Anritsu spectrum analyzer MS2661 tears

[Daxxin]

hi , i am in trouble with this instrument , it power on i hear relays clicking but nothing on display , in stand-by mode since
the problem begin its noisy ..whistling opening the psu have child board with red led (V12 label) flashing fast , dont have
the schematic to test voltages on board no silkscreen labels  , if someone expert anritsu can help me , thanks.

[tautech]

CRT display?

How is the CRT HV derived? From a SMPS? Maybe that has failed?

Hold a scope probe close to the SMPS and see if there is any EMI that indicates it might be working.

[Daxxin]

this model have lcd screen NEC NL3224AC35-01 model

[Daxxin]

I HEARD ABOUT BACKLIGHT ..IF ITS BROKEN THE DISPLAY REMAIN TOTALLY DARK OR CAN VIEW EVEN DARK?

[tautech]

Try shining a bright light directly at the LCD and if you can see a faint image the backlight only has failed.
Some have simple inverters for the backlight HV, others more complex controllers with auto shutdown in fault conditions.
Again you can use a scope probe like a near field probe to see if the backlight oscillator is working.

[Daxxin]

HV is present , touching with fingers the output of 2 coils i see sparkling , so you thing ccfl lamp is gone? anyway lighting the panel cant view anything

[KJDS]

Somewhere inside will be a set of test points to measure the power supply voltages. Check these first.

[Daxxin]

lcd display with his integrated contoller and hv modules get power suppy and signals  form the control panel trough flat cable
FP has test point all 4 values are ok , +14v , -14v , +5v and 12v , , what i found not correct is the Vcc of some ICs on lcd controller
example  TA8696 toshiba controller from datasheet minimal vcc is 4v but i can measure only 1,98v

[KJDS]

Is something on that 4V rail getting hot?

[Daxxin]

None its all fine i found the problem , the bulb ccfl was cracked , alredy ordered the replacement , thanks for the help