Click here to go to the forum index Click here for the home page
 
Author Message

<  Bugs  ~  PSU Repair - Latest Information

Page 16 of 18
Goto page Previous  1, 2, 3 ... 15, 16, 17, 18  Next
andyfras
Posted: Sat Nov 22, 2014 8:30 am Reply with quote
Frequent contributor Joined: 25 Jul 2005 Posts: 3391
DavidBelgium wrote:

Mains voltage is 217 V, which is at the low side and voltage over the big cap is 303 V
I might need to play with the resistor value of R3 to change the voltage divider and to raise the voltage a tiny bit.

No, don't change any values.

Check the secondary diodes. If one is short-circuit, it can prevent the PSU from starting.

Otherwise, you could send it to me.

_________________
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
View user's profile Send private message Visit poster's website
MikB
Posted: Sat Nov 22, 2014 10:57 am Reply with quote
Frequent contributor Joined: 23 Sep 2006 Posts: 282 Location: West Midlands
DavidBelgium wrote:

Mains voltage is 217 V, which is at the low side


It's fine -- the Topfield power supply is quite tolerant of voltage variations. Maybe Andy has experimented on one and got a low-water mark for this Smile

Before I had mine on a UPS, there was an "incident" here where the mains voltage dropped enough to put the lights and some pieces of hardware into darkness, yet the Topfield carried on running. It was only like that a few seconds, before the power went out totally.

Very confusing: Can't be a power cut, Topfield is still on ... oh ... hang on. It's not anymore.

According to the PCs, the voltage sagged to around 90v and it kept going.

It didn't run at 0v.

_________________
Toppy Taps: http://toppy.signal11.org.uk

TF5800, IA On, TS On, F/W: 5.13.65T 14/4/2009 -AbCkEeEfEpHeKtRaRhRsSdStSyTeTfTpTsVr+Pf
TAPs: DescriptionExtender 2.1; MeiSearch 1.30; EPG Clean V1.01 Dev Version; EPGnavigator v5.1c; MyInfo B5.6;
Sig generated by MyInfo on 17/1/15
View user's profile Send private message Visit poster's website
andyfras
Posted: Sat Nov 22, 2014 2:58 pm Reply with quote
Frequent contributor Joined: 25 Jul 2005 Posts: 3391
MikB wrote:
Maybe Andy has experimented on one and got a low-water mark for this Smile

I've never tested the threshold, but the back plate of the Toppy says it will work between 90V and 250V.

_________________
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
View user's profile Send private message Visit poster's website
alan_m
Posted: Sat Nov 22, 2014 7:07 pm Reply with quote
Frequent contributor Joined: 18 Oct 2006 Posts: 3413
andyfras wrote:


Check the secondary diodes. If one is short-circuit, it can prevent the PSU from starting.



I've had a PSU where a short circuit diode (D5 - part = UF5404) in the transformer output circuits resulted in a dead Toppy. Repaired by replacing D5.

_________________

5800 - 1Tbyte HD and fan F/W: MS6, 5.13.65T 18 Nov 2010 -Te+B2D plus aXeL
Auto Start:MyStuff 6.5|EPG2MEI v0.96|Extend v1.7|SecCache (UK) v0.4|TF5000 Display v1.53|MHEG On/Off A3
View user's profile Send private message Visit poster's website
DavidBelgium
Posted: Sun Nov 23, 2014 12:29 pm Reply with quote
Joined: 15 Nov 2014 Posts: 9
All,

It's not entirely dead, it is alive but voltages are very low and too low to start even anything. When I attach my scopemeter, I see on cathode of D1 vs chassis every 175-200ms a 25V dc peak. So I presume the coil is energized at primary side

[/img]

Output voltage on 30v = approx 6.85v
Output voltage on 5v = approx 1.35v
So they are all approx 4 times to low
View user's profile Send private message
andyfras
Posted: Sun Nov 23, 2014 2:16 pm Reply with quote
Frequent contributor Joined: 25 Jul 2005 Posts: 3391
Check the rest of the voltages and that should show which diode is shorted.

_________________
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
View user's profile Send private message Visit poster's website
sinnottj
Posted: Sun Nov 30, 2014 2:14 pm Reply with quote
Joined: 01 Jul 2008 Posts: 5 Location: Macclesfield
Hi,

I'm looking for some advice, if anyone can help! I have a 5800 that is coming up to 6 years old and (so far) has been running OK. Once in a blue moon I get the odd glitch - a reboot, or a recording goes wrong - but months generally go by without any issue. However, I realise I'm probably living on borrowed time!

I actually bought a spare PSU (from Turbosat) a few years ago, after first reading about the failures on this forum, but it's been sitting in a drawer ever since. However, I'm wondering if the time has finally come to remove the old PSU and fit the replacement.

So, my question is this - is it worth getting the capacitors replaced on the new PSU before fitting it?

I've attached a few images of the new PSU, and if expert can give me an opinion, I'd be very grateful!



View user's profile Send private message
sinnottj
Posted: Tue Dec 02, 2014 11:03 pm Reply with quote
Joined: 01 Jul 2008 Posts: 5 Location: Macclesfield
Bump! Anyone able to offer me some advice?
View user's profile Send private message
ryclark
Posted: Tue Dec 02, 2014 11:24 pm Reply with quote
Frequent contributor Joined: 10 Jul 2005 Posts: 1611 Location: Shropshire
Well if the "new" PSU has been sitting in a draw unused then it's capacitors are unlikely to have deteriorated. So it is likely to last you quite a few years unmodified. If you change all the caps then it would quite likely last even longer. So are you likely to want to keep your Toppy going for longer than another five years? If you are then change the caps. Otherwise enjoy until you want something that receives HD. Very Happy

_________________
TF5800t, TS On, F/W: MS6 Recommended F/W 12/9/2009 -Fm
TAPs: PcControl B1.4; MyInfo B5.6; EPG2MEI v0.96; MyStuff 6.6; MHEG On/Off A3; Extend v1.7; SecCache (UK) v0.4; EIT Sub (Game) v0.6; TSSaver v0.5;
Sig generated by MyInfo on 13/10/14
View user's profile Send private message
fhjones
Posted: Tue Dec 02, 2014 11:44 pm Reply with quote
Frequent contributor Joined: 25 Feb 2009 Posts: 160
Why not put the new one in, replace the caps on the old one and keep it as a spare.

_________________
TF5800, F/W: MS6 Recommended F/W 12/9/2009 -FmSyXl+UUu
TAPs: PcControl B1.4; EPG2MEI v0.96; MyStuff 6.6; PruneEPG 1.0; MyInfo B5.6; SecCache (UK) v0.4; EIT Sub (Game) v0.6; MHEG On/Off A3;
Sig generated by MyInfo on 19/11/15
View user's profile Send private message
sinnottj
Posted: Wed Dec 03, 2014 10:23 am Reply with quote
Joined: 01 Jul 2008 Posts: 5 Location: Macclesfield
Thanks both for the replies.

I agree the lack of HD limits the shelf-life of my Toppy, but MyStuff still keeps me loyal. I periodically look at potential replacements, but nothing has convinced me to part with my cash yet ...

I guess I'll open it up and see how hard swapping the PSU over is going to be!
View user's profile Send private message
juwlz
Posted: Wed Dec 03, 2014 6:08 pm Reply with quote
MyStuff Team Joined: 12 Aug 2005 Posts: 10802 Location: Wokingham, Berkshire (Hannington transmitter)
fhjones wrote:
Why not put the new one in, replace the caps on the old one and keep it as a spare.
That would be my suggestion too. You could even send the old one to andyfras in Fleet, Hampshire, to repair for you. I'm guessing that if you're concerned about swapping the PSU, replacing the caps in the old one is probably a bit more advanced! Alternatively, if you do want to DIY, he sells a kit of Toppy-specific capacitors at VERY reasonable prices (better than minimum quantity quality online suppliers).

Julie

_________________
5800, TS On, F/W: MS6 Recommended F/W 12/9/2009 -Sy+BmC0CfCtFsIMPePsR3UUuUxZ
5810, TS On, F/W: F/W: MS6 Recommended F/W 12/9/2009 +BmCfCtFsR3Z
MyStuff info; Help!; Reference
Harmony 885 remote. Sig date 8 April 2012
View user's profile Send private message Visit poster's website
sinnottj
Posted: Wed Dec 03, 2014 8:24 pm Reply with quote
Joined: 01 Jul 2008 Posts: 5 Location: Macclesfield
juwlz wrote:
fhjones wrote:
Why not put the new one in, replace the caps on the old one and keep it as a spare.
That would be my suggestion too. You could even send the old one to andyfras in Fleet, Hampshire, to repair for you. I'm guessing that if you're concerned about swapping the PSU, replacing the caps in the old one is probably a bit more advanced! Alternatively, if you do want to DIY, he sells a kit of Toppy-specific capacitors at VERY reasonable prices (better than minimum quantity quality online suppliers).

Julie


Thanks for the advice!

I actually took the plunge a short while ago and swapped the PSU Very Happy Very simple to do and (so far) my beloved Toppy is not showing any ill effects ...

I might get in touch with andyfras, as you suggest, and see about upgrading caps on the old PSU (there's no way I'm up to doing that myself Shocked )

Out of interest does anyone know to what extent a Toppy PSU with failed capacitors represents a fire risk? Or would operational issues(e.g. HDD failure) manifest themselves before it got to that point?
View user's profile Send private message
Bizman
Posted: Wed Dec 03, 2014 8:33 pm Reply with quote
Frequent contributor Joined: 06 Apr 2010 Posts: 1700
sinnottj wrote:
Out of interest does anyone know to what extent a Toppy PSU with failed capacitors represents a fire risk? Or would operational issues(e.g. HDD failure) manifest themselves before it got to that point?
I imagine the fire risk is pretty low, but the risk of creating a more expensive repair is far more likely.

_________________
TF5810, F/W: 5.15.09T 4/9/2009 -FmTe+EzHsVb
TAPs: EIT Sub (Game) v0.6; SecCache (UK) v0.4; MHEG On/Off A3; MPDisplayLITE V1.2; MyInfo B5.6; PruneEPG 1.0; EPG2MEI v0.96; QuickJump 1.72; Extend v1.7; (fsSave 1.1);
Sig generated by MyInfo on 3/8/17

Other TAPs : FsCheck, Channel Organiser. PSU Caps 7/2/2011 Tx: Mendip. TV: Samsung (32"), NSLU2, STB: Labgear FV300. PC Acer Aspire One with Win7 Starter
View user's profile Send private message
sinnottj
Posted: Thu Dec 04, 2014 5:03 pm Reply with quote
Joined: 01 Jul 2008 Posts: 5 Location: Macclesfield
Yes, that's what I thought, thanks.
View user's profile Send private message

Display posts from previous:  

All times are GMT + 1 Hour
Page 16 of 18
Goto page Previous  1, 2, 3 ... 15, 16, 17, 18  Next

Jump to:  

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum