Hitachi 40HXC06U problems

[StephenU]

Hi Everyone,

I am currently working on a Hitachi 40HXC06U.

17IPS19-4 Vestel PSU fitted.

On initial power on the tv was stuck in standby, I went round all the caps and diodes, they all seemed fine I checked online and you can get a kit for this common problem,
(http://www.ebay.co.uk/itm/VESTEL-17I...4AAOSwX~dWrVev)
I had spare diodes of the same value so I replaced them all out with new ones, checked over all soldering, polarities etc etc. Put back together turned on and after a couple of seconds POP,
so out with the PSU to investigate, checks the rear of the board and IC201 (SG6742HR) had been destroyed along with R272 on the front of the board (0R47 WIREWOUND I BELIEVE??) (Also the little plastic cap type fuse was fine).
So ordered replacements of IC201 and R272 fitted checked was all ok, plugged it in, switched on at wall an BANG that little cap fuse blue completely off the board.
Could this be down to the resitror I fitted? Link to resistor that i replaced the damaged one - http://www.ebay.co.uk/itm/2915066576...%3AMEBIDX%3AIT

I will attached the schematics i have of the PSU, any pointers or help would be greatly appreciated. Thanks

Stephen

[ReeceyBurger123]

Re: Hitachi 40HXC06U problems

Yes, common issue with all Vestel supplies is the ceramic cap thats for vcc decoupling for the controller for the transistor shorting. Some times it will cause the set to be stuck in standby or it will cause it to blow. In all honesty it might be easier just to replace it these are dirt cheap on ebay. If not will help you diagnose the fucker lol

[StephenU]

Re: Hitachi 40HXC06U problems

Yes, common issue with all Vestel supplies is the ceramic cap thats for vcc decoupling for the controller for the transistor shorting. Some times it will cause the set to be stuck in standby or it will cause it to blow. In all honesty it might be easier just to replace it these are dirt cheap on ebay. If not will help you diagnose the fucker lol

Cheers Reeceyburger, we all enjoy the challenge rather than a board swap out. But lets see what happens.

Thanks for the reply.

Stephen

[StephenU]

Re: Hitachi 40HXC06U problems

Hi guys, is this a ceramic coated resistor or a wire wound?, I ordered a wirewound but now doubting myself. Value and reference R272 (0R47)

[dick_barton]

Re: Hitachi 40HXC06U problems

Prefix is R on the board so I would say resistor.

[StephenU]

Re: Hitachi 40HXC06U problems

Prefix is R on the board so I would say resistor.

That is correct, although my my question is - What type of Resistor is it?

Thanks for your reply dick_b


Stephen

[vinceroger69]

Re: Hitachi 40HXC06U problems

looking at some google images i would say its a wirewound

[StephenU]

Re: Hitachi 40HXC06U problems

looking at some google images i would say its a wirewound

Thanks Vince, would this be ok as an alternative -

http://www.ebay.co.uk/itm/3-Watt-Wir...QAAOxyRNJSb4F7


Stephen

[vinceroger69]

Re: Hitachi 40HXC06U problems

that links not working but i use rs components free next day delivery no minimum order or postage costs
http://uk.rs-online.com/web/home.html

[StephenU]

Re: Hitachi 40HXC06U problems

Could anyone else confirm if this is the correct part please.

Link seems fine to me, but item number for eBay: 291506657682

Thanks in advance.


Stephen

[StephenU]

Re: Hitachi 40HXC06U problems

that links not working but i use rs components free next day delivery no minimum order or postage costs
http://uk.rs-online.com/web/home.html

Thanks

[dick_barton]

Re: Hitachi 40HXC06U problems

Thanks Vince, would this be ok as an alternative -

http://www.ebay.co.uk/itm/3-Watt-Wir...QAAOxyRNJSb4F7


Stephen

Just check its size given and compare to yours so that it fits into the board.

[vinceroger69]

Re: Hitachi 40HXC06U problems

is that a original picture post 4 of the resistor you need? i wonder if its a fusible type etc as it has a lot of markings on it.

[StephenU]

Re: Hitachi 40HXC06U problems

is that a original picture post 4 of the resistor you need? i wonder if its a fusible type etc as it has a lot of markings on it.

That is correct Vince, although mines is in bits.

Thanks

[vinceroger69]

Re: Hitachi 40HXC06U problems

i wonder if budm has a idea what type of resitor that is?

[StephenU]

Re: Hitachi 40HXC06U problems

Had another look while awaiting parts coming, the old one that went one my baord had the markings 0.33 Ohm 1WJ (So Different value from Schematics...) - So the question is would this 3W 0.47 Ohm resistor be ok as a replacement, or will I be best going for the 1W version.

Thanks in advance for any advice / help on this board guys, its greatly appreciated.

Stephen

[dick_barton]

Re: Hitachi 40HXC06U problems

I wold stick with the original of 0.33 ohms 1 watt.

[vinceroger69]

Re: Hitachi 40HXC06U problems

As above post use a 0.33 ohms 1 watt if that is what was fitted originally.

[budm]

Re: Hitachi 40HXC06U problems

BTW, MOSFET Q204 is fine not shorted between Source and Drain?
C205 is the one that blew?

[ReeceyBurger123]

Re: Hitachi 40HXC06U problems

The mosfet probably is short, them resistors normally only blow on Vestels if the mosfet does which blows the controller as well.