Re: Vizio M420NV Powers on for a few seconds then resets
Well ended up ordering a new power board for this thing and its doing the same thing.
I know vizios are known for bad eeproms. Would what is happening here be in the same realm as a bad firmware chip.
Whatever it is, it seems like something is warming up, expanding, then faulting. Not sure where to go from here other than blindly order a new eeprom or mainboard. Any ideas?
EDIT: BTW, I was going to try and flash a newer firmware to see if that fixed it but I can't find any types of downloads...
kisk
Computer Tech
Last Activity: 08-29-2016, 06:23 AM
Joined: 01-17-2014
Location: Huntsville, AL
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Re: Funai "LF320EM4 A" Looking for this certain resistor..
I actually found a replacement power/mainboard for $15. Much cheaper than I was thinking. When the new board comes in I'm going to take some measurements and I will post them here in case anyone else in the future has a question about this board.
Thanks for the help!Leave a comment:
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Re: Funai "LF320EM4 A" Looking for this certain resistor..
Took both of the smaller diode's cathode out of circuit and they then both tested ok.
What is the correct way to measure the Q601 component? Does that need to come out of circuit as well?Leave a comment:
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Re: Funai "LF320EM4 A" Looking for this certain resistor..
Ok a little more testing..
A) These 4 seem fine. Getting 0.546 on all these in diode mode.
B) This diode reads shorted (0) both ways, but it looks like a different type of diode from the symbol on the back of the board.
C) Each of these pairs read 0.272, which I'm sure is because they are in parallel.
D) This little one reads 0.272 as well, but when I switch the leads the voltage slowly climbs to 1 then OLs.
E) Hope I'm testing this one...Leave a comment:
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Re: How to disable Computrac in dell e6420.
There is an internal OEM dell disk floating around that will allow you to reset/change computrace settings and service tag.Leave a comment:
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Re: Vizio e3d320vx stuck on V logo - Looking for schems/firmware
Just to update: I ended up buying a used mainboard for this set and it has worked flawlessly in the bedroom for almost a year.
Still haven't pulled the trigger on buying that programmer though
Leave a comment:
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Re: Funai "LF320EM4 A" Looking for this certain resistor..
Sorry to take so long getting back to this thread. Before I order the filter cap and fusible resistor are there any key points I should check out to possibly add to my parts list. Father in law has been patient but I think I've put this off too long.Leave a comment:
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Re: Vizio M420NV Powers on for a few seconds then resets
oops, pics:
And if I need to take additional pics let me know!...Leave a comment:
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Vizio M420NV Powers on for a few seconds then resets
I have a friend who's Vizio is having issues. I have the set here and have recapped the entire power board but still having the same issues.
From a cold start (>10m) the unit will stay powered on for about 2 minutes. After that time, it reboots. Each time it reboots the time till failure decreases. After about 5 reboots it only stays on for maybe 10 seconds then continues to reboot. If you leave the unit unplugged for about 10-15 minutes it will stay on for another 2 minutes or so before doing this all over.
He had actually called Vizio and they were going to send...Last edited by kisk; 01-13-2015, 09:37 PM. -
Re: Dell SE198WFPf - No standby
Just to update this. I replace the mainboard and the unit now works fine. $15 on eBay.Leave a comment:
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Funai "LF320EM4 A" Looking for this certain resistor..
My father-in-law bought a used camper and had a bad electric hookup coming in from his home (turned out to be a bad connector, or so he says). When you'd turn the lights on in the camper you could literally see everything pulsing at a pretty high frequency. I'd say 10 cycles per second. lol made me feel dizzy when I saw it.
Anyway, he fixed the issue, but not before it knocked out a microwave and two TVs, one being this one.
No standby light and of course after looking at the power board no wonder. The fuse (F602) is still good, but there is a plastic-block-housed... -
Re: Vizio 42" LCD Model SV420M, Black Screen no sound vizio Logo normal
Just wanted to say awesome thread and thanks for the bypass insight from both of you!Leave a comment:
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Re: Dell SE198WFPf - No standby
In your opinion is it even worth trying to diagnose the mainboard? I don't see anything physically wrong with it. From my limited experience there seems to be so much going on (controllers and such) that it would make it hard to pinpoint the exact problem -- at least on this mainboard.
If you have anything worth trying I'd love to give it a shot.Leave a comment:
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Dell SE198WFPf - No standby
No standby light and no power.
Wish I had a schematic for this board as I'm sure it would make things a lot easier.
I have replaced the caps on both the power and mainboard but no change.
Voltages on cable coming off of the power board read as follows (plugged in, no power):
1) 5.03V
2) 5.03V
3) -1mV (milli)
4) -1mV
5) 139.5mV
6) 2.355V
7) -9.6mV
8) 0.65V
There are no markings as far as what pins are what. Pressing power button does not change any values.
CN104 on the mainboard... -
Re: Seiki SC402TT Show logo, then cuts off
Just tried all 3 HDMI ports and the VGA -- same response. BTW, I did not replace the big honkin single cap on the powerboard. I've read these don't go out often. Should I go ahead and replace the smaller thin caps on the mainboard or is there anything else I should try first.Leave a comment:
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Re: Seiki SC402TT Show logo, then cuts off
Sorry for the long delay. I've been busy and finally getting back to this set. Got this set from someone and didn't get any substantial history on it so I'm not sure what they had hooked up input wise. They had had it put away for awhile and couldn't remember much.
I changed all the caps on the power board, and 4 of the bigger caps on the mainboard. Didn't get to change out three 330uf 35v on the mainboard as I didn't have any on hand. Have some on order. In addition, didn't have any 390uF 35v for the inverter -- those are...Leave a comment:
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Seiki SC402TT Show logo, then cuts off
TV cuts on (red to blue SB light), shows logo for about 10sec, then cuts off. SB light back to red, no flashes. 10 seconds is long enough to test all voltages on the lines and everything looks good. BL powers on without problems.
No cap bulges or leakage. I just got a new MESR-100 v2 capacitor tester and I think I'm using this thing correctly O.o
It seems like a mainboard issue but I'm not totally sure. I had a Vizio that did almost the exact same thing -- came to the conclusion it was a firmware issue but unfortunately I didn't have the equipment to program a Hyrix eeprom.... -
Re: LG 42LS3400 - No power
Well, have a new power board on the way, but if anyone has any ideas I'd love to try them in the meantime. Thanks!Leave a comment:
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Re: LG 42LS3400 - No power
Checked the 2 mosfets on the bottom of the power board as well. Here are the readings, in kOhms:
Q101:
GD = OL
GS = .051
DS = OL
Q102:
GD = OL
GS = OL
DS = OL
Can barely read the tops of these mosfets, but this is the best identification I can make out:
10MN6
ON
6K16b214
Hope this leads us closer
Last edited by kisk; 03-09-2014, 11:52 AM.Leave a comment:
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LG 42LS3400 - No power
Hoping you guys could help me diagnose this LCD TV. Standby light is solid red when unit is plugged it. On power-on, the standby light flashes 3 times and then stays off. No visible damage, caps look ok, and fuses check out ok (shorted).
Attached is the service manual and some pics of the boards.
Here are the voltages I'm getting off of the pins when the unit is "on". The low voltages seem to be in spec, but nothing on 12 or 24v.
P201:
Left row, top to bottom (see pic for V reference)
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87.3 mV
87.3 mV
87.3 mV...Last edited by kisk; 03-09-2014, 11:26 AM.
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