Sanyo DP50749 not switching on

[Chuper]

With everything connected when you press power button relay clicks, the green light comes for about 3-4 seconds, relay clicks light goes away, in one second tries again, clicks, green light comes for 3-4 seconds, clicks, light goes away.
At this moment on the PSU BN44-00274A:

Connector CN802 has:
Pin1 - 5.3V - 0V
Pin2 - 5.3V - 0V
Pin3 - GND
Pin4 - GND
Pin5 - PS_ON - 3.058V
Pin6 - VS_ON - 0V

Connector CN801 has:
Pin1 - PS_ON - 3.058V
Pin2 - VS_ON - 0V (no connected wire)
Pin3 - STBY - 5.285V
Pin4 - GND_STBY
Pin5 - GND_15Vmp (no connected wire)
Pin6 - GND_15Vmp
Pin7 - 15Vmp - 0V
Pin8 - 15Vmp - 0V
Pin9 - GND_5.3V (no connected wire)
Pin10 - GND_5.3V
Pin11 - GND_5.3V
Pin12 - GND_5.3V
Pin13 - 5.3V - 0V
Pin14 - 5.3V - 0V
Pin15 - 5.3V - 0V
Pin16 - 5.3V - 0V
Pin17 - GND_15V (no connected wire)
Pin18 - GND_15V (no connected wire)
Pin19 - 15V - 0V (no connected wire)
Pin20 - GND_15V
Pin21 - 15V - 0V (no connected wire)
Pin22 - 15V - 0V
Pin23 - N.C (AC_DET) - 5.266V
Pin24 - N.C (Vt) - (no connected wire)

Visual check gives no burned elements. All fuses are good.
I found a service manual and the procedure of eliminating Main Signal Board. I did that with no luck meaning TV is not generating internal patterns without the Main Signal Board attached. So here during this test relay clicks ones (stays on) and in my understanding the PSU must be on. On three big capacitors CP801, CP802, CP803 I only got 158.2V across them. On the DX807 - 5.285V; on DX806 - 27V(must be 15V I guess), DS801 - 0.2V (must be Va with is 55V), DS825 - 0V (must be Vs wich is 210V).
So the question is should I order a power supply? Or someone on here will help me track the problem down?

[budm]

Re: Sanyo DP50749 not switching on

Does PS-ON Voltage change state when power switch is toggled on and off?
Power supply board is SAMSUNG BN44-00274A.
Most SAMSUNG Plasma power supply uses active low for PS-ON, MEANING <1V = ON, >2V = OFF.
Please upload the service manual.

[Chuper]

Re: Sanyo DP50749 not switching on

PS_ON does change it's value to low 0.022Vdc for those 3-4 seconds.

[dskall]

Re: Sanyo DP50749 not switching on

If you cannot generate test pattern. Most likely power supply. Repair kits available

[dskall]

Re: Sanyo DP50749 not switching on

I have this same TV. I have found the 3.3v regulator is about 2.7v. Ic 1630 P.47 in above SM. I removed it and applied 3.3v externally and tv works. My question. It is a sharp 5 terminal regulator and is a little difficult to find. Can I use a common 3.3v reg. to replace. Or other substitute. I believe one terminal is an enable pin. Not that good with circuits yet.

[budm]

Re: Sanyo DP50749 not switching on

If it is a switched LDO the you will need to replace it with the same type, they put switched LDO due to the circuit is required to be powered up in sequence.

[dskall]

Re: Sanyo DP50749 not switching on

Will keep looking for reg. It did power up from external power

[Chuper]

Re: Sanyo DP50749 not switching on

Ok, took a long time to get it from Korea but in my case ICQ805 (KIA78L15F) voltage regulator quit working. Replaced it and voilà TV is working again.