dkneyle
Badcaps Veteran
Last Activity: 01-03-2026, 09:33 PM
Joined: 12-16-2013
Location: Tathra, New South Wales
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So pleased to hear of your success! I was the one that initiated this quest to recover the ROM code, and through the efforts of different people, that was achieved. Makes me a very happy fixer-upper when I hear of success stories like yours. -
Yes, disconnected those two LVDS and the power supply came to life. The Optic Audio port didn't actually light up, but I had 20V output and everything you'd expect from a working power supply. Upon very close inspection I found a crack in the plastic front cover, about 5cm long, not far from the edge of the frame. I'm pretty sure that the point of disaster. I've advised the owner it's a write off, and I'll salvage the good boards. Do you reckon the T-Con would be damaged or OK?...Leave a comment:
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Thanks for that good advice. I'll try and advise outcome....Leave a comment:
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I'll look very closely again. I assume if the oled panel is damaged then the self check routine identifies that and won't start the power supply?...Leave a comment:
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LG LGP65C2-220P Bitten by a cat!
I have been passed this OLED TV which has an interesting story. The owner's cat was seen to bite the edge of the panel at which time the TV shut down and won't restart.
I can see no physical damage to the panel. I don't know OLED technology, but I'm assuming that the cat's bite caused some elements in the panel to come together, which normally should never come into contact? The bite would be on the edge of the panel where the connections are.
I've tested the power supply. When the Power On button is pressed it flashes off then back to red state. The Power On line... -
As the bloke that started all this MANY years ago, I'm so glad to learn that people are having success! BTW, I had cause to talk to Yamaha Australia about another keyboard I recently (successfully) repaired, and told the tech about what we'd achieved with getting old Clavinovas going . I told him we'd extracted the code and it was now out there in the public domain. He didn't seem the least concerned. But you may recall, Yamaha refused to give or sell me the code; they wanted ~$300 for the three ROMS....Leave a comment:
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Firmware refuses to load up. I communicated with the guy that sold me the mainboard. Bear in mind, the TV is 46 inch, the board came from a 55 inch TV. But they are use same mainboard. Seller says the TCON has a firmware in it as well, which knows the mainboard is not correct for size of TV, hence why it wants the firmware upgraded. Given the mainboard had failed, I'm wondering if the T-Con was also damaged and might be preventing the firmware upgrade?
I've not had any experience with this nonsense of Smart TVs and the need for firmware upgrades. Anyone want to offer their thoughts...Leave a comment:
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Why do you say MBR Mode? I've formatted as FAT32 and FAT16; still can't get the firmware to load....Leave a comment:
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Sony KDL-46HX850 Can't upgrade/update firmware
Diagnosed this TV as having a failed main board which I've replaced with one from a KDL 55HX850. They are (supposedly) the same board.
Being 'Smart TV' it requires a firmware reboot when you swap out boards such as T-Con or main board. It starts with a black screen and flashing yellow and green LEDS, indicating it needs that firmware boot. The procedure described all over the web is to put the software into the root directory of a FAT32 formatted USB drive and it should load that up once plugged into USB1 port. But not for me. I can see the LED on the USB chip flash for about... -
Dagav, if your LED tester says the panel LEDs are busted, then what is the point of going further? Those testers are pretty good at firing the LED string if there's nothing wrong with them. From what you have described, I'd certainly also suspect a failed mainboard if you aren't getting any turn backlight on voltage signal. I assume you have +5v standby supply?...Leave a comment:
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Re: GP0812LD SMPS IC possible substitute?
My man, Larry, ran the local electronics repair shop until it became uneconomical to do so any longer. So he recently joined our team and we are the only service available to people to get their stuff repaired.
Larry knows repairs better than me because he's had more recent practise doing so. But as you well know, when a SMPS has stopped it can be difficult to track down why because of the feedback circuit. But I'll pass all this onto Larry and let you know how we go.
Cheers, DLeave a comment:
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Re: GP0812LD SMPS IC possible substitute?
Hi RJ,
The SMPS is in at the Repair Cafe - a volunteer organisation that only operates on Fridays. (And actually, we are closed this coming Friday- so it will be the following Friday before we get back to it again.)
My plan was to photograph it and get those images through to you.
Obviously a datasheet would be helpful if we knew what the IC really is?
I'm also going to get my colleague who is doing the actual work to look and see if it might be a bad cap? Usually, if the controller...Leave a comment:
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Re: GP0812LD SMPS IC possible substitute?
I reckon you are right about it being an in-house ic number. I too could only find a Chinese site where someone was also trying to identify it.
Can't tell output voltage as non functioning.
Will get those images through to you,Leave a comment:
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GP0812LD SMPS IC possible substitute?
We are fixing a panel heater with a SMPS, and the switching IC appears to have failed. 8-pin DIP. Type GP0812LD with a manufacturing logo that means nothing to me.
Can't find anything on the net about it. Does anyone here have any knowledge of it?? -
Re: MK1210 chip SMPS based supply - can I fire this up?
Well, disregard most of what I said in Post #18. After quite a few hours of heat soaking the problem returned. Some careful application of heat from a hairdryer and cooling with freezing spray would seem to indicate R33 (which coincidentally in 33 ohms) is the culprit. It actually reads as 27.5 ohms, which is outside the expected 5% tolerance. When I can get my hands on a proper high wattage resistor I'll change it out and confirm if it the source of the problem. Interestingly, it is connected to D23, which was the original...Leave a comment:
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Re: MK1210 chip SMPS based supply - can I fire this up?
The Onkyo laser player bounced. Loss of audio after about 15 minutes. I think I’ve repaired that, and I’ll detail it here, because it might help others fixing these with similar issue.
It was obviously a heat sensitive issue. When I ran without the cover, I couldn’t get it to fail. Using a hairdryer as a heat source applied to various sections I was able to track it back to the power supply. Using freezer spray seemed to indicate it was in the vicinity of the 4 motor drive power transistors, although...Leave a comment:
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Re: MK1210 chip SMPS based supply - can I fire this up?
I’ve continued to watch YouTube videos where VFDs have failed in different types of HiFi gear. They always seem to use a very similar circuit, and referring to the VFD Manufacturer recommended circuit it appears they have all adopted it.
There is an electrolytic cap connected to ground after the resistor in question. If it develops poor ESR then excess current flows through the resistor and it fails. Nearly always the solution in every case I’ve watched is this resistor with a value of about 50 ohms....Leave a comment:
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Re: MK1210 chip SMPS based supply - can I fire this up?
Yep, all other components downstream were checked. As a matter of course I changed out all the electro caps on the secondary and primary side (except main charge caps) to ensure longevity and upped the voltage where that meant the cap could still physically fit.
I sometimes wonder about designers of circuits? Do they just go looking through catalogues and find some exotic component and decide "I'll give that a go". You confirmed what I thought: most fast recovery diodes should do the job. This designer has used...Leave a comment:
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Re: MK1210 chip SMPS based supply - can I fire this up?
Well, I should have listened to Momaka's advice a bit more closely about VFDs.
A VERY expensive lesson learned, after importing a replacement front panel at extraordinary shipping cost from USA and currency conversion. There was no change with the replacement panel so I had to go back to analysing what could be going on. I knew next to nothing about VFDs and assumed they were driven by high voltage AC. WRONG. It's only about 10volts to the filaments, and even though it was high frequency AC in this case I was able to...Leave a comment:
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Re: Weltron 2007 UFO (vintage) - setting bias and crossover
Got DC offset adjusted without too much drama. Vcc is 42 volts, and was able to adjust the offset to 21 volts as per Redwire's instructions. (It was about 18 volts on both channels prior to adjustment).
Bias I couldn't get anywhere near Redwire's calculated numbers. At maximum adjustment I was getting just a fraction over 4mA. Mid point on pot was about 2mA and that was approximately where the pots had been set. So I decided to adjust bias for 2mA because that intuitively seemed about right.Leave a comment:
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