CurtPalme.com Home Theater Forum

HD-DAVE · Joined: 16 Feb 2007 Posts: 223 Location: Delta, BC

Have access to an free Hitachi 50V500A, 50"'er, (LCD Rear Proj 720P/1080i )....it lights up, but the video processing appears to be shot - I can switch inputs but no signal is displayed other than it cycling thru differnent coloured rasters. Eg one input might show all green, switch to the next and its all red, then the next might be red but 4:3. Anyone come across one of these with similar symptoms ?

I tried "Input + Power" to try to get into the service menu but no text comes up.

Reading up on google tells me Hitachi faced lawsuits over light engine problems with these sets...but I think with a cooling upgrade ( bigger fan or larger duct or ? ) I could get some years out of it once fixed.

Cheers
....Dave

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

HD-DAVE · Joined: 16 Feb 2007 Posts: 223 Location: Delta, BC

Thanks for responding Mac! ...I knew you'd be the first Smile

. Going to take the truck to work tomorrow and snag this puppy...and check those connections! Looks like something that could work itself lose from the set being moved around (or serviced by monkeys).

Thanks!

**Curt Palme** · Posted: Thu Oct 08, 2009 5:03 pm Post subject:

If that's not it, I might be interested in taking a crack at it.

HD-DAVE · Joined: 16 Feb 2007 Posts: 223 Location: Delta, BC

Hey Mac,
Got it home and pulled the lower back cover off the set, checked the main PS LED's - all solid GREEN, main power LED solid RED. F904 intact. Ok, then pulled the metal cover exposing the ECD connector and it looks fine...fully seated at both ends.

That whopping big ribbon cable between the Light Engine and the main Signal PCB scares me...why do they have to use those things...they are so fragile and re & re'ing them could easily damage them or lead to intermittants. This isn't a laptop or something where space is an issue! ... Thats the biggest ribbon I've ever encountered !!! aCCKKK.

I did notice that this set may have been worked on in the past - there was a missing screw on the ballast board, plus fingerprints on the hot air outlet duct. Probably just a ballast change. Appears to have its original LC37E light engine.

I have downloaded the service manual and have been going over it. Not much troubleshooting help other than "dead set, no raster" unfortunately. Might try reseating some boards and see if that changes anything.

Any other ideas, MacGyver ?
...Dave

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

Well it looks like we have a couple things to think about, especially if someone else has been in there. I'll start with the easiest.

First a question. Is there sound? And is the lamp on? I assume its on since you said the screen changes color but just want to verify.

HD-DAVE · Joined: 16 Feb 2007 Posts: 223 Location: Delta, BC

Yes, there is sound and the lamp is on. I can't detect anything messed with other than possibly the ballast board...although even it seems to have about the same amount of dust buildup as everything else in the works...although now that I look closely the light engine seems pretty clean. Perhaps it was changed.

Dave

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

Well having the wrong light engine installed could cause a problem. The 500 and the 500A take different light engines even though they look the same. The part number for yours should be UX22202D (New) and UX22202DR (Rebuilt). Check that and if its ok I have more for you..... Smile

HD-DAVE · Joined: 16 Feb 2007 Posts: 223 Location: Delta, BC

I looked everywhere on and around the light engine in my set but I cannot find any stickers with the UX22202D or DR part numbers. Maybe it is hidden under the perforated metal enclosed circuit boards that mount above the light engine. Whatever the case, its a '500A, and the light engine has the sticker "LC37E" on it (I realize this is the chassis number, and it is the correct one). I am now pretty convinced this set has its' original light engine, however it has probably recieved a new Lamp, as there are chew marks on the screw on the lamp access cover on the front panel. Curiously, according to the service manual addendum i have the Light engine part no. is UE22333(E).

Dave

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

The UE is the main chassis number.

Next thing is your going to have to double check that nice big ribbon cable. It is imperative that the connector is snapped correctly. I have seen seasoned techs have trouble with those connectors. The key that I have found is with the connector unsnapped, carefully insert the cable squarely and completely. Then while holding steady, flip the bar down. It SHOULD CLOSE SMOOTHLY AND FEEL A SLIGHT SNAP.

Make sure it looks correct by the pics I attached. I attached 1 pic that shows incorrect as I know you can tell. I'll continue to post other possibilities.

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

One more thing you can check that is considered a minor repair. It would be an open LY13 that should be on the terminal board. This is in a 9v feed line. Its blue in color.

And if thats not it then you probably have a bad flex converter. If you end up having to take this route post back and I'll give you the correct part number for a replacement.

HD-DAVE · Joined: 16 Feb 2007 Posts: 223 Location: Delta, BC

Thanks MacGyver! I have previously taken a close look at the "ribbon cable from hell" and it appeared seated and locked correctly at both ends but I will double check. The LY13 part you suggested me to check sounds more like it could be a culprit so I will be all over that: If LY13 is gone the main video/chroma/component video switch ( IY04 , a TA1383F chip) would be dead which could lead to the total loss of video sent to the LCD's - which is exactly what appears to be happening. Somewhere in the video chain the signal is being cut off.
Dave

**Curt Palme** · Posted: Tue Oct 13, 2009 3:59 pm Post subject:

Reseat all ribbons cables anyways. Oxidation is common, even if the connection looks solid.

Why am I giving repair advice for this one? I want it ! Very Happy

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

HD-DAVE · Joined: 16 Feb 2007 Posts: 223 Location: Delta, BC

Curt, here's a free widescreen rear projection set for you ...or possibly TWO?!...the set in the pic looks to me like a nice JVC I'Art PRO 48" CRT-based unit. If so these were high end for their day ( 2002 ? ...does 1080i over DVI, with 3D comb filter, built-in scaler, etc).

http://vancouver.en.craigslist.ca/bnc/zip/1411445846.html

...Dave

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

I for sure would have picked that up already...... Very Happy

HD-DAVE · Joined: 16 Feb 2007 Posts: 223 Location: Delta, BC

Had more diagnostic time today: LY13 on the terminal board checked OK, as did all the other blue inductors. I also checked all the inductors on the control board and all were ok. Also reseated the terminal board and all wiring connections to the control board, including the big ribbon, and the connections at the Light engine. No change in symptoms whatsoever...

Time to pull out my ESR tester perhaps, unless you have more things to check, Mac ?

Thanks,
Dave

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

Its kinda looking like the flex converter but this would be a swap and try test.... Crying or Very sad

HD-DAVE · Joined: 16 Feb 2007 Posts: 223 Location: Delta, BC

Hey Mac, What leads you to believe its the Flex Converter ( FC4 board) ? ( past history of repairs ?)

Before I run of to ebay and buy the lone FC board there for $69.99, I first should check what's coming off the signal pcb with an O-Scope ( IE I want to see if I am getting any real external source or tuner video on that 50 pin ribbon connector - pins 27 /28 / 29 / 31 /32 show the Main Y/Pb/Pr + H and V sync... plus SUB video on higher numbered pins...). If its there then yeah the flex converter might be bad...

Well I just noticed something missing from my PDF of the service manual.... there is no Schematic or Circuit board layout for the Flex converter... is this some proprietary exclusion thing by Hitachi ? Shocked

The plot thickens...

...Dave

macgyver655 · Joined: 22 Aug 2007 Posts: 8508

I have direct access to Hitachi service. All the info i gave you is directly from there. I post it vaguely because this info is not suppose to be given out. Flex converter was a common failure and would produce the symptoms you describe. But this is also why I said you wont know for sure without replacement. It may not be it. Its mostly a process of elimination at this point. Let me look at the training manual and see what it has to say...

A lot of manufacturers are not producing schematics for some boards. Its really pissing off a lot of techs. Let me see how large the service manual is from Hitachi. With my air card I'm limited on my monthly total downloads and I dont want to go over as is costs more. I'll do some more digging but I pretty much went through everything already.