LG Flatron L1933TR

[hardwareguy]

My friends monitor is going under the soldering iron tonight. It made weird squealing noises about a month before it died outright.

Its got two bulged Samxon GF series caps, no surprise there. There is no pi filter on the +12V rail! There's a spot for an inductor, but its just jumpered! The 5V rail has a pi filter.

Due to this lack of a pi filter, Im going to order some high ripple caps...probably some Nichicon HV.

Values are as follows:
C202: 25V 1000uF
C203: 25V 680uF
C204: 16V 1000uF
C205: 16V 1000uF
C206: 25V 1000uF
C207: 25V 470uF

C103 is also a GF, 50V 33uF. This looks like a pull up cap for the SMPS controller which is an FAN7601. The inverter output stage is weird. Each xfmr is driven by a 4511GD MOSFET in a strange 8 pin DIP package. These things get HOT; the board is discolored! TO220 would have been a better choice.

[EGuevarae]

Re: LG Flatron L1933TR

My friends monitor is going under the soldering iron tonight. It made weird squealing noises about a month before it died outright.

Its got two bulged Samxon GF series caps, no surprise there. There is no pi filter on the +12V rail! There's a spot for an inductor, but its just jumpered! The 5V rail has a pi filter.

Due to this lack of a pi filter, Im going to order some high ripple caps...probably some Nichicon HV.

Values are as follows:
C202: 25V 1000uF
C203: 25V 680uF
C204: 16V 1000uF
C205: 16V 1000uF
C206: 25V 1000uF
C207: 25V 470uF

C103 is also a GF, 50V 33uF. This looks like a pull up cap for the SMPS controller which is an FAN7601. The inverter output stage is weird. Each xfmr is driven by a 4511GD MOSFET in a strange 8 pin DIP package. These things get HOT; the board is discolored! TO220 would have been a better choice.

I've worked with that units in the past: be sure to replace that little guy (C103), as it has given me trouble more than once.
Eduardo

[hardwareguy]

Re: LG Flatron L1933TR

The little one got changed as well...since I had to order in caps, not ordering a $0.20 capacitor for a $200 display would have been stupid.

I ended up using a mixture of Nichicon HV and HM (new stock of course!) due to supply issues with the HV series.

The 50V cap was a UCC KY series IIRC.....any low ESR will work.