toshiba 42hp66 bad y-sus board

k1200bmws · Joined: 23 Aug 2009 Posts: 4 Location: Los angeles

I have a toshiba 42hp66. The y-sus board (6871qyh053b) failed and has been replace. On power up the screen went very bright and after 1 or 2 seconds the buffer board( the board between the y-sus and the screen) burned out. I think the replacement y-sus board needs to be adjusted. There are 4 pots on the board. 2 on the "main board" of the y-sus and 1 on each of the daughter boards. Does anyone know what each of the pots are for? Should they all be set to zero on startup and brought out slowly? Is there a test point that I should be measured or calibrated at? Is there a service manual that has this info. I read about R36 should be at –200v +/- 5v. Would like to get this unit operational again. It had a good pic... Thanks Thomas

minnie · Joined: 18 Aug 2005 Posts: 2880 Location: Hell

Sounds like a bad panel. The voltages for VS and VA are on the panel. You changed the Y sustain not the power supply so you wouldn't need to adjust the power supply thus if now the buffer board went, bad panel.

Guest · Posted: Tue Aug 25, 2009 5:17 am Post subject: Toshiba 42HP66 repair manual

Minnie,

Thank you for your response. The Y-sus board could be bad, I do not know, how do I test it? I am reluctant to begin board swapping. I have been surfing the web for a good 42hp66 repair manual that has the testing and proper installation process for the y-sus board, but so far no luck. Do you or anyone out there have a link for this info. Note: "for free". I don't mind paying for hardware but this info must be out there somewhere. Looking at these foruns, I am not the first person with this problem.

Thanks
Mr. R...

gary · Joined: 05 Apr 2005 Posts: 584 Location: MANCHESTER, uk

minnie means a bad plasma display panel and i agree with him, time to buy a new set

k1200bmws · Joined: 23 Aug 2009 Posts: 4 Location: Los angeles

Thank you Gary,

I would like to find a repair manual for this unit (42hp66). It could be the panel or the y sus or the buffer board. There must be a test point for each of these items. Does anyone have a manual or a place i can down load a pdf.

Thanks,
Mr R

minnie · Joined: 18 Aug 2005 Posts: 2880 Location: Hell

Look at the panel, it gives you the voltages and on the sustain boards the connectors tell you the voltage/input. So say the VA voltage is 195 volts the connector on the Y sustain or Z sustain will say Va/Vs and you meter it to see if it is 195 volts.

k1200bmws · Joined: 23 Aug 2009 Posts: 4 Location: Los angeles

Thanks Minnie,

I powered up the unit.

At the Y_sus Board I get:

VA=90 volts DC+/-
VS=600 volts DC+/-
5v=5v
Voltage across Resistor R36 (VY) = 710 volts DC

I read something about R36 needing to be 600 volts +/- 5v

Does this sound correct or are adjustments required? If not, which pots should I be adjusting?

Thanks
Mr. R

Guest · Posted: Wed Aug 26, 2009 10:13 pm Post subject:

You sure VS is 600?

k1200bmws · Joined: 23 Aug 2009 Posts: 4 Location: Los angeles

Thanks Guest,

Clearly I’m the worse tech on the planet, maybe I was just drunk. In either case I retested the unit.

At the Y_sus Board I get:

VA=50 volts DC+/-
VS=175 volts DC+/-
5v=5v
Voltage across Resistor R36 (VY) = 185 volts DC

I have repeated the test several times trough out the day including repeated power on and off’s.

I read something about R36 needing to be 600 volts +/- 5v

Does this sound correct or are adjustments required? If not, which pots should I be adjusting?

Thanks
Mr. R

PS still looking for a repair manual for this unit. (toshiba 42hp66 )