Only Power LED on when power on

psu replaced with known good power supply no change
cmos either reset or pull the battery to reset it no change
checked motherboard led for power. power supply led for power.
then start unplugging things from the motherboard. any cards plugged into slots checking each time to see if it powers up. was there a storm that could fry one of them.

Those blinks [flashes] are fault indication (Error Codes). From the number of blinks occur at one time switch ON, you can get an idea about the faulty circuit section inside it. This will make repair easy. These are called blinking codes. Make sure about the exact number of blinking of the standby/power LED, by switching On & OFF the set, for at least two times. Count it carefully. If you wish to get some details, check the site linked here. It has details about blinking codes, and fault locating procedure, to many popular brand TVs and other devices.
http://electronicshelponline.blogspot.com/
If blinks continue without any pause, the main board is faulty.
Search the site by type in the "brand name" to your device, in the "Search box at the top right of the display window of the Homepage" to get gathered related posts.

Are you getting 160vdc voltage on that new cap?
How about the cap in the secondary DC side for the 5v and the 12vdc?
It also not good idea to double up on the capacitance since the in-rush will be higher when this cap is charged up and it can blow the main AC fuse or damage the bridge rectifiers, 10~20% higher will be OK.
When the DC filter went out, the circuits will be fed with AC and it can damage the circuits.
Service manual; http://elektrotanya.com/?q=showresult&megnev=HP&megnev2=L1706&kategoria=monitor&kat2=all

http://s807.photobucket.com/albums/yy352/budm/HP%20L1706/
Need more details on the DC reading.
Basic LCD monitor and TV troubleshooting guide:
http://www.fixya.com/support/r5093881-lcd_flat_panel_tv_troubleshooting_guide
http://www.fixya.com/support/r6150077-basic_lcd_monitors_troubleshooting
http://www.fixya.com/support/r7406380-tv_training_manuals
Failed TV and Monitors: http://s807.photobucket.com/albums/yy352/budm
Learn about bad caps: http://en.wikipedia.org/wiki/Capacitor_plague
Parts: www.shopjimmy.com
Capacitors kit: http://lcdalternatives.auctivacommerce.com/Default.aspx he can make you a set of caps.
Or www.digikey.com, just make sure to use caps with low ESR, 105c, high ripple current and long life rating such as PANASONIC FM or FC series.
Please post back what you find.
Please leave rating if it helps.

http://s807.photobucket.com/albums/yy352/budm/Samsung%20205BW/

Attach a 12v bulb to the 12v output of the power supply, do not turn on the power switch because we just wan to lod the power supply with the bulb only, see if the lamp cycle on and off.
Check the DC voltage on the large cap (the one with 250~350vdc rating) on the AC primary side, it should have about 160vdc on it.
Use the hair dryer set to low and heat up the small cap by SMP IC on the heatsink as shown in picture DSCF0585 to see if the output 12vdc is on steady.

All the caps have flat tops and you replace them as a set?

Basic LCD monitor and TV troubleshooting guide:
http://www.fixya.com/support/r6150077-basic_lcd_monitors_troubleshooting
http://www.fixya.com/support/r5093881-lcd_flat_panel_tv_troubleshooting_guide
Failed TV and Monitors: http://s807.photobucket.com/albums/yy352/budm/

Learn about bad caps: http://en.wikipedia.org/wiki/Capacitor_plague

Capacitors kit: http://lcdalternatives.auctivacommerce.com/ he can make you a set of caps for you.
Or www.digikey.com just make sure to use caps with low ESR, 105c, high ripple current, long life rating such as PANASONIC FM or FC series.

Check the DC filter caps first.
If you are going to DIY and have proper tools and know safety precaution then please read on:
Most common failures in the LCD monitors are bad capacitors (bulging top/seal or leaking) in the power supply, blown fuses; poor solder joints, failed inverter circuits (blown fuse, shorted transistors, shorted/open transformers), bad lamps (poor solder connections or worn out lamps). You will need to open it up and inspect the inside, see example of failed monitors to get some ideas what to look for: http://s807.photobucket.com/home/budm/allalbums
Post back what you see inside so we can guide you further and it will help out other people in the future also.
http://en.wikipedia.org/wiki/Capacitor_plague
http://www.badcaps.net
Capacitors kit: http://lcdalternatives.auctivacommerce.com/

Its either going to be the power board or the main board, My assumption would be the power board since those are the more lilely culprits to go out on those monitors.

Since neither one is readly available, check the fuses on the power board and then also see if there are puffy caps. If there is then replace them with ones that are the same UF rating and same or highter voltage.

Common failure is the caps in the inverter/power board, look for caps with bulging tops, see example of failed VIEWSONIC monitor due to bad caps: http://s807.photobucket.com/home/budm/allalbums

Hello,

You have monitor with a very common problem, a dead power supply. After 2-3 years many LCD monitor power supplies will fail just like you have described. The problem is caused by parts called capacitors overheating in the tight space of the monitor case. If you can solder then you should be able to do the repair yourself. We will have a repair guide posted 12/29 after about 5:00 central time that should get you back going again. The repair guide will be on our web site at: www.ccl-la.com If you have any questions please let me know at the address below.

I hope this helps, if so please rate our solution.

Buddy
Corporate Computer
www.ccl-la.com
[email protected]

The following parts can be purchased at digikey.com or mouser.com web site. I am also posting all of the things I have found so far with these TVs.

Here are few possible solutions:

If you have no red light and you have a Megmeet MLT386 power supply, check these parts:

1) Swollen caps on the secondary circuit (may cause the red light blink problem, but also see below).
2) Blown fuse F1 (5A/250V) this is caused by a shorted FET at QA1 (20N60), you may also find that SMT cap CX23 is burned up (.001uf) which is in parallel with diode DA2 which may be damaged/shorted, replace these components.

If the power LED goes from red to green when powered up but no picture, then it might be lost +24VDC from the power supply:

3)Check fuse F2 (3.15A/250V, I put a 5A in), if it is blown, replace FET at QA2A (9N50C), replace QA2 as well (9N50C). Check SMT resistors at R233,R234,R235,R236 (.47 ohm). If open, replace with .1 ohm 1W or 2W resistor (easier to source). Also replace SMT transistor QF1 (2X4 or 2N4401 NPN transistor). And replace diodes at DS2 and DS1 (HER207), DS2 was shorted, DS1 was ok but I replaced it anyway.

I dont know as much about the Megmeet MLT169A, but it has similar problems and similar components.

4) I had to replace all of the capacitors in the secondary circuit (there are six in a 3x3 row marked EC9 (1000uf35V),EC10(1000uf35V),EC14(470uf35V) and EC18,EC19,EC20 (all 1000uf35V).
OK for the Megmeet MLT169A with red flashing LED when turned on I found that IC7 was bad. This is an SMT component on the solder side of the power supply. It is a 4407P (P channel 30V MOSFET). For testing purposes, we jumped across it to feed +5V to the TV permenently instead of allowing +5V to go into standby.

blown resistor (42ohm) replaced this and it imediately blew it clearly shows that there is a short circuit in your tv. if you are a tech person please proceed as follows. 1 isolate power supply from hor.output section. 2 now check power supply section.i.e. switching tran., cap..diode etc. 3 if it becomes ok check power supply output. 4 if output is ok then check hor. output section.i.e. h.out tr.,cap& diode in eht winding. 5 check print near eht. 6 at finally eht. 7 see every thing is normal now. now reconnect power to hor.section. put on tv. good luck.