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Old 11-15-2013, 04:03 AM   #1
tn245
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Default Vestel 17PW25-4 repair - resistor value?

I bought a repair kit for this TV power supply. Shorted diodes, FET and several tiny surface mount components to replace. On starting the repair I noticed someone had had a try before me and even helpfully ripped up some of the PCB pads. In spite of that I think I've managed to get everything in place and connected up correctly.

My question. The schematic for this power supply (attached) lists SMD resistor R923 (off pin 4 of FAN7529) as 15R, but the repair kit supplied 100R and the one I removed from the board was also 100R (bearing in mind someone had repaired it before - maybe with same kit?). I wrote to the kit supplier to ask about it and he hasn't replied.

As I don't have the electronics knowledge to know what that resistor value should be, do you think there's any reason a 100R might be supplied instead? If I go ahead and use 100R might there be any consequences?

Thanks!
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File Type: pdf vestel_17pw25-4.pdf (141.9 KB, 209 views)
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Old 01-01-2015, 06:10 AM   #2
Klockaren
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Default Re: Vestel 17PW25-4 repair - resistor value?

Quote:
Originally Posted by tn245 View Post
I bought a repair kit for this TV power supply. Shorted diodes, FET and several tiny surface mount components to replace. On starting the repair I noticed someone had had a try before me and even helpfully ripped up some of the PCB pads. In spite of that I think I've managed to get everything in place and connected up correctly.

My question. The schematic for this power supply (attached) lists SMD resistor R923 (off pin 4 of FAN7529) as 15R, but the repair kit supplied 100R and the one I removed from the board was also 100R (bearing in mind someone had repaired it before - maybe with same kit?). I wrote to the kit supplier to ask about it and he hasn't replied.

As I don't have the electronics knowledge to know what that resistor value should be, do you think there's any reason a 100R might be supplied instead? If I go ahead and use 100R might there be any consequences?

Thanks!
Hi,
I have the same problem regarding R923. I havent got any schematics with the right value for this resistor.
Then R980 are broken and I can't see the numbers on it. Schematics says 15R for this also, but I don't trust on this.
Do you got any correct schematics for this board?
/Gunnar
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Old 07-31-2015, 12:02 PM   #3
steviewonder
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Default Re: Vestel 17PW25-4 repair - resistor value?

bit of a old thread,but just had the same problem.
R923 is indeed 100 ohm,the schematic is incorrect.
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Old 07-31-2015, 06:49 PM   #4
budm
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Default Re: Vestel 17PW25-4 repair - resistor value?

15 Ohms or 100 Ohms is not going to make any difference, the there is 40K internal resistor/Capacitor filter feeding the input of comparator circuit inside for that Current Sensing (CS) pin. if you look at the app note circuit, you do not need the resistor.
Attached Files
File Type: pdf FAN7529.pdf (1.69 MB, 4 views)
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