Re: HP no backlight
Here are the pictures that budm requested and with the unit attached to a pc the blue light stays blue but there is no flash of the backlights at all. I am hearing a humming sound on the power board when everything is hooked up. Is this normal? I have to do some reading before I start testing the regulators.
HP no backlight
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Re: HP no backlight
Since the LED is AMBER, then that make sense why the ON_OFF is 0V. If the main board does not sense the video signal from the PC, it will turn off the inverter and the power to the LCD T-CON board. So check the regulators on the main board as suggested by retiredcaps.Leave a comment:
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Re: HP no backlight
BRI is brightness. ON_OFF, then, is your backlight on/off. It is 0V, then the main/logic board is not generating it.
Check the voltage regulators on the main/logic board. My sig file has a how to guide.Leave a comment:
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Re: HP no backlight
On closer look that BRL is actually BRI ON_OFF if that makes any sense??. So is that 1.57v within tolerances for the ON pin? Is the 0V correct for the OFF pin? All others seem OKLeave a comment:
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Re: HP no backlight
The model # is HP-VS17 I will upload pictures in the morning. I have it apart now but I can't be sure if it flashes or not but if it does its quicker than the eye. When plugged in the blue power light comes on than goes to amber. I don;t see any flash of the backlights but I can see the image with a bright light.Leave a comment:
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Re: HP no backlight
ON_OFF = 0V
I'm not 100% sure if BRL is backlight. The "R" is confusing me. Additionally, ON_OFF could be the backlight on/off command.
I define a short as anything less than 30 ohms. AFAIK, there is no industry agreed upon value.Leave a comment:
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Re: HP no backlight
Yes there is as follows BRL ON_OFF, +5 volts, +5 volts, GND, GND, GND, +12 Volts. The voltages on these pins read 1.57v, 0v, 5.22v, 5.22v, 0v, 0v, 0v, 12.24v. You say non of these mosfets are shorted!! what kind of readings would I get if they were? (just learning)Leave a comment:
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Re: HP no backlight
None of those mosfets are shorted.
On the connector to the main/logic board (which is cut off in the picture), is there a legend? If yes, is there a pin that says BL_ON or something. The main board generates the BL_ON and it should be > 2.0V DC.Leave a comment:
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Re: HP no backlight
Thanks retiredcaps assuming pin 1 is indicated with a dimple the readings are as follows
Q 104
S1-G1-30 m ohms
S1- D1- 4 M Ohms
G1-D1- 0L
S2-G2-69 M OHMS
S2-D2-0L
G2-D2-0L
Q105
S1-G1-29 M Ohm
S1-D1- 20 M Ohm
G1-D1- 0L
S2-G2-38 M Ohm
S2- D2-0L
G2-D2-0L
where I get a reading the reading is continually decreasing?Last edited by davg; 11-02-2012, 04:01 PM.Leave a comment:
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Re: HP no backlight
P607 datasheet
http://pdf1.alldatasheet.com/datashe...D/AOP607L.html
Measure to see if S1-G1, S1-D1 and D1-G1 are shorted. Do the same for the "2s" and report your readings.Leave a comment:
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HP no backlight
This is a 19 " HP which powers on OK but the backlights will not light. I tested these lights and they test OK I replaced all the cap on the power board with same results. I am looking at retiredcaps sticky and am thinking that it may be a transistor but I am rather intimidated by these because I am not sure how to identify them for example how can one determine the start/stop transistor? The signalling transistors? etc. This board has quite a number components with the Q designation but look different. Some has E,C,B and some has S,G,D and than there are some with 8 contacts like the 2 (P607 BD5A18)Tags: None
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