Re: Testing diode bridge and FET - epilogue

Success. Replacing the T3 fuse and 2KBP206 diode bridge returned the LCD monitor to service. You were right. Thank you for helping me through this repair.

By the way, while shopping for diode bridge replacements I saw KBP206 ( no leading 2) with the same amperage and voltage ratings as the original 2KBP206 I was replacing. The data sheets show they differ in withstanding repeated voltage peaks. How critical are these differences and could I have used them as replacements?

Tom G

Re: Testing a transformer

My goodness, you respond quickly.

I wanted to add that IC201 (Reads LD7575PS / 0630AH) is a D7575PS, PWM Controller? for others following this thread. Thank you again.

Tom G.

Re: Testing a transformer

We have to determine why the fuse blew...

Step 1
Replaced fuse. Plugging in board blows fuse F201. Replace fuse and Go to Step 1B

Set VOM Multimeter to 2k OHM scale:
Step 1B
Resistance on Diode Bridge BD201 (2KBP06M):
1-2, 1-3, 1-4, 2-3, 2-4, 3-4 (Pin 4 is at the top, Pin 1 at the bottom, 3-prong socket facing me)
(Red <+> lead on lower pin number, OHMs) 1.03k,0.0,958,open,1.05k, 953
(Black <-> lead on lower pin number, OHMs) open, 0.0, open, 1.02k, open, open
...

Re: Testing a transformer

Hi,

I missed a slow-blow T3 15A fuse that was open. I didn't know they could look like little terra-cotta colored blocks. I will update if a replacement is found and works. I feel like such a fool.

Re: Testing a transformer

Hi,

I think the fault might be on the power/inverter board because after applying AC through the three prong connection, the ten-pin connector between the two boards reads zero volts among all the pins. At this point, are there any suggestions? TIA.

Re: Testing a transformer

Please help.

After replacing bad capacitors and failing CCFL's, my LT1919WDB has suffered a relapse during a local lightning storm surge. It was on a surge suppressor but the surge was enough to require rebooting my computer. The computer was OK. But the monitor was rendered unresponsive to the power button.

I've checked diodes and such but haven't found anything to explain or fix. I did check D203 out of circuit, after a suspicious in-circuit reading; but it seems fine. Large fuses and some the small SMD fuse are still conductive....