Mulja tv repair portal

Equipment Repairs => LCD TV forum => Topic started by: ProDave on August 09, 2010,15:42:01

Title: Swisstec EJ20 stuck in standby (possibly AOC / Yusmart)
Post by: ProDave on August 09, 2010,15:42:01
I have a Swisstec 20" LCD television model Sky-EJ20/w/CG

Fault is stuck in standby.

Googling suggests it's made by Yusmart, here it is: http://www.skwd.sk/yusmart/products6.htm and it's also quite probably sold under the AOC brand.

Numbers on the main board are: N2010E JC206H63E  2202519 400 Rev 1.00

Any help or pointers please?

The PSU appears to output two 12V rails which are both okay.  There's also a clearly identifiable +5V derived from that on the main board that tests okay.

Standby light is illuminated yellow, but does not change colour when trying to turn the set on, nothing happens at all.

I don't have any service information at all.
Title: Re: Swisstec EJ20 stuck in standby (possibly AOC / Yusmart)
Post by: Turnip on August 10, 2010,11:05:30
Hi Pro Dave,

In the event of nothing better forthcoming, a piccy would be useful as we might know and curse it as something else.

All the best - Chris.
Title: Re: Swisstec EJ20 stuck in standby (possibly AOC / Yusmart)
Post by: ProDave on August 10, 2010,12:01:01
Good idea. Picture atached.

One thing I did try was removing the eeprom, and without the eeprpm plugged in you don't even get a standby light. With the eeprom in, the standby light comes on about a second after you plug the power in, so that looks to me like the processor is operating.

I have identified 12V  8V and 5V power rails all working, but haven't located a 3.3V rail, but being an old set it might not use any 3.3V?
Title: Re: Swisstec EJ20 stuck in standby (possibly AOC / Yusmart)
Post by: Turnip on August 10, 2010,12:12:01
Hi PD,

After that build up, and with cool voltages, guess we're all gagging for a piccy.  - Chris.

PS - see you've just added a piccy, looks cool, esp power, capwise, haven't seen it before, suspect prob might be in EEPROM area but have no info - thanks for piccy - building a file - Chris.
Title: Re: Swisstec EJ20 stuck in standby (possibly AOC / Yusmart)
Post by: EVILMRB on August 16, 2010,04:31:13
Hi swisstec are made by this company http://www.skymediauk.co.uk/
Title: Re: Swisstec EJ20 stuck in standby (possibly AOC / Yusmart)
Post by: Turnip on August 16, 2010,12:27:09
Hi Evilmrb,

Note they don't offer service info, just thoughts for folks who have trouble pushing buttons and still seek  cash for new crap.

In the old days, the (British) factory sent a technician - FOC to sort initial problems (sets lasted at least 20 years) or 'till woodworm got them.

Admittedly in those days (50's) TV sets were total crap but we earned up to £7.00 per week, making us high flyers, laughing at electricians, plumbers, and lino layers.   Times change  - Chris

Anyone with a dime or a double 22 to 14 coupler   ?
Title: Re: Swisstec EJ20 stuck in standby (possibly AOC / Yusmart)
Post by: EVILMRB on August 17, 2010,17:11:32
Hi turnip,

I got in contact with them  today over this UMC LCD i have,but would not give me any info just said if i sent the set could be any thing from £49-£150..wouldn`t mind but the set only retails for £149.99 in Tescos.. :41:
Title: Re: Swisstec EJ20 stuck in standby (possibly AOC / Yusmart)
Post by: ProDave on August 23, 2010,05:25:47
I've done some probing about with the 'scope.

The Power On / Off button connects directly to one of the pins on the socketed eeprom.

Scoping about all the pins on the eeprom shows some high frequency logic activity on just a couple of pins, all other pins sit at static logic levels and nothing changes when pressing the power on button.

That does not sound right to me, I would have expected a lot of logic activity on most of the pins.

My gut feeling now is to scrap the set and sell the psu and inverter, being the only bits that are easy to prove they work.

Any further suggestions?
Title: Re: Swisstec EJ20 stuck in standby (possibly AOC / Yusmart)
Post by: Turnip on August 23, 2010,13:03:10
Hi PD,

You don't say what these panels are - well -  Quuq folks might need to know - Chris.
Title: Re: Swisstec EJ20 stuck in standby (possibly AOC / Yusmart)
Post by: ProDave on August 23, 2010,15:32:50
Hi PD,

You don't say what these panels are - well -  Quuq folks might need to know - Chris.

It's my Swisstec 20" LCD television model Sky-EJ20/w/CG, the one the subject of the original post and thread.  I had some time to do some more probing about and was surprised at the lack of logic activity on most of the pins of the eeprom, leading me to suspect there's a lot wrong with it, and I was asking for more advice.