viewsonic 32in lcd tv power supply broken

JRnTX · Joined: 26 Jun 2008 Posts: 1

I just repaired an FSP 212-3F01 power supply in a Viewsonic N3250W. I have seen the same power supply listed for the N3235W. This one was totally dead with no 5V standby present. The problem was a shorted internal voltage regulator made up of Q7 and ZD4. The Q7 is a SOT23 size device and appears to be too small and over heats in the design. In this case it shorted from the over heating and that caused ZD4 to fail and shut down a 15V bias supply on the power supply board. I replaced Q7 with a 2N4401 to give it more power capability. Any small NPN transistor with a 25V or higher Vce rating will probably work. ZD4 is a 15V zener diode. Note that there appear to be two or three power supplies used in these TVs. This fix may also apply to similar FSP power supplies such as the FSP 228 but that has not been verified.

Ocean-Tech · Guest

Fspgroupusa.com (california location) offers repair of these power supplies for 15$, they also import them from the factory for a very cheap price but possibly a wait time. We were quoted $22 ea for 30 power supplies FSP 212-3F01 .Wait time is about 2 months.

alain28 · Joined: 27 Jan 2008 Posts: 32 Location: France

Sorry I don't visit here often....
For above and modify a power supply I don't order because very busy
with many things....other than electronics but sometime electronics.

I have been contacted by 3 persons at least and curious these 3 within last 2 weeks....
STEVE have made the replacement by
Moniserve part number is 4H.B0280.001MSS(MS93PW)
Nice but expensive.(his total cost 149,98$) but better than replaces a 1 to 3 years TV.
He just send me the pictures of his change. I will add soon on my webpage!
For 2, I send N3856VAG but it is not the good solution...
If somebody can send me a broken Darfon PSU, I will pay shipment, send me an e-mail !!!
_________________
AM

France

alain28 · Joined: 27 Jan 2008 Posts: 32 Location: France

The 2 persons (France, USA) have received their N3856VAG.
Replaced on the PSU and all is working well.
Anyway we cannot know the origin of the failure.

Steve ( USA ) have sent me his Darfon PSU free of charge.
I will try to investigate but not for the moment.
For the pictures from Steve on his PSU replacement I have started the WEB page be realy a draft incomplete.(french version)
http://pagesperso-orange.fr/mionnet/ii3210jbis.htm
_________________
AM

France

LamSV · Guest

Hello,

Thanks to this forum, I repaired my N2751W. It broke down due to a PSU (FSP212-3F01) failure from overheating. I bought a brand new factory replacement FSP212-3F02 (about US$49) from RamPlus.Com. However, the FSP212-3F02 does not have the soldered on wiring to a 12pin female connector. It comes with 2 males connectors, 10 pins and 12 pins. For the 12 pins, I tried to buy the 12 pins female connector but in vain. Instead, I did the unthinkable (I'm an EE engineer). I physically soldered the 12 wires to the PCB (underside) and connect the wires to the old connector (cut off from FSP212-3F01). The appearance is ugly but it works. TV is now back in operation. You need to be careful during soldering because the traces are very close together. Also be aware of the pin-out orientation between the FSP212-3F01 and 3F02. They are different because one count from right to left and the other from left to right.

My request for help - can someone tell me what are the specifications (manufacturer model/part no.) of the output connectors (10 pins and 12 pins)? Will be useful information for other forum members.

Houston, TX

Dale M · Guest

lamSV - thanks for posting that information about the connector differences. I almost bought one of 3f02's and saw your post . I think I'll just hit up ebay for one of the 3f01's and save myself some time. I also have the Viewsonic n2751w and there doesn't seem to have any voltage output at all. Thanks for all the information in the thread-it saved me a lot of trouble

cattlerepairman · Guest

I have a ViewSonic n2750w with the same symptoms:

- for a while, it would switch on and switch itself off after about 5 seconds. The picture would be normal during this time and the green LED would be on

- it got progressively worse, with unplugging and 10x restart needed until the picture stayed on

- now, green LED comes on, but no picture

Getting the exact match for the power supply appears impossible; I will try the PS from a 2752 and see if I can make it work.

alain28 · Joined: 27 Jan 2008 Posts: 32 Location: France

cattlerepairman · Joined: 24 Oct 2008 Posts: 1 Location: Canada

Alain,

I opened the TV and carefully removed the PSB for inspection. The type is FSP 204-2F01, Revision 1, dated 05/21/10.

I cannot see any obvious defect. The capacitor tops are all concave, none is bulged. I cannot see overheating marks. Nothing is "obvious".

FSP still makes this board: http://www.fsp-group.com/english/1_product/2_detail.asp?mainid=47&fid=72&proid=247

I searched, but no supplier seems to have them. I think I need to find a board where I can make the connectors to fit....

Guest