Anyone familiar with the Akai LCD3701AD?

[Spork Schivago]

Re: Anyone familiar with the Akai LCD3701AD?

Okay, I unhooked all the accessory boards (DVD, digital tuner, etc). I double checked all my cables. I hooked up a video source (HDMI), still nothing.

I couldn't find the board with a jumper cable before, so I highly doubt I'll find one now. Akai's website doesn't appear to be any help (ie, not contact information, no technical support, no firmware, etc).

It was around 21$ to purchase the board. I'm thinking of not returning it and trying to modify it. But what do I do? I'm thinking it's a firmware issue, personally. I don't think it's the jumper cables that go to the DIM / GND / BL_O/N jumper. If it was, I should still get sound and I should still get something on the buttons.

Is there a chance another board is damaged, like the T-CON? The PSU has been checked and appears to be providing proper voltage, although the 24VDC was reading around 22VDC. I don't think this would be the issue though.

Should I purchase the parts to make the cable and try to dump the firmware off the bad board? I suspect it's the actual MT8202AG that's bad on the old board. That's the one that holds the firmware. So, even with a cable to download the firmware and upload the firmware, I highly doubt I'll be able to grab it. I could try swapping MT8202AG chips. They're BGA. But it appears the firmware is actually stored on the chip. I guess there's a chance the chip is just the interface to the firmware and the firmware is stored on another chip....but if it is in fact on the MT8202AG, then replacing the chips probably won't work.

I guess it wouldn't hurt to try and "reseat" the old chip. I've never used my BGA rework station before and I'd hate to try on this old board. But perhaps it's just bad solder joints and removing the chip and reballing it would fix the issue? I mean, assuming there's nothing else wrong with the board. There was a bad cap by the analog TV tuner that I replaced with one I pulled off another board. Brown in colour. It was just to see if that fixed the problem. It didn't. Kinda running out of ideas.

What would you do?

[vinceroger69]

Re: Anyone familiar with the Akai LCD3701AD?

Tell the customer you cant locate the correct mainboard and see what they want too do being a older set they maynot bother and give it you for parts etc i tend not to repair many ccfl sets lately as i have about 4 here all working but people prefer led tvs 1080 resolution etc

[Spork Schivago]

Re: Anyone familiar with the Akai LCD3701AD?

Tell the customer you cant locate the correct mainboard and see what they want too do being a older set they maynot bother and give it you for parts etc i tend not to repair many ccfl sets lately as i have about 4 here all working but people prefer led tvs 1080 resolution etc

I'll contact him and see what he says. I really want to try reballing that MT8202AG. It'd be nice of that was the issue, but there's a good chance I'll damage the board in the process. I can run that by him. Maybe he'll say give it a shot.

[Spork Schivago]

Re: Anyone familiar with the Akai LCD3701AD?

On the old board, I was checking the SMD fuses, just for shits and giggles. I noticed something though. Over by the VGA port, there's an L78 and another SMD component, CB216. At first, I thought it was flux, but it appears to be leaking something. I can't tell if it's L78 or CB216.

I wonder if they could be what's wrong with the TV. They're very small.

[Spork Schivago]

Re: Anyone familiar with the Akai LCD3701AD?

The service manual shows the CB216 is a 0.1uF SMD cap that goes to the AVCC line of the MT8293 chip. There's a chip that says:

MT8293AE
0624-AESL
L610052

L78 also appears to go to the AVCC line of the same chip. I can't find a datasheet on the MT8293AE, so I'm not sure what it does. It looks like it might be hooked up to the HDMI port. I wonder if they would prevent the TV from starting. The MT8202AG is what appears to drive the transistor that provides the PS_ON and it's keeping that transistor on, preventing the PS_ON signal from going. When I by the transistor and force the TV on, the back light just kicks on and right back off again.

Any chance one of these bad SMD components might be causing that?

[Spork Schivago]

Re: Anyone familiar with the Akai LCD3701AD?

I got a hold of the doc. He said if I cannot get the TV working, he'll just throw it out and he'll even pay me for the board that I bought that doesn't work in the TV. He said I can do whatever I want to try and get it working. Whether I fix it or not, he'll pay me for my work.

That gives me the okay to try to do some more not so safe ideas. The jumper wires, for instance. Should I try hooking them up on the new board like they're hooked up on the old board? He said the TV was bought in the states....

We don't have any 240V lines in this house. I'd have to run one, we don't have any empty slots in our two panels. So, it'd be hard to power up my BGA rework station right now. I'd need to replace the panel with a bigger panel. We only have 100 amp (maybe 150?) coming into the house. The sub-panel I want to say is a 60-amp and the main panel feeds the sub-panel.