Insignia LCD32 No Power

[97wing]

Thanks to all that contribute to a forum like this.

I have an Insignia (Junk, I know) 32" that was obtained dead. I bought it for a few bucks thinking I could change a few caps and presto! I had done this on two other TV's with good luck.

Now the problem: When the power cord is plugged in, the LED blinks constantly every second. The color of the LED is a mixture of red, white and blue. I examined all boards with the microscope and saw no obvious board problems. I do have 5 Vdc coming out of the power supply board with all other boards disconnected. When I connect the logic board, (with all other connector unhooked) that 5 Vdc drops to 1 Vdc, pulsing a 1/2 volt.

On a long shot, I changed all the caps on the output end of the power supply. I used locally obtained caps just to see if it can be fixed. Upon fixing the TV, I will change these to the proper cap.

Attached are some photos. I can take better ones if needed... all I had today was phone camera.

Anybody have a similar problem?

Steve

[97wing]

Re: Insignia LCD32 No Power

I might add that the power button has no affect on the LED, or anything else.

[mbates14]

Re: Insignia LCD32 No Power

well if you go from 5V to 1v pulsating when plugging in the logic board, its a pretty safe bet you have a short in that there ol' logic board.

Either in the PWM voltage regulators on-board the mainboard, or possibly shorted IC.

might be easier just to swap in a new mainboard and be done.

[97wing]

Re: Insignia LCD32 No Power

I was afraid of that. Board cost too much to fix the TV in my opinion.

Another question:
Can I jump the 5 vdc on the power supply to make it come on line? On the main board connector, I have two yellows labed 5V, a white labeled P/S, and other 24v's, 12v's and grounds along with a Dim.

Is the signal from the main board sent back to the P/S terminal? Is it 5 vdc also?

Steve

[alexanna]

Re: Insignia LCD32 No Power

Thanks to all that contribute to a forum like this.

I have an Insignia (Junk, I know) 32" that was obtained dead. I bought it for a few bucks thinking I could change a few caps and presto! I had done this on two other TV's with good luck.

Now the problem: When the power cord is plugged in, the LED blinks constantly every second. The color of the LED is a mixture of red, white and blue. I examined all boards with the microscope and saw no obvious board problems. I do have 5 Vdc coming out of the power supply board with all other boards disconnected. When I connect the logic board, (with all other connector unhooked) that 5 Vdc drops to 1 Vdc, pulsing a 1/2 volt.

On a long shot, I changed all the caps on the output end of the power supply. I used locally obtained caps just to see if it can be fixed. Upon fixing the TV, I will change these to the proper cap.

Attached are some photos. I can take better ones if needed... all I had today was phone camera.

Anybody have a similar problem?

Steve

Spend the 12 bucks on the correct caps, including the small ones around the SMPS and see what happens.
Al.

[mbates14]

Re: Insignia LCD32 No Power

You can jump it to keep the power supply on, I did that to an olevia. only problem is, its going to appear "braindead"

I had a sony bravia giving me a blinking LED as well. comming up as DC-PROT on the 5V side.

Turned out to be a bad surface mount MOSFET pack on the mainboard. it was an FDS from fairchild.

Replaced that, along with its picofuse fixed the problem, set came on and played perfect. BUT only to discover it has a CRACKED SCREEN!!! :-(

oh well the part was only a buck 12 to fix the mainboard, and now i have a good spare mainboard for bravia, and the repair log from me for fixing the mainboard.

[97wing]

Re: Insignia LCD32 No Power

How is it jumped? Between which pins?

Steve

[mbates14]

Re: Insignia LCD32 No Power

power supply SHOULD be labled where the wire harness plugs into it.

youll see Standby 5V or SB5V or S5V something like that.

then youll see PS-ON. those 2.

[97wing]

Re: Insignia LCD32 No Power

I have the p/s board removed and no cables attached. I have a steady 5 volts on the 5 volt pin. I leave my meter there, and jump the p/s and 5 vdc. The volts fall to 4, and moving a 1/2 volt either way. I check the outputs and still have zero on 12 and zero on 24. I may still have a p/s problem and not a logic board?

[97wing]

UPDATE: Insignia LCD32 No Power

Well I found a logic board for $40 so I thought I would give it a try. It did solve the blinking LED and the pulsing 1 volt issues above... BUT, the power supply is still not switching on the 12v & 24v.

With all boards connected, I now have steady 4.9 on my 5v posts, and a steady 4.3v on my PS post. I replaced all the caps on the low voltage side with FM series. I did not change the high voltage side.(They are all Elite)

I included a photo of the bottom side of the board.

Any help will be appreciated.