UMC L22/01C No backlights (B/L ON voltage)

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Hi

Got this UMC and the backlights are not starting, all voltages seem correct apart from BL ON

These are the voltages on the inverter board

Standby:-

Vcc=12.20v
Vcc=12.20v
ON/OFF=0.08v
ADJ=0.00v

Powering Up:-

Vcc=12.03v
Vcc=12.03v
ON/OFF=0.08v
ADJ=0.00v

On:-

Vcc=11.91v
Vcc=11.91v
ON/OFF=0.08v
ADJ=0.00v

I have attached pictures of the main and the inverter, I have not attached PSU as its an external jobby

Could I add that apparantly if you sit there for 10minutes and keep disconnecting and powering up the tv it will work..I am guessing that it finally throws something down B/L ON for the odd start up

On the main my only concerns is the 8 legged ic to the lower right of the largest IC,with the black heat sink on top...but I cannot read the back of the thing at all, and no schema's found to cross reference

Any help would be appreciated

Sorry about the chip pic's I keep getting flash glare will post more in the morning under natural light

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Re: UMC L22/01C No backlights (B/L ON voltage)

This is a bit better pic of the ic in question

[budm]

Re: UMC L22/01C No backlights (B/L ON voltage)

I see some 3-leg LDO regulators on that main board. How are the voltages on those regulators?

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Re: UMC L22/01C No backlights (B/L ON voltage)

Here you go

[tom66]

Re: UMC L22/01C No backlights (B/L ON voltage)

In standby?
Now try with TV not working, then after 10 mins fiddling, TV working. We need both states.

[signup]

Re: UMC L22/01C No backlights (B/L ON voltage)

I will try but have spent sometime getting the dam thing to start with no success

The picture on the right is with the tv on but not working

[martyparish]

Re: UMC L22/01C No backlights (B/L ON voltage)

Possibly get it started by heating with a hair dryer. It's worked for me and is suggested on these boards often.

[4cc3ss]

Re: UMC L22/01C No backlights (B/L ON voltage)

Is there Vcc present across C1 & C2, component T is an internal fuse.