, 2015 2:01 pm Reply with quote
Frequent contributor Joined: 18 Oct 2006 Posts: 3523
Nasho23 wrote:
So it appears that there is a problem on the Main Board that is preventing power to go to the HD. Cannot see anything obvious.
Has anyone had experience similar to this and can someone provide advice on repair.
Cannot seem to find a Toppy Repairer around Melbourne area in Australia.



The recommendation is to replace up to 18 capacitors on a 5xxx PSU

Common Toppy faults
https://sites.google.com/site/andyfraserelectronics/freeview-and-satellite-recorder-repair/topfield-pvr-faults

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Ex Toppy 5800 user - now migrated to Extrend ET10000 Enigma 2 box with 2 terrestrial and 2 satellite tuners
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andyfras
Posted: Mon Feb 09, 2015 5:38 pm Reply with quote
Frequent contributor Joined: 25 Jul 2005 Posts: 3468
Almost certain that U51 on the mainboard has failed. This will have been caused a by a diode on the HDD going short-circuit to protect the disk from excessive voltages from the failing PSU.

U51 is an 8 pin surface mount device near where the HDD power comes from the mainboard. There will often be physical signs of failure (crater).

The short-circuit diode on the disk can be removed and the disk will probably be OK. Ideally, the diode should be replaced to protect the disk from future voltage excesses. Do NOT connect the disk to anything until the diode has been removed/replaced, as there is a strong chance that it will cause further damage.

As alan_m has mentioned, you need to replace more capacitors too.

I have repaired Australian Toppies. The postage is not too expensive on small items (i.e. NOT the complete Toppy), but it will be several days in transit.

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Toppy PSU repair service or capacitor kits for DIY available - PM me for details.
MyStuff 6.6 : Little Clock : MHEGOnOff : Extend : EPG2MEI : SecCache : EIT_Sub : TSSaver : Prune EPG
Channel Organiser : Tap Commander : HDD Info : PCControl : Signal Monitor : MyInfo
URC-7555 remote: TF5800 320GB 2.5", Recommended_5800.tfd + CfPePsScUUuWfZ
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Nasho23
Posted: Tue Feb 10, 2015 12:09 am Reply with quote
Joined: 09 Feb 2015 Posts: 2 Location: Australia
Quote:

Thank you both for your contribution to my issue.
I have examined U51 with a magnifying glass and there appears to be a blister on it, suggesting it may be kaput. Jaycar Aust do not have S19936 Surface Mount FET.

I have examined my HDD (Seagate 160Gb "U" Series 9 - ST3160022ACE) and cannot see a Diode that I am familiar with. Is there a picture and/or location for this Diode.

In respect of the board, I will need to find an electronics repair shop near home, as my 80 year old eyes are no longer good enough for this work, to say nothing about my shaky hands.
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andyfras
Posted: Tue Feb 10, 2015 2:24 pm Reply with quote
Frequent contributor Joined: 25 Jul 2005 Posts: 3468
The S19936 is very hard to come by, but there are several alternatives. I have used IRF7303 and IRF7311, but any MOSFET, DUAL, NN, LOGIC, SO-8 device with at least 4A and 20Vdss capability should be OK. If you're stuck, I can send you one.

The protection diode on the disk will be connected to the 12V pin on the 4 way Molex connector (the pin nearest the edge of the disk) It's black and about 4mm x 3mm. Suitable replacement is SMAJ12A.

Jaycar Aus stock this one (Si4944DY):

http://www.jaycar.com.au/productView.asp?ID=ZK8821

_________________
Toppy PSU repair service or capacitor kits for DIY available - PM me for details.
MyStuff 6.6 : Little Clock : MHEGOnOff : Extend : EPG2MEI : SecCache : EIT_Sub : TSSaver : Prune EPG
Channel Organiser : Tap Commander : HDD Info : PCControl : Signal Monitor : MyInfo
URC-7555 remote: TF5800 320GB 2.5", Recommended_5800.tfd + CfPePsScUUuWfZ
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