Thanks! 107 pages of education!
ds2010
Member
Last Activity: 04-26-2024, 04:58 AM
Joined: 10-19-2016
Location: Moscow
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Re: LG 55EC930T - System Menu doesnt initialized
Thanks! 107 pages of education!
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Re: LG 55EC930T - System Menu doesnt initialized
Yeah, the topic starter mentioned that above a couple of times.
My concern is that after "IN STOP"+password, to turn the TV on, the P-ONLY has to be used (topic starter also mentioned that), and I am told that it would reset the usage hours (UTT).
Oh, by the way, will "IN STOP" also reset the panel calibration data? I remember reading somewhere about that, but I might be wrong here....Last edited by ds2010; 10-20-2023, 06:24 AM.Leave a comment:
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Re: LG 55EC930T - System Menu doesnt initialized
Hi Tokenizer (or anyone who can help)
I have a similar issue with [B]"Loading..."[/B] and then [B]"System Manager initialized"[/B]
You mentioned in your last post in this thread that you solved the issue by "successfully resetting to initial via the system menu".
I haven't found the factory reset option in either IN-START or in ADJ service menus.
Can you pls guide me through and elaborate on what exactly you did to perform the factory reset via service menu?...Last edited by ds2010; 10-20-2023, 03:41 AM.Leave a comment:
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Re: Velodyne switching PSU ?
It is 22uF x 25V.
Can I please ask you for the favor in return (or anyone who has an access to this Power Supply board).
Can you please make a photo of the front of capacitor C9 (that blue HV cap) and post it here? It is charcoaled in my unit, and I need to find a replacement, but can't read a marking on it.
Or at least please re-type all text that appears on it.
Thank you....Leave a comment:
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Re: Yamaha Electric Piano CLP550 no keyboard output
Hey [B]dkneyle[/B],
Can I ask you for a favor? Since we don't have pinned headers in the threads on this forum, maybe it would be a good idea if you could edit your very first post in this thread and add a little summary there, stating that (and how) the issue has been resolved and also give the link to the final "tested working" collection of ROM images in my post #114 on page 6 (rar attachment).
For a newcomer (I remember myself when I just came here) it is a bit brain-twisting to find their way...Leave a comment:
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Re: Yamaha Electric Piano CLP550 no keyboard output
Two main factors contribute to why the story is different for PC BIOS:
1) PC BIOS ROMs are 27C256 (32KBytes x 8) , whereas the Clavinova GEW ROMs are 27C040 (512KBytes x 8), meaning their dye cell density is somewhat 16 times higher! Those C040 were clearly pushing the technology at that time (late 80s), so you can indeed expect much lower reliability and retention time from them.
2) It's now been 31 year since my Clavinova was manufactured, and I am still using it. Surely, if you used your PC XT with...Leave a comment:
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Re: Yamaha Electric Piano CLP550 no keyboard output
I think, now, when we figured out the good ROM dumps, the approach should be to replace all three ROMs with the reprogrammed ones anyway (see post #114 on the previous page), first, because that would take away all questions about the integrity of the data in GEW ROMs, and, second, because even if the data in the original ROMs is still good, it can get corrupted any time now, as the chips are well past their data retention period.Leave a comment:
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Re: Yamaha Electric Piano CLP550 no keyboard output
BTW, what model of the CRO/analyzer did you buy?
Is it standalone or PC-based?Leave a comment:
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Re: Yamaha Electric Piano CLP550 no keyboard output
Fair enough.
Good luck and write back here when you have some news for us.Leave a comment:
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Re: Yamaha Electric Piano CLP550 no keyboard output
Hi PMD,
You've suddenly gone quiet after our last exchange.
Does this mean a complete success or complete disaster? :-)
Let us know of you progress, will you pls?Leave a comment:
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Re: Yamaha Electric Piano CLP550 no keyboard output
Hi PMD,
Well done. Here are my 5c worth:
1) 74HC595 is not a TTL. It is CMOS, meaning that it presents virtually no load to the outputs of the driving ICs. So, I wouldn't even bother buffering the CLK and SH0, as the CLK frequency 3MHz is so low (relative to the dynamic capabilities of those ICs). So my first suggestion is to remove your buffer inverter and connect SH0 (pin20/IC12) directly to SER (Pin14/IC98), and connect CLK0 (Pin28/IC12) directly to both SRCLK pins (Pin11/IC98 and Pin11/IC99). You...Leave a comment:
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Re: Yamaha Electric Piano CLP550 no keyboard output
Hi PMD,
Oops, I have already closed back the piano and returned it to the owner, so I can't read out the main ROM. Actually, we don't even know what ROM part is used, as Yamaha gives a cryptic MAIN#2067 name to the main ROM IC. We can only guess by the number of address lines (17: A0 to A16) coming to that chip and by writing on its schematics symbol that it would be 1Mbit ROM (128K x 8) perhaps 27C1001, judging by the pin layout.
If that's true, then it is much smaller transistor density of the dye, and...Leave a comment:
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Re: Yamaha Electric Piano CLP550 no keyboard output
Hey PMD,
As I said, please find attached the waveforms of SH* signals relative to clock and DAC LE (Latch Enable). Some notes:
The clock is 3MHz,
The LE frequency is 200 KHz, pulsewidth is 0.333 uSec (1 clock period)
The SH* pulse frequency is 50KHz, pulsewidth is 1.875uSec (6 clock periods)
The gaps between SH* pulses are 3.125 uSec (10 clock periods).
Look at the waveforms for further info.
NOTE! See the correct sequence of SH* pulses in analyzer channel labels...Last edited by ds2010; 09-20-2019, 04:49 AM.Leave a comment:
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Re: Yamaha Electric Piano CLP550 no keyboard output
PMD,
I will go through my captured analyzer waveforms to see if i can extract the exact timing data for those SH* pulses relative to incoming clock. If I manage to get it out, I will post them here.
I got an impression somehow, that the exact clock position of your missing SH pulse is not that important, as long as it is located between the other two SH pulses with enough gaps, as we discussed above.
What I am coming to is that it should be possible in your case to re-create that missing...Leave a comment:
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Re: Yamaha Electric Piano CLP550 no keyboard output
Hi all,
You wanted another success story? I have one for you!
My Clavinova CLP-550 is working as new again.
I have programmed the blank 27C040 chips (I used OTP versions) with the BIN images attached to this message and it's a goer! Piano works fine!
Thanks so much to all contributors in this thread - without you guys it would have not happened. I guess this is a good example of how the internet has totally changed the living model of the world! Thank you all!
Regarding...Last edited by ds2010; 09-19-2019, 07:29 PM.Leave a comment:
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Re: Yamaha Electric Piano CLP550 no keyboard output
Update.
First and foremost: I have removed and attempted to read out the GEW ROM ICs from my Yamaha. The results are reported further in this post.
In short: I can consistently read IC10 and IC9, but reading IC8 gives different results every time: I've read the IC8 about ten times and all of those ten dumps are different from each other. So, I am concluding that my IC8 readings can not be trusted, possibly for IC8 is damaged (or its internal data is lost).
Second: I think I confused myself...Leave a comment:
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Re: Yamaha Electric Piano CLP550 no keyboard output
Desoldering the ROMs is not a problem - I normally use the hand-held solder suction tool, and it works a charm, it's a nobrainer. But I don't have a programmer, and have to get (or build) one, or at least to build a reader using Arduino or similar Dev tool.
In fact, the funny thing is that I actually do have a programmer, but it can only be connected to a DB25 parallel port of the PC, and I don't have one around! I am hearing that USB-to-Parallel dongles won't work, as the original programmer's software (and drivers, Win...Leave a comment:
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Re: Yamaha Electric Piano CLP550 no keyboard output
Hi, PMD.
I can do that, no problems, but if you are missing only one of the four signals SH0 to SH3 (btw, which one is that you are missing? Is it stuck low or high?), and three other signals are OK, you can easily figure out the missing channel timing. Here's how:
Basically, there is one error in your hand sketch of the waveforms: The time gap between the pulse on SH3 and the SH0 is shown too long. In reality, all pulsewidths for SH0 to SH3 are exactly the same (you call them t2), and all the time gaps...Last edited by ds2010; 09-12-2019, 03:33 AM.Leave a comment:
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Re: Yamaha Electric Piano CLP550 no keyboard output
[B]dkneyle[/B], welcome back to your own topic! :-)))
PMD, thanks for your contribution.
There are two modes I can test my CLP-550 in:
- One is a normal operation,
- Another one is when you put the device in a test mode (A-1 + C7 + PowerOn, refer to the last two pages of the Service Manual), and then, according to SM, you can output the continuous tone, by pressing C0 or D0 or E0 keys (F0 stops the tone).
In my case, I prefer the latter, as it gives me a consistent behavior.
...Leave a comment:
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Re: Yamaha Electric Piano CLP550 no keyboard output
Thanks for your quick reply PMD,
I hope the others will re-join this conversation soon too.
Before I rush onto removing the ROMs, I want to be absolutely sure that it's one (or more) of them who is a culprit.
The symptoms in my case are not a clear cut, to this point - see below.
I do have a CRO, and can probe the signals at multiple points. Of course, I have a schematics.
Here's the brief summary - maybe someone experienced in repairing those beasts can give me their option:...Leave a comment:
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