Re: Hitachi 42HDT52 Plasma TV - HDMI initially has no sound on Power-up
Thanks for your post. I don't have any reason to think there's anything wrong with the main board, other than possibly the version of firmware that's loaded on it.
Unless there's something wrong with the MB that's keeping it from recognizing when a MMC is inserted. At this point I haven't found anything that makes that a strong possibility.
Howard_Woodard
Senior Member
Last Activity: 04-14-2023, 08:45 AM
Joined: 10-30-2013
Location: Redmond, WA
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Re: Hitachi 42HDT52 Plasma TV - HDMI initially has no sound on Power-up
It would be interesting to be able to get some sort of confirmation that the file they sent me is even the correct fw for my TV.
Looks like this is kinda dead ending…Leave a comment:
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Re: Hitachi 42HDT52 Plasma TV - HDMI initially has no sound on Power-up
Thanks. I've tried 9-pin SD card and the older 7-pin MMC card. The card is inserted with the notch down (only way it will latch in and the way the update instructions show). I've not seen any indication that the card is being detected.
What is the make/type and size of your card that's being detected?Leave a comment:
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Re: Hitachi 42HDT52 Plasma TV - HDMI initially has no sound on Power-up
So, you are using a 7-pin MMC that is formatted FAT, not a 9-pin SD using FAT32?
And you had the file DW1UC105.E06 as the only file on it?
Interesting because I get no indication whatsoever that it is recognizing my KingMax 256mb MMC card -- file or no file.
My firmware version is V0110.0001. What is yours?
I'm attaching a picture of my setup screen....Leave a comment:
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Re: Hitachi 42HDT52 Plasma TV - HDMI initially has no sound on Power-up
Dang, I don't have access to the TV very often and I try different variations of card/format/file, etc each time but I keep forgetting to write the current fw version down. I'll get it but for now I can say that [I think] the version number shown on the TV bears no similarity to the file name that was sent me - but I could be wrong. I will see if I can keep my nub of a brain engaged enough to get the fw vers shown on the TV sometime this weekend.
The 7-pin MMC card is formatted for FAT32 and has...Last edited by Howard_Woodard; 05-27-2021, 11:35 AM.Leave a comment:
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Re: Hitachi 42HDT52 Plasma TV - HDMI initially has no sound on Power-up
I am unable to find a Hitachi web site with any support files, firmware, manuals, etc. but after contacting Hitachi Customer Service by email, I got the following reply:
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[I]"Hello and thank you for contacting Hitachi,
Please see firmware update .zip file and instructions on how to proceed attached below. Keep in mind that the firmware needs to be placed on an SD card no greater than 1Gb in size, otherwise the TV may not recognize...Last edited by Howard_Woodard; 05-25-2021, 07:19 PM.Leave a comment:
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Re: Hitachi 42HDT52 Plasma TV - HDMI initially has no sound on Power-up
Thanks. I'll have to check that the next time I'm at my SiL's house. In the meantime, I've looked for a Hitachi support site to see what downloads are available and don't find one.Leave a comment:
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Hitachi 42HDT52 Plasma TV - HDMI initially has no sound on Power-up
Hi all. Up until 3 years ago I used component video as the connection between my Comcast cable box and this TV and never had any issues with it -- it always worked perfectly. Then I upgraded my cable service and the new box had only an HDMI connection. The Comcast remote controls both the cable box and the TV. About 50% of the time, when I would first turn the TV on I would get video but no sound. After trying new cables, a new cable box, and switching between the two HDMI ports had made no difference, I changed the video source to see if that made any difference. It did not but I did notice that... -
Re: Samsung 32 inch (LN32B360C5D) in perpetual restart loop...
Ha ha. No scopes or other electrical components - or engineers - were hurt in this effort. You're the second to offer such a warning on this thread. I guess I might have assumed too much -- I assumed that anyone using a forum called "badcaps" working on an open TV set was probably knowledgeable enough to understand how power supplies, including switchers and their grounds, work and especially how to use oscilloscopes.
At any rate, I guess it's a good warning for those that aren't competent -- assuming...Leave a comment:
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Re: Samsung 32 inch (LN32B360C5D) in perpetual restart loop...
Just a final update in case others might have similar symptoms...
After being off for a couple days it came up and acted correctly as it has done before. But rather than turning it off, which has always caused it to resume the endless looping, I updated the firmware. After successful completion of the update the TV has worked perfectly ever since -- no looping or any other unexpected behavior.Leave a comment:
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Re: Samsung 32 inch (LN32B360C5D) in perpetual restart loop...
Yes, I understand the difference between power ground and signal ground -- my scope connections are correct and the readings are correct. I have it plugged into a GFI outlet and have popped it a few times when I had one probe on the hot side and tried to simultaneously monitor a point on the cold side. Ha ha, it probably thought the difference in current between L1 and N was flowing through my heart.
Btw, the heat sinks inside the "hot line" on the PCB are part of power ground. But the negative...Leave a comment:
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Re: Samsung 32 inch (LN32B360C5D) in perpetual restart loop...
In the pictures attached, the yellow trace is UP801S pin 1, the blue trace is pin 4 and the purple trace is pin 7 at the gate of QP802S.
When working correctly or while in the boot-loop the voltage across CP815 is a clean 379vdc.
Pin 1 stays around 2.88v-3.5v when it the TV is working correctly as well as some of the time when it was boot-looping. It also got as high as 8v.
I've seen pin 4 creep above the .8vdc that triggers an over-current condition only when it is rebooting. When...Last edited by Howard_Woodard; 01-11-2020, 10:55 PM.Leave a comment:
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Re: Samsung 32 inch (LN32B360C5D) in perpetual restart loop...
Ha ha. I'll have to wait until it fails to see what UP801S looks like when it is looping. When I first plugged the TV in it was looping and I clearly had two different signals going into pins 1 & 4. But every since then the set has worked perfectly.
I did notice that the voltage on pin 4 of UP801S is between 600-700 mv. The data sheet says that 800 mv it will trigger an over-current. Pretty close...Last edited by Howard_Woodard; 01-11-2020, 08:06 PM.Leave a comment:
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Re: Samsung 32 inch (LN32B360C5D) in perpetual restart loop...
Btw, when I first turned it on this morning it rebooted one time and then stayed up -- no auto-rebooting -- and everything worked like you would expect. I left it on and came back to it in about an hour and it had shut itself down -- and stayed down. When I turned it on it went into boot-loop and has been in that mode every since. Whatever it is, its not a hard failure. It would be interesting to know what the mainboard is doing, or waiting to do, in that 28-30 second period after the start-up chimes sound. The on/off...Last edited by Howard_Woodard; 01-11-2020, 05:19 PM.Leave a comment:
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Re: Samsung 32 inch (LN32B360C5D) in perpetual restart loop...
Ok, just got back home and looked to confirm what I had done before responding to you.
(1) Inverter On/Off (pin 12) is grounded to signal (cold) ground on the PSU side.
(2) DET_5V wire between PSU and main board is cut. PSU side left to float and mainboard side pulled up to 5v.
Get no backlight [as expected] but the TV goes into it's boot-loop mode.Last edited by Howard_Woodard; 01-11-2020, 04:09 PM.Leave a comment:
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Re: Samsung 32 inch (LN32B360C5D) in perpetual restart loop...
Yes, I did -- thanks for the link. Still pretty skimpy on mainboard info.
My wife sent me on a grocery errand. I'll follow-up on this when I get home.Leave a comment:
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Re: Samsung 32 inch (LN32B360C5D) in perpetual restart loop...
Hi again Bud. I put a 1K pull-up to the 5V rail (pin 2) on the DET_5V line (pin 14). It still loops. On the scope it goes to 5V at about the same time that the BL comes on. Then, at approx 28 seconds, as always, you see a momentary "tick" on the line before it drops to 2.8v (the pull-up value) and then re-boots and continues that regular looping.Leave a comment:
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Re: Samsung 32 inch (LN32B360C5D) in perpetual restart loop...
Interesting. I think I read that one of the purposes of the DET_5V error line was to shut down the PSU if over-current conditions were detected in the inverter an/or CCFL bulbs. How would you know whether a problem is the inverter or one or more of the bulbs?Leave a comment:
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Re: Samsung 32 inch (LN32B360C5D) in perpetual restart loop...
Got it - thanks.
Btw, is there any problem disconnecting the PSU from the CCFL sockets and powering it back up?Leave a comment:
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Re: Samsung 32 inch (LN32B360C5D) in perpetual restart loop...
Thanks. I'll fiddle with what the DET_5V signal is telling me and where its coming from tomorrow.Leave a comment:
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