Re: Marshall Stanmore Repair
Hey, Arno2. It's a daunting journey, but an enjoyable one and I learned a lot in the process. There are certainly several ways to go about it, too, and you've taken it a step further by trying to isolate the core parts of the existing hardware. I'd actually like to see that work out, but you're correct to point out the challenge of obfuscated design through all that anti-vibration/snooping goop they slopped on the PCB.
In my case, the 50W amp I picked turned out to take a stereo input and split it into two outputs for left...
ToxicGumbo
Member
Last Activity: 11-29-2019, 11:06 AM
Joined: 01-10-2016
Location: Manhattan, KS
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Re: e701i-a3 no picture but backlights
Mine gave out after about a week, though it was due to a panel issue. The initial trauma might have been too much for the remaining drivers to hold up. Most people have had no issues, so I wouldn’t worry about it. There’s no other option aside from junking it.Leave a comment:
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Re: Marshall Stanmore Repair
Please excuse this poor photo, but after scraping off Marshall's glue and rubber absorption material, I believe I found R17, which is labeled "1004".
According to...
[url]https://www.hobby-hour.com/electronics/4-digit-smd-resistors.php[/url]
...and...
[url]http://www.kiloohm.info/smd4-resistor/1004[/url]
1004 = 1MOhmRe: Marshall Stanmore Repair<br /> ...ial, I believe...Leave a comment:
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Re: Marshall Stanmore Repair
Thank you! Much appreciated....Leave a comment:
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Re: Marshall Stanmore Repair
Amazing to see others with R23 problems.
Wiru, here's info for U15 (note that the full 100W isn't directed to any single speaker):
[INDENT]TI TAS5342A 100 watt amplifier
HTSSOP package (44 pin)
Tech sheet: [URL="http://www.ti.com/lit/ds/symlink/tas5342a.pdf"]http://www.ti.com/lit/ds/symlink/tas5342a.pdf[/URL][/INDENT]
Kimera, here's info on Q7:
[INDENT]Fairchild FQPF10N60C MOSFET
TO-220F package
Tech sheet: [URL="http://www.onsemi.com/pub/Collateral/FQP10N60C-D.pdf"]http://www.onsemi.com/pub/Collateral/FQP10N60C-D.pdf[/URL][/INDENT]...Leave a comment:
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Re: Marshall Stanmore Repair
I had no idea anyone had replied to this thread until Kimera wrote me a private message (which triggered an email alert). Very glad to see some activity and people helping each other out. I'll find my board tonight and answer as best I can where questions went unanswered.
As far as my PCB, I never found assistance, gave up on repair, and built an entirely new system using cheap parts over eBay. Here's what I came up with for reference.
It works quite well, but has a very low...Leave a comment:
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Re: Marshall Stanmore Repair
For reference, here are a couple images of my PCB, top & bottom, as I'm viewing and directionally referring to them....Leave a comment:
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Marshall Stanmore Repair
Hey folks.
I've only seen comments on Marshall Stanmore speaker repair through YouTube videos. Perhaps the lack of internet chatter is related to the dual forms of goop Marshal splatters the PCB with to discourage repair attempts. Nevertheless, I'm attempting to repair one.
Some of the problems I've seen with these devices:[LIST=1][*]Power LED, no audio through Bluetooth[*]Power LED, no audio through any source or faint clicking in speakers[*]No power LED, blown fuse[*]No power LED, faint clicking in power supply[/LIST]
1. Seems to most commonly be... -
Re: e701i-a3 no picture but backlights
Just a couple days after posting my repair success, and after watching two feature films all the way through, a friend helped me hang my Vizio on the wall using a typical wall mount. We turned the TV on and I gave him a demo using a Roku via HDMI.
That evening, I sat down to give it another whirl only to discover trouble: No startup logo, only the bluish/black backlight screen I saw before repairing the t-con board and ripping off a side of tabs. After removing the power cord and giving it a cold start, I would get a screen...Leave a comment:
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Re: e701i-a3 no picture but backlights
Someone correct me if these numbers are off, but I would expect to see voltages fairly close to the following (based on previous posts and my own findings, but don't be surprised if yours aren't an identical match even when working):
Silver capacitor: 12-15 V
3R3: 3.3 V
100: 12-13 V
4R7: 1-2 V
MOSFET: (I didn't double check my own readings on this one)
Drain: 15.5 V
Gate: 3.5 V
Source: 0 V
I would only test these with the t-con PCB screwed in place...Leave a comment:
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Re: e701i-a3 no picture but backlights
In the very first post, freakaftr8 declared the "right side" of the LCD panel as the side opposite the tact buttons (menu, input, vol, etc.) and the first corner with the ribbon cable to disconnect being on that same side and behind the printed Vizio name (as seen on the bezel's lower right when viewed from the front). Most people have been referring to it the same way, though there's certainly been a lot of "right" and "left" thrown around based on point-of-view and TV orientation, especially since "right"...Leave a comment:
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Re: e701i-a3 no picture but backlights
One question: When you say the above, do you mean that you're not even seeing the backlight? Does the LCD panel stay dark the entire time as if the TV hasn't even been powered on?
If so, the initial concern is less about the t-con board and more about the LED backlighting or power supply that drives it. It should emit a bluish glow even if the t-con board isn't wired up.
Edit: Okay, technically that was two questions....Last edited by ToxicGumbo; 09-19-2017, 08:22 AM.Leave a comment:
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Re: e701i-a3 no picture but backlights
Pretty uneventful tab-ripping ceremony (thankfully). The TV looks sharp and the wife's happy. An eBay remote clone's on its way in the mail. Thanks, all, for keeping this thread packed full of information and success stories.
First photo: Testing the TV after pulling the tabs
Second: Leftovers
Third: The 70in Vizio in front of a 50in Panasonic plasma TV (a previous repair job)...Leave a comment:
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Re: e701i-a3 no picture but backlights
Progress with my TV. Had to wait about a week for five [URL="http://www.mouser.com/search/ProductDetail.aspx?r=755%2dRTR020N05TL"]RTR020N05TL[/URL] MOSFETs to arrive from Mouser. Shipping doubled the price to about $11 total.
The guy I bought the Vizio from (for $100) had two T-con boards in different states of disrepair, the replacement in worse shape than the original. I replaced the MOSFET on both, but only his original board tested to have the expected voltages.
I removed the flat cable from lower...Leave a comment:
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Re: e701i-a3 no picture but backlights
Easy, now. I'm doing everything by the books and respect all the contributions you've made to help people get there. What I was suggesting is just a poser for conversation. Has anyone investigated the role this transistor plays in the circuit? What's calling it and when?Leave a comment:
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Re: e701i-a3 no picture but backlights
After reading this entire thread, there hasn't been any talk about the transistor's role. Is this MOSFET being used solely as a switch? Can the transistor be entirely eliminated in this circuit and the source and drain jumped with a fuse? As nutty as that sounds, I'm hoping to generate conversation on repair alternatives.
(And with that, I'm off to place an order for MOSFETs to repair two T-con boards.)Leave a comment:
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