Mulja tv repair portal
Equipment Repairs => LCD TV forum => Topic started by: gatis on December 04, 2011,10:10:38
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I have problem with VESTEL 17MB2 (branded as MATSUI). When switching power on, all STBY powers are up and OK. CPU three times switching on all VCC in approximately 10s time and after that no more any reaction, just blinking LED. In that start up time nothing happen on screen or speakers. Does anyone has ideas what need to look next?
:17:
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Hi Gatis,
What model, and power/inv panels fitted - Chris
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Hi Chris,
There is fitted VESTEL branded inventor board 17INV16-1. I tried switch on with plugged and unplugged inventor board. Not seen any differences.
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hi
post a pic of psu
dave
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Hi Dave,
There is no problem in the PSU. It is external 12V and works fine. Picture of Chinese made a black box will show nothing. All internal powers (12, 8, 5, 3.3, 1.8, 1.26) forming on the main board.
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have to agree with Chris with these wee budget 12v dc sets the inverters are a regular fail
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12V to inverter board coming directly from PSU and is OK. There just two additional one direction signals BACKLIGHT_ON/OFF where is low level all time and DIMMING where happening same as in all system, after switcing ON, three times stay high level (3.3V) and then go to low level. I would like say that I can't see any feedback from invertor board whay all system halt even if it is assumed that the invertor failing.
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quite often on these wee inverters if the inv. chip, a mosfet or indeed the coil, some have 1 some have 2, are faulty the error reporting circuit built into the main chip on the inverter relays this info to the processor and the software goes into protection mode and prevents the set from booting up. there are several known faults on these wee inverters so if you let us know which one it is we may be able to point you in the right direction
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Here are pictures of the invertor.
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sorry i dont recognise that one off hand try removing c900 and see if it powers up
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I removed C900 (12p/3kV). No any change :(
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have a read at this see if it helps
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check around page 10 thats most of the power and protection components
Just out of curiosity are you sure on the 17mb25 bit ( the number of the main board ) as the manual for a 25 shows its powered by a inv/psu combination an IPS unit not 12v external ?
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Thank you for schematic! I used same. Yes, it is definetely a 17MB25-1 board. That printed on the board. May be original VESTEL TV using something as you told, but this is MATSUI M16LID709. As I found same look has ALBA LCD32HDF. How fare I understanding protection circuit so everithing seems ok. PROTECT all time in low level, but PROTECT_PANEL in high level and there no any changes at all. Here no any another signals which used for power failure protection detection.
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on page 5 you'll find teh inv. and dimming circuits check there , you could try a hard reset of the eeprom. Solder a wire onto pin 5 and another onto pin 6 join then , start up . unplug from supply. disconnect wires , reassemble and switch on as usual.
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I been litle bit surprised for that kind of resetting. I put the EEPROM 24C32 pins 5 and 6 together. After that operation nothing changed. Can be here any problems in Flash memory content? My experiences more related with PC and there so usual situation that flash memory content, which contain system firmware, are corupted.
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hi i think this is the one you're after double check and if it is and you want it pop a tenner in my pay pal and i'll send it off to you cheers
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Electronic part of the board in pictures looks same, but all connectors are slightly different. Yours board has 17MB25-3 mark, but my 17MB25-1. There will be little bit tricky job resolder all connectors. One else, may be there is diffrent firmware, because my board consist the connector for DVD. Anyway how much you would like, because I must consider that with customer.
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as i said your welcome to it , no charge just give me £10 via paypal to cover postage packing etc
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I finaly found problem. Shortage was in 5V_TUN line, but funniest ... in the LG made TV module. TV module cover was completely soldered and I just swaped with same type another. One else think, 17MB25-1 board can't staright away change with 17MB25-3. On 17MB25-3 not soldered +5V and +3.3V PSU as well as DVD interface.