Samsung 23" LCD P2350 Inverter Repair

[Dgtech]

Re: Samsung 23" LCD P2350 Inverter Repair

Replace the five "Sam Young" midsize caps on the board and then try it again. These caps have gone bad for me in the past without bulging.
They look like they are 1000uF 10V caps. I'd replace these with 1000uF 16V's - if they will fit.

[whistlergonewild]

Re: Samsung 23" LCD P2350 Inverter Repair

Im now having even more difficulties. The monitor now only stays on for a minute and stays off for 4 min before automatically turning on again. This is reverse to how it was previously.

[whistlergonewild]

Re: Samsung 23" LCD P2350 Inverter Repair

ok, so I tried to resolder the board, and it is still turning on and off. I find that it is shutting off sooner and now taking longer to turn back on. I have included some photos for you to view. Do you see anything wrong with any components??

This is the Samsung 2350, IP Power Board BN44-00297A

[alexanna]

Re: Samsung 23" LCD P2350 Inverter Repair

I am having an issue with my monitor (samsung p2350) Turning off every 5 minutes, and turning back on a minute later. Very annoying. All the caps look good. Any sugestions, greatly appreciated.

I would suspect a problem with a solder joint, possibly around the SMPS transformer. I would try adding fresh solder to that area, see if anything changes.
For the monitor to shut off and restart one or more of the voltages to the logic board has to be changing, It's probably time to get the voltmeter out and try to identify which one.
Pictures would really be helpful; a good top down shot of all the boards high detail without a flash would be the best, using managed attachments.

[whistlergonewild]

Re: Samsung 23" LCD P2350 Inverter Repair

I am having an issue with my monitor (samsung p2350) Turning off every 5 minutes, and turning back on a minute later. Very annoying. All the caps look good. Any sugestions, greatly appreciated.

[Dgtech]

Re: Samsung 23" LCD P2350 Inverter Repair

oh almost forgot... logic board also overheats....

How was it determined that the board overheats? Do you smell anything burning, or does anything feel hot? You may have to replace the whole board but in a 23 inch LCD, it may not be worth it.

[smason]

Re: Samsung 23" LCD P2350 Inverter Repair

That's one ugly repair, but I'm impressed. Nice job!

[k0i_]

Re: Samsung 23" LCD P2350 Inverter Repair

oh almost forgot... logic board also overheats....

[k0i_]

Re: Samsung 23" LCD P2350 Inverter Repair

iv'e got the same model... my problem is the backlight shuts off... i replaced all caps that i suspected, but still i get the same results... help

[momaka]

Re: Samsung 23" LCD P2350 Inverter Repair

Those replacement MOSFETs are HUGE! That's a good thing, though; you definitely won't be seeing them burn out again. More likely the power supply will melt before these go bad .

[jetadm123]

Re: Samsung 23" LCD P2350 Inverter Repair

Very clever fix!! Thanks for sharing.

[Dgtech]

Re: Samsung 23" LCD P2350 Inverter Repair

It doesnt have to be pretty, it just has to work. Those mosfet's dont need a heatsink?

[erbmit]

I bought this dead monitor on spec on Ebay.

Found the two tiny 8-pin SMD dual complementary AM4512C backlight inverter driver mosfets shorted all terminals. No other problems visible or measured. Removed the inverter transformer, and it seemed oddly wired to me but I couldn't fault it.

No replacement mosfets obviously available in Australia, so I bought 2 IRF540N and 2 IRF9540N discrete mosfets from Jaycar, & soldered them in, held only by the drain lead. Luckily there was space for them on the solder side of the board where the originals were.

The monitor has now been running for 5 days, no problems at all. Pics attached.

The originals were rated at 1W and 2W per mosfet, the replacements 130W and 140W per mosfet.