HP ZR2440W displays 'something'

[bokkie]

Backlight seems ok
12v measures 11.8v
5v measures 5.17v

place of the "menu" is correct but not showing menu, just garbage "pixels" (ascii "art")
if input is present, video is also same kind of ascii garbage

could use some pointers in what direction to look further

-have not yet de-soldered that ton of caps on the mainboard
-checked the memory bga (broken contacts)

[bokkie]

Re: HP ZR2440W displays 'something'

sooooo ... decided to dig out the shelf-project again
all caps are measured and ok

seeing that it does display the correct placement of the supposed menu and if i get into the menu one can even guess what line it's at
i'd guess the T-con is ok and the problem is on the mainboard

it tries to display both menu and input but only 'garbage' pixel-info exits the board.
can't find a servicemanual and digital is a bit out of my league ..

any pointers as to how and where to look are appreciated (don't have a logic-analyzer or anything fancy but a scope (a few actually) i got)

[petehall347]

Re: HP ZR2440W displays 'something'

i expect poor data line connections can do this sort of thing ..garbage in garbage out . some tcons have self test onboard . out of my knowledge really .

[bokkie]

Re: HP ZR2440W displays 'something'

forgot to mention, the white(-ish) background is when signal/input is present
no incoming = black background ..

I'll try to read up on digital signal pathway .. if i can find the time (and willingness)
there is a reason that thing was shelved for months

i understand no-one here has a crystall ball (hell, mine is broken too most of the time) ..just looking for pointers (or disproving of my thoughts) if anyone kinda recognizes the symptoms or has more knowledge ..

yes petehall347, something in the lines of datacorruption, since input AND menu are gabled I think (out loud) i should start looking between t-con and that main chip

need to read up howto/what-to measure (what kind of signal .. dmm/scope ?!)

display is LM240WU8-SLA1, got the sheet for that
so at least i know what should go where ..