I need diagram circuit of bdpc400-ar

There is no fault if you are measuring the voltage with no load.

About the best I can do for you is to point to several resources where you might pursue parts. Can't hurt to try Lenze support: https://www.lenze.com/en-us/support/

But first here is a possible source of daigrams but I am not overly optimistic as it is likely proprietary information: https://www.datasheetarchive.com/Service%20Manual%20Lenze%208200%20vector-datasheet.html

https://www.academia.edu/35233487/Parametros_Variador_Lenze

Teamequip.com might have the inverter control. Here is one link to their webpage, although not exactly to the item number you list: https://teamequip.com/lenze-e82ev222_4c-8200-vector-inverter-control/

I can see why you would be interested in a repair: https://www.amazon.com/Genuine-Lenze-INVERTER-E82EV752K4C200-E82EV752_4C200/dp/B07VB6DXLB

https://www.euautomation.com/en/lenze/drives/e82ev7524c200

https://www.ebay.com/itm/115056566261

Below suggests they do repairs: https://www.radwell.com/en-US/Buy/LENZE/LENZE/E82EV752-4C200/

I doubt you need this operating manual: https://download.lenze.com/TD/E82EV__8200%20vector%200.25-90kW__v3-0__EN.pdf

Sorry, this is as much as I can find that might be of interest.

Back - light problem. Check and replace damaged component/s at its back-light inverter board, or replace this board as card basis. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts. It will be best to replace the inverter board as card basis.
http://electronicshelponline.blogspot.com/
In some models of LCD TVS; the backlight inverter and its T'Con board will be a part of the panel itself, and will be a built-in type inside the LCD panel. If so, they can't be replaced. In this case; a panel replacement is the only repair. For some other models, the backlight inverter section circuit will be a part of the main power supply regulator [SMPS]. To such sets, the power supply section circuit too should trouble shoot. Contact any service technician. The circuit will differ with models and versions.
Just understand; usually circuit diagram to Philips brand devices will be much complicated than other brand devices. So; you should have skill to locate the faulty section circuit.
I advice you to contact any service technician; or the authorized service center for Philips in this case. Surely you will feel some difficult to go with this set's repair.
Type in the brand name and type of your device, in the search box [at the top right] of the display window; to gather down all the posts related to your device brand. It will make surf easy.

Yes

Proprietary info. Good luck on that

copy lamp disconnection trouble - copy lamp or cpy lamp drive circuit (inverter PWB) trouble copy lamp disconnection. If lamp does not light when you power up machine, the lamp is burned out or board is bad.

Please click the link below for a easy type circuit. low cost for your need.

http://circuitdiagram.net/inverter-12v-dc-to-240v-dc.html

only cos your a bmw driver ok? and i feel sorry for you,,, now go to http:/wwwmaxbmwmotorcycles.com
there you will find all the tecnical photos you could ever need on any bmw bike you could think of some may still run on steem?
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how i can joint 4switch box to one lamp with inverter & main

repairing lcd inverter is like repairing a hv circuit used for strobe lights. try to check first all electrolytic capacitors, then loose board solder, also occularly check both ccfl bulbs for breakage and burnt marks.. best is if you can download schematic diagram for it so that you may check also all semiconductors on the board.