I just picked up this MSI Optix MAG271C curved monitor. It powers on, backlight comes on and it's recognized by Windows--even as far as to be able to use the speaker port for music. It recognizes input changes, and goes into standby as intended when disconnected.
But it has no image whatsoever. On power-up it goes through what should be an "MSI" splash screen, but no image, and when hooked up as a secondary monitor I can drag items across my extended display with no change as it reaches the blank monitor.
Does this sound like behavior that can be...
DoorOfTime
Member
Last Activity: 09-06-2022, 06:20 AM
Joined: 01-26-2017
Location: State College, PA
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MSI Optix Monitor--Functional but no image
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Sceptre X405BV -- Backlight on in standby?
I have a sceptre x405bv TV with bad LED strips. The screen displays dimly over the good LED's, and on disassembling it looks like over half of them are dead tested by multimeter diode test on test points. Plugging it in with the panel disconnected (this TV has a combined power and main board), the backlights immediately receive power when the set is plugged in. When the power button is pressed, it flashes brightly then dims, but additional LED's turn or flicker. When it's turned off again some back lights stay on.
Before I order replacement strips I wanted to ask if it is typical...Last edited by DoorOfTime; 04-04-2022, 10:19 AM. -
Re: Hisense 58r6e power board troubleshooting
Sure enough, there was a single bad LED on the strips that took out the entire TV. Unfortunately, one of the flat ribbon cables snagged while setting the screen back down and crimped badly enough to tear out an ~2 pixel wide line up the entire screen
Thanks for the assist guys... God I wish they made these ribbons reparable! -
Re: Hisense 58r6e power board troubleshooting
Thanks both for the replies--having the schematic is definitely helpful!
It looks like the readings with the main board unloaded aren't reflective of when the circuit is loaded, which was my mistake. Re-reading with the LED cable and main board connected, there's a steady +12V, STB is measuring at 2.9V, though VAMP is still measuring ~19V (I confirmed that VAMP is connected to VD821 and +12V to VD820).
Sure enough the voltage is hitting ~200V then dropping down within a second or two. Cheap...Leave a comment:
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Hisense 58r6e power board troubleshooting
Hi all, I browsed previous threads on Hisense TV's but had some questions I haven't been able to sort out myself. This TV has a red standby light that when powered on, flashes twice, returns to steady, and cycles a few times before returning to a steady solid red.
Poking around the power board (P/N rsag7.820.8349) I have the following voltages with everything disconnected:
[B]
Main board connector:[/B] 12V ~9.3, STB ~0, VAMP is transient; first measured ~18 and gradually dropping to sub-16V.
[B]Bridge Rectifier:[/B] (+) to (-): 167VDC
[B]Filter caps:[/B]... -
Re: Vizio E371vl--Decline to failure (diagnosis?)
Update:
Looks like I lost the 12V rail but not the 5V rail. Still haven't tracked down my faulty component, open to suggestions.Leave a comment:
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Re: Vizio E371vl--Decline to failure (diagnosis?)
So I finally got around to reflowing the mediatek chip this weekend. After being turned off since my last post, I reflowed the VGA side of the chip (which I had solder bridged before).
The TV worked for a good half hour on a VGA input. I tried to switch to an HDMI and the same old behavior cropped up--power cycling, standby ticking off, etc.
I reflowed the remaining sides of the chip and it kept behaving the same way, until... standby power cut out for good. There was a faint but audible crackle (was that there...Last edited by DoorOfTime; 03-19-2017, 02:12 PM.Leave a comment:
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Re: Vizio E371vl--Decline to failure (diagnosis?)
Finally got a chance to freeze the chips. The TV had been unplugged for ~2 days so it was functional when I turned it on.
Worth noting--the computer I used to connect to HDMI detected the TV as an output whether or not the TV was turned on.
While displaying HDMI on the screen I froze the EEPROM--no apparent change. Shortly after I started chilling the main chip the image cut out, the computer lost the HDMI output, and the TV powered down.
So, it looks like this is a main chip problem....Leave a comment:
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Re: Vizio E371vl--Decline to failure (diagnosis?)
This morning I plugged the TV in and turned it on--worked for ~10 minutes. I put a fan on it, insulated it a bit so it would heat up, pressed lightly on the chip--nothing changed its behavior. HDMI input flashing problem got worse over time, then the TV shut off and wouldn't turn back on. I unplugged and hard power reset it.
8 hours late I plugged it in and turned it on. It makes it as far as the menu, but when an input is plugged in it crashes. Took it outside for a while to chill--it's under freezing here. Brought...Leave a comment:
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Re: Vizio E371vl--Decline to failure (diagnosis?)
By "going funky", do you think this is a job that re-flowing the board would help or that it's a chip problem and the solution is getting a new one?
I was honestly hoping for an EEPROM problem for the learning opportunity! I've had some good discussions around using an Arduino to dump the EEPROM and compare to a previously compiled dump, maybe even modifying some existing Arduino projects to figure out how to re-write it. Can't even trust the E-series to fail predictably!Leave a comment:
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Re: Vizio E371vl--Decline to failure (diagnosis?)
Thanks for the input everyone. I decided to go ahead and re-solder all of the through-hole components on the main board thinking one of those may have cracked when somebody was jamming input cables into the board--no luck.
I checked every solder joint under magnification and re-soldered anything that looked fishy, but as you can imagine I didn't touch most of the small SM components.
At this point the TV will pretty consistently turn on and I can access the menu. I can switch inputs when nothing is plugged...Leave a comment:
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Re: Vizio E371vl--Decline to failure (diagnosis?)
Update: Plugged the TV in this evening (~10 hours later) and the unit powered up normally. Factory reset all settings, TV reset successfully.
Hooked it to a laptop VGA, screen operated completely normally for ~10 minutes. Tried to change inputs and the TV screen dropped back to standby. Turning it back on goes through the startup then drops back to standby again.
I was thinking this issue was related to EEPROM, but the periodic failures indicate it might be a failed/failing cap, a loose solder joint, or...Leave a comment:
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Re: Vizio E371vl--Decline to failure (diagnosis?)
Pictures attached...Last edited by DoorOfTime; 01-26-2017, 05:21 PM.Leave a comment:
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Vizio E371vl--Decline to failure (diagnosis?)
I've scoured this forum and several others for other E-series Vizio TV's and it seems I've got something unique going on here. I think the way this TV killed itself might grant insight into what went wrong, but I'm hoping some of the folks here might be able to confirm my diagnosis!
I picked up this TV a few days ago off the curb (a promising start, I know!) When I plugged it in everything looked fine--I had full access to the settings menu, IR panel is functional, and all of the buttons worked fine. "Why would somebdoy throw out a perfectly good flat-screen?"
...
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Re: New Members - please post your introductions here
Hi all,
I'm a DIY-ing hacker-wannabe. I'm a chemical engineer by background and a cheapskate by every measure. I got into electronics repair fixing surround sound systems and worn-out joysticks (curse you Soul Caliber II), and took more of a dive down the rabbit whole working in a wonderland of abandoned and disrepaired equipment in my school's basement-turned-scrap-storage.
Been lurking for a while trying to learn from my betters, awesome forum!Leave a comment:
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