ViewSonic N3250W Television with FSP212-3F01.dead needs VOODOO
I have a ViewSonic N3250W Television with FSP212-3F01 power supply. The power supply looks OK no visible caps problems no burn signs. I get the 5 Volts output OK but not the 12 Volts or 24 volts. The red stand by LED turns on for one second and then fades OFF. Viewsonic manual says check first 5 presence of 5 Volts and 12 volts and replace power supply if that is not the case. I'm puzzeled by the fact that the Power on signal is low. If I force it to high I get both the 12 and 24 volts on. So that seems to indicate that it's not the power supply. both BL_ON_OFF and IADJ (on power supply P100 collector) are low. I've been looking at this TV for more than a week now and I'm running out of options. The big dilemma semms to be if it's indeed the poer supply or other board. I have the schematics including some not so fully power supply schematics so this should be fine. It might be that the power does not send some signals to other components and those components in turn set the poewr on level to off. Maybe some kind of protection... It kind of starts to bugs me a lot so any help would be appreciated. I'm not a professional TV repair but I can do measurements, sodering etc...
most caps on the power supply (FSP212-3F01 ) are CapXson. The main board caps are a different brand.
Thanks in advance Adrians
most caps on the power supply (FSP212-3F01 ) are CapXson. The main board caps are a different brand.
Thanks in advance Adrians
Televison & Video - ViewSonic - N3251w 32 in. LCD HDTV
Answers & Comments
I am working on the same power supply right now, my has a bunch of bad caps that I already replaced but I did not try to turn it on yet becuase I see that RS1 and RS8 are missing, some one had try to fix this power supply. Can you please tell me the value of these two resistors? Please see my pictures at http://s807.photobucket.com/home/budm/allalbums
Your problem sound like the logic board problem, I can tell you what you should have if I can find out if these two resistors were left out from the factory or some had removed them. I fixed the same power supply for the N2652 but I did not take the pictures of the board, I wish I did.
It is ZENER DIODE 15V 1/2WATT. I worked on another one that has bad transistor and zener. http://s807.photobucket.com/albums/yy352... N3250W/
Maybe it would be easier to buy a new power supply. The FSP212-3F01 has been discontinued by FSP, and replacement model is FSP212-3F02 with a cable made to work with the 3F01. You can buy this at ramplus.com
I had same problem the power supply dead (FSP212-3F01) Replace zd4 (15volt zeiner) and Q7 (2n4401) I get the 5 Volts output OK but not the 12 Volts or 24 volts. {Q11(MMBT4403) supplies the power for the IC's controlling (L6598D) the +12/+24 outputs} check Q11 had 14.7V on both B & E the C had 0 when is standby when turn on green LED light, check Q11 again had 11.7V on both B & E the C had 7.4V (normally B & E & C had 13.5V) I order Q11 when is come in to replace and post
This is really not a "pro solution" but I had a very similar power problem with an all in 1 surround sound system (I know not same but power-wise). Anyhoo it was a large ceramic type resistor that had fried. I initially found it with the "sniff test" (use your nose and save some time tracking down the culprit). I would also highly suggest testing the adjacent voltage regulators if you have the means as it also caused one to eventually fail. This leads me to believe the original resistor failure to give it a mere "flesh wound" that opened up after repeated use. You sound like you know what you are doing for the most part. AS ALWAYS UNPLUG WHAT YOU ARE WORKING ON. NO POWER. Double check your resistor band values. Best of luck friend :)
Replace all the caps on the power and ZD4 and Q7 fixed my it had no power at all
Replace zd4 (15volt zeiner) and Q7 (2n4401) you will be good to go.
Replace all caps on power supply and ZD4 and Q7 on the bottom of the power supply and my tv is working it had no power at all ViewSonic N3250W