Mulja tv repair portal
Equipment Repairs => LCD TV forum => Topic started by: lineofstars on November 10, 2014,06:32:51
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Hi everyone.Im new here and obviously need your hand of help.
Suddenly the TV start making a strange sound to the speakers,than there the sound has gone.The speakers I have checked them connecting to other device.The audio jack output also does not work because I have tested with an earphone.
The exact tv model and info are:
Blaupunkt TV,model # W23/173I-GB-FHBKUP-DE
Ref B23C173TCFHD
Product code BW23R173BFBKPE404
Serial Number BW23R173BFBKPE404-107426 00808
Motherboard serial t.msd309.28b
Photos link to see the motherboard:
https://plus.google.com/photos/102793503591974069148/albums/6079107146329663217/6079107625735817218?pid=6079107625735817218&oid=102793503591974069148
https://plus.google.com/photos/102793503591974069148/albums/6079107146329663217/6079108071896586770?pid=6079108071896586770&oid=102793503591974069148
https://plus.google.com/photos/102793503591974069148/albums/6079107146329663217/6079108387635073554?pid=6079108387635073554&oid=102793503591974069148
https://plus.google.com/photos/102793503591974069148/albums/6079107146329663217/6079108753207936914?pid=6079108753207936914&oid=102793503591974069148
https://plus.google.com/photos/102793503591974069148/albums/6079107146329663217/6079109117947711538?pid=6079109117947711538&oid=102793503591974069148
https://plus.google.com/photos/102793503591974069148/albums/6079107146329663217/6079109475267788786?pid=6079109475267788786&oid=102793503591974069148
https://plus.google.com/photos/102793503591974069148/albums/6079107146329663217/6079109887551514674?pid=6079109887551514674&oid=102793503591974069148
https://plus.google.com/photos/102793503591974069148/albums/6079107146329663217/6079110207183580290?pid=6079110207183580290&oid=102793503591974069148
https://plus.google.com/photos/102793503591974069148/albums/6079107146329663217/6079110569102090482?pid=6079110569102090482&oid=102793503591974069148
https://plus.google.com/photos/102793503591974069148/albums/6079107146329663217/6079107550650379634?pid=6079107550650379634&oid=102793503591974069148
https://plus.google.com/photos/102793503591974069148/albums/6079107146329663217/6079107148706017746?pid=6079107148706017746&oid=102793503591974069148
There are 11 close up high resolution photos totally.First one shows the the entire board.
Wich is the step by step procedure to repair it?
What components make the audio circuit exactly?
Thanks in advance.
Peter
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Hi your best option is to replace the main board.
http://www.ebay.co.uk/itm/MAIN-BOARD-TV-T-MSD309-28B-11235-/251673717340?pt=LH_DefaultDomain_186&hash=item3a98ec2a5c
U15 looks like it may be the audio amp IC, check for supply voltages to the chip, use an oscilloscope to check for audio input. try to inject an audio signal in to the IC and see if you get an output.The microprocessor chip or associated circuit could also be faulty as this will control the volume, the eeprom or flash data may also be corrupt.
Best to change the board!!
Keith
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Hi Keith.
Thanks for the ebay motherboard link you provided.Amazing because the board is right in Madrid,20km away.
But really ,to replace the hole board just for the IC YD 1517p FTBfY,....,its a bit wastey.
maybe I will be able to find the same IC,see the datasheet of it.If not,do you know an equivalent?
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It is actually a TDA1517P,
Good luck
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Hello,
Have you checked the electrolytic capacitors near the
TDA1517?
I had one that was short circuit and was shutting the IC down,
worth a check before changing the PCB.
Regards
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@watteau
I dont have a multmeter that can check the capacitors.
But on the board,they look good.
First ,with your help,I want to see IF the IC YD 1517p is good.
So,I already attached the datasheet of the IC but I will make a screen shot and I will attach here the IC diagram.
Turning the TV on, I have checked the voltage using the multimeter,the values are:
Vcc=12 to pin#7
1/2Vcc=0 to pin#3
Rest of the pins voltage=0.
Turning the TV off, In diode mode by multimeter with the black probe to GRD and red probe to the pin
#1 value is 796
#2 it beeps
#3 value is 796
#4 it beeps (why?)
#5 it beeps
#6 value is 792
#7 value is 1755
#8 starts from 1800 and goes to OverLimit
#9 value is 797
#10 to #18(the last pin that the IC has) it beeps cause is the GRD.
Turning the TV off, I have checked the resistance Ω(ohm mode) by multimeter with the black probe to GRD and red probe to the pin
#1 value is OL(over limit)
#2 value is 0
#3 value is OL
#4 value is 10 Ω ohms
#5 value 0
#6 value is OL
#7 value is OL
#8 value is OL
#9 value is OL
#10 to #18 value is 0
Based on this measurements please give me a hint about what is your idea if the IC is good,or guide me to do other measurements,or technics using the multimeter,beacause I only have this kind of measurement tool.
Are the above values correct?
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The link of the IC's datasheet is:
https://drive.google.com/file/d/0B72PSl5kuidmSTBQQ3g0eTZkVDQ/view?pli=1
So you can see the exact values of the manufacturer.
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try disconnecting speakers and see if volts appear on 4 and 3 if not suggest replacing ic also does it get hot to touch output pins are connected with a capacitor in series with speakers may be one leaking also cap on pin 3
suspect
regards
astracat
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Thanks for replay astracat.
All the measure were done with the TV on, without the speakers connected to the white 4pins slot.
Accordingly to the BLOCK DIAGRAM attached above, the pin#3 is 1/2Vcc.
So the Vcc in the datasheet(see the google drive link),shows 14.4V,therefore the pin#3 of the audio IC in question,suppose to have 7.2V,but shows 0V.
Question for ASTRACAT,pin#1(IN1, pin #4(OUT1) pin#6(OUT2),pin#9(IN2) ,wich is the voltage expected?
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hi
both output pins should be virtualy same voltage also change cap on pin 3 if no better suggest ic u/s but first isolate mute pin to make sure micro not turning it off it could still be memmory ic problem ,with mute isolated probe inputs should give a buzz from relevant speaker .note ic still possible suspect if buzz there then mem ic
regards
astracat
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@astracat
"both output pins should be virtualy same voltage",still I do not get what value must have pin#4 and 6 with the TV on.
Please specify it.
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hi
pin 4 should not beep as 10ohms speaker not disconnected if diconnected ic probably s/c internaly remove pin 4 from its connection if still beeps or 10 ohms ic definatly s/c only way to be sure is change it output pins will vary with signal on inputs ,have had this ic u/s before its easier to check with a scope
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Hi everyone.
I have changed the 100uF capacitor wich is in connection with pin#3 of the audio IC YD1517P.(see the datasheet link above)
I have changed the IC too.
But despite my effort,still no sound.
Any clue?
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What voltage do you have on pin 8?
Keith
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I have explained above.
Pin#8 shows 0 voltage.
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Pin 8 is the mute / power on control, it needs to be a minimum of 8.5V for the IC to turn on. You could have a microprocessor fault or corrupt eeprom data causing it to mute.
Keith
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Thanks Keith.
I just foud the IC datasheet(above link), wich is not enough.
My question is if you can give me a link from where I can download the hole electonic Diagram service manual of the mainboard T.MSD309.28B 11235 ,the microprocessor and eeprom IC.
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try lifting mute pin and put a voltage on it ,do the speakers buzz with a signal on inputs if so try a reset back to manufactory still possible that software corrupted
astracat
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@astracat
Good idea to reset to the factory state.
never crossed my mind....