I've got a Lenovo Thinkpad L580 with a 01LW293 motherboard that doesn't power on, or respond to a charger.
It's got 2 bios chips, U4502 located near the ac input (25L8006E)
and U0901 located near the dimm slot (25L12873F).
Can anyone tell me which bios is doing what?
I'm guessing U4502 is corrupt causing everything else to fail.
I've found the main bios image at 16M, but nothing for the 1mb one.
Thanks.
dabone
Member
Last Activity: 01-09-2024, 01:02 PM
Joined: 08-18-2010
Location:
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Lenovo L580 with 01LW293 Motherboard, No power
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Re: Vizio E420-A0 with bad EEPROM
Does anyone have a copy of the eprom image? I've got one that has good standby voltage, but power button does nothing.
My board is a 3642-1742-0150. Same as the board at the start of the thread.
Thanks. -
43mv314x/f7 blown Power Supply
I was handed a 43mv314x/f7 to look at and on first inspection, no power, no led. So I opened the unit, and have been looking at the PSU.
It's a BA4DV2F0102 2, and doing a quick check of the though hole components, the main fuse is blown, q601 (K7A6QX) is a dead short, and one diode on the low voltage side D655 (SB3A0) seems to be dead also .
My searching has come up empty on this model. Does anyone have suggestions for this one, since I'm seeing multiple blown parts, I'm guessing it has taken out some of the surface mount stuff on the flip side.
Thanks.... -
Re: LG 42LD550 issues
I used my hotair rework station and just heated the chip along with it's heatsink nearest the lcd cables, I used 285c moving constantly around the heat sink, (I have a small nozzle installed currently)
It's now working fine and if it fails again, I'll try to remember to post back here as to how long the repair lasted.Leave a comment:
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Re: dell inspiron 3521 bios need.
I've got a 3521 here, and the eprom at uh2 has failed, and I can't read the eprom type.
(The chip has physical damage..)
Can anyone tell me the replacement for this chip?
Thanks.Leave a comment:
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Re: VW42L Help please, powers on with backlights, no menus
[URL="http://assets.shopjimmy.com/media/catalog/product/cache/1/image/f8f28dc4a19c21aeb55ee5774693fb5d/s/h/shopjimmy-3642-0252-0150-top_1.jpg"]http://assets.shopjimmy.com/media/catalog/product/cache/1/image/f8f28dc4a19c21aeb55ee5774693fb5d/s/h/shopjimmy-3642-0252-0150-top_1.jpg[/URL]
You can see it in this picture, it's located below the j7 connector.Re: VW42L Help please, powers on with backlights, no menus
[URL="http://assets.shopjimmy.com/media/catalog/product/cache/1/image/f8f28dc4a19c21aeb55ee5774693fb5d/s/h/shopjimmy-3642-0252-0150-top_1.jpg"]http://assets.shopjimmy.com/media/catalog/product/cache/1/image/f8f28dc4a19c21aeb55ee5774693fb5d/s/h/shopjimmy-3642-0252-0150-top_1.jpg[/URL]Leave a comment:
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VW42L Help please, powers on with backlights, no menus
I'm working on a craigslist find, a VW42L with a 3642-0252-0150 Mainboard.
I bought it with the usual story told to me that it just quit working.
After I opened the tv, I could see that they had tried repairing the mainboard by replacing the 1117 regulators at u2, u7, u8, u9 and a 1718 at u33.
I checked the PSU model 0500-0507-0450 and found that it was bad, (no powering up when voltage applied to the pson pin)
So instead of fixing that PSU I ordered a 0500-0507-210 from ebay, and installed it.
Now the TV comes on, turns... -
Re: Westinghouse VR-4085DF / MLT668TL-V Power supply troubleshooting
I ended up buying a substitute board off ebay straight from china.
It plugged straight in, but the mounting is the strangest thing, It came with 4 stand offs that have magnets on the bottom. So, I wouldn't want to ever ship this thing.
But it works just fine. And the board only cost $16.00 + shipping.
You know that the original boards are crap when someone took the time to make a drop in sub.
Later,
daboneLeave a comment:
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Re: Westinghouse VR-4085DF / MLT668TL-V Power supply troubleshooting
Well crap, It worked for about 2 hours, and now I've lost backlight again.
Now the fuses are stable, but when the inverter board is connected I lose my +24v.
Grrrr.
Later,
daboneLeave a comment:
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Re: Westinghouse VR-4085DF / MLT668TL-V Power supply troubleshooting
Well I got the rebuild kit, I figured that the used board would need it eventually also. As for skills, I've got em, and the hot air rework station.
.
So for my TV, it took 2 caps in the PSU, and the rebuild kit on the inverter board. It's up and running, and I'll leave it on all day tomorrow when I'm back in my shop to test some more.
Later,
daboneLeave a comment:
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Re: Westinghouse VR-4085DF / MLT668TL-V Power supply troubleshooting
It's that inverter board.
And I thought I had checked the fuses, but checking again today, f102 is open.
No stock on boards, do you think I should just get this and install it?
I've currently got $25 in the tv, and my labor is free.
[url]http://www.shopjimmy.com/samsung-lj97-02098f-ssi-400-14a01-backlight-inverter-component-repair-kit.htm[/url]
Or there is a used one available for $23.00Re: Westinghouse VR-4085DF / MLT668T...roubleshootingLast edited by dabone; 06-07-2016, 07:06 AM.Leave a comment:
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Re: Westinghouse VR-4085DF / MLT668TL-V Power supply troubleshooting
I've got one of these,power button responds, turns on the +24 and +12 voltages with the inverter attached. 4 Volts appears on the STB, but never any backlights.
I had a couple of dead 1000uf caps on the psu I replaced. (c10 and c16)
I also replaced the 1000uf caps at c14 and c15 also, since I had extras.
So to recap, I have voltages, but no happiness.
Comments? Suggestions?
Thanks.Leave a comment:
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Vizio E420VL Logo then black problem and solution.
I recently picked up a E420VL Vizio, with the following problem.
It would power on, show the logo and then go to a black screen.
After awhile, it would then show HDMI2 on the display, and then power off.
I ordered an eeprom, and replaced it with no change in symptoms.
I then found another thread and a video with it being the IR board.
I unplugged the ir board and the tv is now working correctly.
I've ordered a replacement ir board, and will post the results after I receive it.
I'm posting this for... -
Re: Polaroid FLM-3232, blue led, no back light, no pic, no sound.
Ok, I replaced the 10uf @50s and the 1uf@50 and the 47uf@50 in the upper left quadrant. I also removed the upper transformer between the sections, and I still get the ramp up/shutdown symptoms.
Even removing TR1, which is a 2.2uf 450W cap, the power is still fluctuating on the main cap.
I'm pulling all diodes and checking them currently.
Later,
daboneLast edited by dabone; 09-02-2015, 10:32 AM.Leave a comment:
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Polaroid FLM-3232, blue led, no back light, no pic, no sound.
I'm working on a Polaroid FLM-3232 with a 846-240-H3CZZS PSU.
The tv will power on to a blue led, no pic, no sound.
When I power up the psu I hear something shorting, then restarting over and over in the hv section.
Powered off the large cap reads 156.1 DC, but powering on the psu, even without any load produces anywhere from 191 to 220 DC,
constantly jumping, hearing the tick from the hv side of the psu following the voltage jumps.
The tick appears to the coming from the transformer in the upper left corner of the board.
I've checked... -
Re: Megmeet MLT668TL-V rev 1.1 Help please.
It's very close to the 1.5 Circuit, I can't find a 1.1 schematic.
[URL="http://www.svfdtn.com/mtx/megmeet_mlt668_rev.1.5_power_supply_sch.pdf"]http://www.svfdtn.com/mtx/megmeet_mlt668_rev.1.5_power_supply_sch.pdf[/URL]
Thanks.Re: Megmeet MLT668TL-V rev 1.1 Help please.
It's very close to the 1.5 Circuit, I can't find a 1.1 schematic.
[URL="http://www.svfdtn.com/mtx/megmeet_mlt668_rev.1.5_power_supply_sch.pdf"]http://www.svfdtn.com/mtx/megmeet_mlt668_rev.1.5_power_supply_sch.pdf[/URL]Leave a comment:
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Megmeet MLT668TL-V rev 1.1 Help please.
I did a whoops while working on some tvs this weekend.
I had a working MLT668TL-V rev 1.1 supply testing a couple of tvs, and while testing I sat the board down on the back of a panel before the main cap discharged, resulting in a large pop. (The board wasn't plugged into anything at this point.)
Now the standby power is cycling every second or so.
Any clues on where to start?
Thanks.
Later,
dabone -
Re: 47LS4500-UD, Help please.
Ok, the replacement board was missing components.... &*%*&%*&% ebay...
Later,
daboneLeave a comment:
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47LS4500-UD, Help please.
I picked up a LG 47LS4500-UD the other day with storm damage.
The power supply was shorted for the standby voltages with the mainboard connected.
Removing the mainboard and powering up the power supply gave me all my voltages. (3.3, 5, 12, and 24).
So I ordered another motherboard, and received it today, and I put it in, the standby voltage is steady, but no light on the front, and no way to turn on the tv. Now the strange thing about this is that the tv uses a touch control for the front panel, but the connector going to the io board has NO voltage that I...Last edited by dabone; 06-04-2014, 01:44 PM. -
Look for Datasheet
I'm working on a VR-4085DF Tv, and I'm looking for the datasheet for the inverter chip.
It's a SEM2107, on a Samsung branded inverter board labeled
SSI_400_14A01.
It's got the 2 seconds to black, and I'm thinking I might have bad lamps.
Later,
dabone
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