[mutenvo]

Hi
I bought a 26" Hitachi LCD tv 2 years ago.
This week the tv has started failling when I switch it on.
Basically, the image gets sometimes splitted in a few parts (always horizontally), some parts gets frozen, sometimes are zoomed, even the display menus are shown wrongly.
Then, after 5 minutes it starts working fine. It seems it needs to warm up.
I think it is a matter of the LCD Screen, as the OSD is also affected. And I've got the same problem even disconnecting all the input cables (antenna, pc, etc).
Any help?
Thanks!

[JayCee]

Originally Posted by mutenvo

Then, after 5 minutes it starts working fine. It seems it needs to warm up.
I think it is a matter of the LCD Screen, as the OSD is also affected

Faults that clear after a warmup period are almost always caused by faulty capacitors in the power supply section.
It's unlikely to be the screen.

[mutenvo]

Originally Posted by JayCee

Faults that clear after a warmup period are almost always caused by faulty capacitors in the power supply section.
It's unlikely to be the screen.

Do you think it can be fixed easyly? I have done some DIY with computers, but never tried with tv..

Thanks

[JayCee]

If you can solder neatly and are comfortable handling electronic components you should manage it.
If you decide to tackle it, once you have the back off the set identify the power supply circuit board and look for domed top or swollen electrolytic capacitors...if in doubt post a pic here of the power pcb.

[mutenvo]

Hi
I've dismounted the power board. I don't see anything wrong.
Could you please have a look?

[JayCee]

What's the TVs model no?

[mutenvo]

Hitachi 26LD4550U.
I've just gone to Maplin and bought a few capacitors. I will try to replace and test them one by one.
Any idea which one to start for?

[JayCee]

Can you report back with the PSU pcb no "17PW??"
It should be printed on the board somewhere.

[mutenvo]

Originally Posted by JayCee

Can you report back with the PSU pcb no "17PW??"
It should be printed on the board somewhere.

I suppose is this:

In PCB review:
715T3271-1

[JayCee]

Nothing beginning with 17PW anywhere?
It's usually printed on the board...not on a label stuck onto the board

[mutenvo]

Nothing. I cannot see 17PW in any of its sides.. ?

[JayCee]

If there's no "17PW??" that means the set is not a Vestel-manufactured set which most Hitachi TVs are/were.
A blanket replacement of the electrolytic caps on the pcb certainly might get results but most repair technicians would probably use a piece of testgear called an "ESR" meter which can test a cap in-circuit and reveal faulty and/or failing caps quickly.
To speed up your fault-finding you can use a technique the trade uses a lot and that is to direct warm air from a hairdryer to suspect caps and then switch on and see if the fault symptoms have cleared or clear quicker.
Obviously there are dangerous voltages around the psu pcb so be extremely careful.
Good luck.

[mutenvo]

Hi JayCee
Thanks for your help.
I think I've understood what you suggest.
1 - Let the board cool off.
2 - Heat up with the hairdrayer one capacitor.
3 - Switch the tv on.
4 - Check whether the image is still faulty.
4.1- If it is faulty, try another capacitor.
4.2 - If it fine, replace the capacitor.

Am I right?

Thanks a lot.

[JayCee]

Yes, that's the idea.
Just "play" the heat on one or two caps for about 20 secs then switch on, if the image is good and the fault is gone or the symptoms greatly reduced you've found the faulty cap.

[mutenvo]

Thank you, I will do it tomorrow morning when the tv is cold. I will let you know.

[mutenvo]

Good news, the tv is fixed

Total cost £12 (solding iron + stannel + a few capacitors). Real cost: < £1 (two capacitors -maybe only one-, if you already have solding iron).

The trick of the hairdryer worked perfectlly. I owe you a drink

Thanks.

[JayCee]

Glad to hear you managed it
Don't suppose you know the circuit ref no of the faulty caps for future use?...or can you identify them in the pic of the psu board?

[Emrysc]

Can you plese indicate on the picture of the board the capacitors that you changed?
Thanks

[mutenvo]

Hi
I replaced the three capacitors on the top left of the picture.
It worked for less than one week

Then I changed all of them, but the big one. I think there might be something else.

So that I've ordered the full board to the manufacturer, it costs over £60. Still waiting for it.

If it doesn't fix the problem, I will have to buy a new one, this time I'll make sure to extend the warranty, as I've read it is a common problem in many LCD TV such as Samsung, Sony, Hitachi...

[Emrysc]

I did the heating up trick and on heating 470uF 35V capacitor on the top left the TV started up normally.I will check it again tomorrow to confirm that this is the one that is giving the problem.Then I will replace it.I will let you know how I get on.
PS i have already purchased a new LG set and I hope that this does not suffer from the same problem- I did not buy extended warranty!

[Emrysc]

I changed 2 caps and the set worked fine for 6 days.then it played up again for 1 day and since has been fine.How did changing the PSU board work?

[mutenvo]

I ordered it on 9th March.. Still waiting.
Comet customer services is rubbish.
I will call them tomorrow, if they don't give me any concrete date, I will cancel it and buy a new TV.

[Emrysc]

Hi,I contacted hitachi about spares for this model and have been told that this is a Comet special brought in direct from hitachi and therefore hitachi europe do not want to know.the only place to get spares is comet.Seems that if we buy comet specials we definitely need to buy their insurance too! This makes the sets quite expensive.Did you finally manage to get the spare and did it solve the problem?

[mutenvo]

Hi
They told me it would take 28 working days.. I waited 32.
I called them again and they told me they had already chased the manufacturer for the board.. and I was told to wait another 28 working days. I cancelled the order.
I think they just wanted to make fool of me.
I've bought a Panasonic Viera 32".
Of Course, I will never buy anything neither in Laskys.com nor Comet.
I am going to sell the Hitachi tv as spare parts, and see if I can get something from it.
Good luck