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train123
PostPosted: Tue Sep 10, 2013 9:13 pm    Post subject:
It's pretty much a guessing game now as to what else might be wrong. I'm not sure what the value is of the TV where you live but a working one of those here is worth less than $100. It's your choice but it might be better just to put the money towards a new one or at least a working one. You might also get lucky and find another one cheap for parts.
Guest
PostPosted: Thu Sep 05, 2013 4:39 am    Post subject:
Hey Train, it took me a while to understand what you meant, I ordered and replaced the Tcon board, and still the same, any other suggestions? Is it feasible to replace the main board? Or should I say Cost effective.

Thanks & God Bless,
Glenn

train123 wrote:
Repairing the Tcon board is not likely cost effective. Take the TV apart to find out what the part number is for the Tcon (located at the center/top of the set. It is a bit of work to get to it but reading the part number right off the board is critical to getting the correct replacement. Google or check Ebay for the part and you'll likely find a cheap used replacement part.
train123
PostPosted: Wed Jun 19, 2013 12:23 pm    Post subject:
Repairing the Tcon board is not likely cost effective. Take the TV apart to find out what the part number is for the Tcon (located at the center/top of the set. It is a bit of work to get to it but reading the part number right off the board is critical to getting the correct replacement. Google or check Ebay for the part and you'll likely find a cheap used replacement part.
Guest
PostPosted: Sat Jun 08, 2013 7:31 pm    Post subject:
Train, Thanks for the reply, I bought this TV from a garage sale, the lady said it didn't work. I brought it home, plugged it in and it came on first try. But it only played for about 20-30 minutes and then the screen went blank. The sound stayed on, and you can see the backlight is still on, but no picture. Does that sound like the Tcon board? and if so, where is it and can it be repaired?

God Bless,
Glenn
train123
PostPosted: Fri Jun 07, 2013 9:16 pm    Post subject: To Glenn
Sorry, its been awhile since I've had a chance to check on this site.
If the set turns off and on, likely +5 volt is okay.
If the backlight turns on, likely +24 volts is okay as well.
If the set turns on, the sound is there, the screen comes on, but the only thing showing is a blank white or grey screen, it sounds more like your T-con board is acting up.
Guest
PostPosted: Sun May 12, 2013 7:57 pm    Post subject:
train123 wrote:
I've fixed dozens of these power supplies.


Train, do you know what the pinout for the power supply board is? My TV came on, worked for about 5 minutes and then I lost the picture. I can still see the backlight on, but no picture. I checked the caps and none are bulged like a bad cap. Thanks for any help you can provide.

God Bless,
Glenn
jts1957
PostPosted: Mon May 06, 2013 11:31 pm    Post subject:
I'm surprised they would let it leave the factory with defective bolts like that. Wink
CptHowdy
PostPosted: Mon May 06, 2013 10:25 pm    Post subject: @ N3251W Did-Assembly
Tip to others. . . when disassembling my 3251 i noticed i had to remove the stand prior to separating the back panel. . . . and in order to do this effectively, I hat to drill in the centers of the bolts holding the stand on and using an "EZ Out" set from the nearest auto parts store. . . . then either replace those bolts with flat head style or use a cutting disk and cut a notch in existing bolt heads just big enough to fit a flat screwdriver.
train123
PostPosted: Mon Mar 18, 2013 12:23 pm    Post subject: Re: Viewsonic tv32 power supply
Jamesunshine wrote:
Hi everyone i was wondering if somebody can help me fix my viewsonic tv power supply FSP228 - 3F01 i change all the bad capacitors already and all i need to change is Q7 but i dont know thats the part number and the name of the parts please help.thanks

Q7 is a transistor MMBT4401 or you can also use a common 2N4401 and carefully bend the legs so that the pinout is the same.
train123
PostPosted: Mon Mar 11, 2013 12:46 pm    Post subject:
Anonymous wrote:
jts1957 wrote:
That's sort of like asking for Goodyear Assurance TripleTred tires for your car and not being sure of the size. Most people would use their common sense and tell the salesperson: "The same size that is currently installed on the vehicle."


Zener diodes are somewhat more flexible. Just get one that is the same (or larger) wattage as the one you pull out. Usually is also the same physical dimensions. Bear in mind that replacing a smaller physical size or wattage with a larger physical size or wattage is also perfectly OK (IF space/time/wallet allows).


1st all tires have the size on them glass zener diodes do not.

2nd all tire companies have access to all vehicle tire sizes, electronic shops do not have access to all schematics for all electronics.

3rd physical size means absolutely nothing.

4th a lower wattage can fry the ZD, a higher wattage can fry other components it is feeding. (confirmed by 2 tv repair shops and 2 electronic shops). I am not an expert so .50 for the right component or guess and blow $50. for a new PS.

I bought the full schematics online and now have the correct answer.


jts1957 is correct, your local shops are not. You might have had 2 shops give you that answer but you need to ask the right question before you get the correct answer. As a Electronic Technologist, I know that that zener's only job in that circuit is to establish the operation voltage of that voltage regulator. Using one too small could lead it to burn out again but bigger is fine. I've fixed dozens of these power supplies and just use a common 1W zener in that location. Also, when it comes to electronic parts, physical size means a lot since a larger size is needed to handle heat dissipation of the higher wattage part. A smaller part usually indicates a lower wattage unless a heat sink is provided to handle the heat. Don't be too hasty is judging the people on this forum, they've likely been doing this for a lot longer than you have.

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