Bauer XT32 / Phihong PSU fault

[ProDave]

I've got a Bauer XT32 which is a bit of an obscure set as far as I can tell.

It's PSU is completely blown.  The PSU is a Phihong switching power supply model PSM210-417

Does anyone have any information, circuit diagrams etc either for this PSU or the whole set?

[sparky]

hi
charles hyde do a kit also ohmsuppies
dave

[ProDave]

hi
charles hyde do a kit also ohmsuppies
dave

Thanks, I just found that myself.  I think Ohm supplies originate the kit and CHS just sell it (as CHS are more expensive.

I'm a bit reluctant to buy the kit as I don't know the state of this tv (i.e is the screen any good etc) so I'm looking to try and power up the tv to test the rest of it first.

Since this PSU outputs 5V, 12V and 24V, i'm tempted to rig up 3 bench power supplies to try and power up the set to see if it works okay before spending the money on the PSU repair kit.  Anyone ever tried anything like that?

I've also done some more research.  It seems these PSU's are unreliable and there's a lot of people with failures.  On mine the 5V standby IC has obviously blown (i's missing a leg) but the whole primary is shot (it just blows input fuses) hence I would need the full kit.

But what's puzzling me, is there are large splat marks on the chassis when you remove the PSU, but not much corresponding damage on the PSU.  To me it looks like there has been a flashover from the PSU to the chassis, rather than a PSU component blowing and causing the splat marks.

Could it be insufficient clearance between the PSU and chassis is the root of the unreliability of these? a sheet of mica insulation glued to the chassis, or longer spacers perhaps?

[Turnip]

Hi Pd,

The 5v S/by FSD200 is the usual problem - see Profilo Telra. Occasionally replacement of all the burned bits in the basic kit does the job. Failing that you are in some problem, as you can replace all the bits in the comprehensive kit and it still might not go - guess how I know ?

Fortunately this PS is also used in a certain cheapo plasma for low voltage supplies only where it has a quiet life - mended some XT32s from this source.

Confess that both my house tellies are XT32s, and the wife won't have my nice newly mended LG 42" plasma even though 'Corrie' and 'Emmy' would look bigger, and for me 'Dave', for a smile after the day's mending would be just the biz - Shucks - Chris.

Never win, ever  - Chris

[ProDave]

When I get time I'll have another look and see.  All I know for certain is the 5V stby reg has blown one of it's legs off, and the mains input fuse blows straight away.  From that I assumed the whole primary was U/S so was intending to buy the full kit, but could a blown 5V stby reg explain blowing the mains input fuse?   I'll remove the main heatsink later and have a look for more blown up parts.

What make and model set uses the same PSU? I'll keep my eyes open. If you don't want to tell everybody, send me a PM.

As you seem to know a lot about this set, I don't suppose you know a working Sky remote control setup code to allow a sky remote to operate this set?  I haven't found one listed anywhere yet.

As I say, before I spend much money on this I want to try powering it up from a set of bench PSU's to make sure the rest of the set, and the screen is okay.

I'm interested in you keeping and using two XT32's.  Have you done anything to improve the reliability?  I have bought this one as faulty, but having found out how unreliable this PSU is, I would be very concerned about keeping it to use unless there was something that could be done to improve the reliability, so if I do get it going it will probably be off to ebay.

[Turnip]

Hi Pd,

First met the prob with Profilo tellies, where FSD200 blows a leg and some nearby zeners and BC337, so thought to include a 4R7 (S) in the S/by HT feed should it pop again before repair guarantee had expired.

Sky codes for volume haven't been a prob as wife uses 5 hopeful RCUs for Freeview and Freesat even while washing up.

For reliability, just that 4R7, as there are no other reported problems if recovered with the initial FSD200 bits - if not -

Dave will be bigger with an LG Plasma  - Chris.

[ProDave]

Okay, making some progress.

I've powered up the tv from bench power supplies.  That took longer than it should as I found one output on my twin o/p bench PSU had died, so first job was to repair the bench PSU.

Anyway, fed with 5V, 12V and 24V from bench psu's the set works and has a good screen.  So at least I now know it's worth spending money to fix the PSU.

So I'll dismantle and look at the PSU probably tomorrow now.

[michael first]

Hi,ProDave take a look at this.As for the main fuse the cause could be one of the two SPP07N60(mosfet) along with the corresponding ICE1QS01.Hope it helps. 

[ProDave]

Here's what I found.  The cause of the blowing main fuse was a short circuit main reservoir capacitor.  No other obvious blown parts.

So I put the PSU back together and tried powering it up, with the 5V standby supply coming from my bench power supply.  But the rest of the PSU remains dead and the other voltages won't come on.

I'm reluctant to spend much time or money on this PSU, partly because it's a pig of a thing to work on, you have to remove a heatsink and 2 devices (attached to the heatsink) to get to most of the board, with no opportunity to do testing and fault finding. Plus of course there's no guarantee of success.

So I'm in the process of engineering an alternative power supply.  Here's what I am doing:

In my accumulation of bits, I had a small Lascar 5V linear psu.  This is now providing the 5V standby supply.  I also had a Melcher switching regulator that has a 12V output and 20-80V dc input range, so that is providing the 12V power.

The only bit I didn't have is a 24V psu.  So I've ordered one from someone on ebay for the princely sum of £16.35

All I need to engineer is some switching (a relay) to power up the 24V psu when the set is turned on and it should all work. (it's currently working with just the 24V supplied from my bench power supply)

This will have the advantage of being cheaper and more certain than any other fix, plus, in theory, it will all be powered with industrial power supply units, rather than a consumer quality PSU so will hopefully be more reliable.

It will sure confuse the next engineer that looks inside the set though.

To all those who know this set, do any of you have a users manual for it?  In particular does the hdmi input support HDCP?  I'm confused by the labelling on the back of the set referring to it as a DVI input which rather suggests it does not fully implement hdmi and hdcp.

[Turnip]

Hi Mike 1st.

Sorry now I mentioned Profilo, it was just that FSD200 pop business, where repairing the original problem sometimes gives a solution, but often - not.

Never dismayed, as local tips are now full of 'em - Chris.

PS - as a thought, RM4040 from Wiltsgrove usually does the biz for Profilo stuff, for XT32 it's IRM1165.

PPS - Hi, Pro Dave, just grateful it does the basic biz - wife happy with Corrie and Emmie, so won't try open any of Pandora's boxes, as tea might be in doubt.

[ProDave]

I'm still waiting for my PSU (ordered from ebay from Hong Kong).  In the mean time I've been testing the set, still on the bench psu.

Two problems found:

Scart input will only work on PAL. If I switch the sky box to RGB, the screen blanks and the sound mutes, though the status box pops up on the tv screen to announce "RGB SCART" So it's detecting RGB, just not displaying it.

The hdmi input won't display a picture from the sky box, I've tried all the different output resolutions on the sky box, but no picture on the tv. The status box says "hdmi 0 Hz" rather suggesting it can't see any signal.  I know the sky box is okay, it's hdmi output works on another tv.

The component Y Pb Pr input works fine, and displays a stunning HD picture.

Anyone got any ideas about these non working inputs?

And does anyone know how to get into service mode on this tv?  I'm sure I saw it somewhere, press menu then 4 digits, but I can't find it again.

Thanks.

[ProDave]

Here's the finished "project"

The 24V PSU has arrived, it only took a week from Hong Kong.

So if you look at the photo, the silver perforated box is the new 24V PSU. To the right of that the black box with red writing is the 12V switching regulator, and further right still, the grey box is the little linear PSU to provide the 5V standby.

The orange thing to the left of the 24V PSU is the relay that turns the main PSU's on when the set turns on. If you think it looks a bit large, the first one welded it's contacts after 3 operations, so I've fitted a large one and also a contact suppressor this time.

And if you look carefully at the stand, you will see it's from a different set with different mountings, so 2 bits of steel bar bolted on to extend that bracket to mate with the fixing screws for the original stand.

You can still see the splat marks on the chassis where the orignal PSU blew up.

[tv tony]

excellently engineered but its hardly a green tv now is it, must say though it requires great thought and a touch of madness to achieve such a thing, takes me back to when i used to mod sony kv1810,s to take line transistors and modified a sony kv2000mk11 to take a g11 psu, happy days
tony walker

[ProDave]

I'm not sure I understand the bit about this mod not being "green"?

Are you referring to the power consumption?  If so, this set now draws 0.5A @ 240V when running, which gives a power consumption of 120W.  The rating plate on the back of the tv says 120W also, so it looks like my cobbled together PSU is just as efficient as the original one.

I think this is very green. The alternative was a set that was probably uneconomic to repair, so would have ended up as scrap.

This is not my first unusual mod to a tv.  I've done one or 2 other unusual things, starting many years ago when I fitted a solid state tuner module from a scrap tv into a valve set.  I had to fit a couple of dropper resisters to complete the heater chain in place of the 2 valves in the original tuner, and cobble together a 12V supply for the solid state tuner.  But it worked like that for years.

Incidently, I've done some more work on this set today.  Once I put it into use in my living room, it very soon became clear the sound from this set was very poor.  Both in terms of lack of bass, and annoying vibrations at certain frequencies.

This was solved by fitting a different pair of speakers from a scrap crown set, which thankfully were the same physical size, and the vibrations were tracked down to parts of the chassis that were vibrating together at certain frequencies, cured by securing the loose parts with aluminium tape.

I know this was a budget tv, but how the designers could let it into production with such poor sound astounds me, particularly given how easy it was to improve.

[halen]

Hello

I have Telra@ PT1000 chassis, same with attach in this thread and I have problem. I played with service menu (what mystake) and set bad LCD display type. This is in menu Option / LCD. I have LG 32" and set wrong display. Please is there some way to restore it? Now TV dont display anything, only audio works. TV remote and buttons on TV doesnt work too. Please help me.