Inverter INVC551 Hitachi in ACER FP855 / COMPAQ TFT8820

ob38 · Guest

Hi, i'm searching for INVERTER Schematic (HITACHI INVC551) present in ACER FP855 and COMPAQ TFT8820, because i have failure in this backlight card.
This card has a failure watch dog, and as soon has the CCFL has a problem, the inverter stops the backlight, causing very hard to find where the problem comes from.

Please help me, i just download the documentations but the inverter is not present inside.

I trust in this forum

Thanks in advance

(Sorry for bad english, i'm french)
Olivier

guest · Guest

Hi,

I have some information regarding your problem, can you mail me on [email protected]

Scotty2k · Guest

Does anyone have this shematics.. i´m searching for it the hole day Sad

ob38 · Guest

Guest · Posted: Thu Mar 02, 2006 2:08 am Post subject: power board

anyone willing to sell there power board? email me at [email protected]

Wim · Guest

Hi All,

I was looking for information on this inverter also. It is used in several types of TFTs: COMPAQ TFT8020, ACER FP855, IBM 9794-AG1,
ViewSonic VG181 and VP181. You can get a new one for $100.
I had TWO failing inverters in one week and did some reverse engineering. The problem with both of them was the same: the ceramic resonator that drives the CPU was fried. The CPU is IC1 (HD404344).
Disconnect the powerplug from the inverter and measure resistance across the oscillator pins (pin 9 and 10 on the CPU), if it's below 600 Kohm, then you have found the problem. I measured about 300 ohm. Replace the oscillator by a new 3pin 4Mhz ceramic resonator.

Bye,
Wim Huiskamp