Well, cleaning the BIOS was worth a try. It had all the classic symptoms. Now I have a T48 programmer and a thirst for knowledge. There are no failures -- only learning opportunities!
Dana...
Thank you to the guys at HEGE supporting Badcaps [ HEGE ] [ HEGE DEX Chart ]
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@hoaca388
Thank you very much for your help. I will use your BIN to program my BIOS chip some time this week when I have time. I will let you know if I get a good POST using it.
Dana...
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I recently bought a Dell Inspiron 5570 laptop, service tag H0GFXR2, from an eBay seller. The eBay item description stated, "This laptop does not power on - no lights, no beeps."
The motherboard is a LA-F114P, Rev 1.0 A00, 2017-09-04.
I have removed the motherboard from the chassis, and tested it using a charger only, with no batteries. The motherboard does power on, but it does not POST. There is no screen output, and I have confirmed that the screen and backlight work fine using the "press D, then Power" procedure to display solid colors on the screen....
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As a hobby, for the past three years I have been buying, repairing, and refurbishing Dell Inspiron laptops -- mostly 5570, 5770, and 7573 models. I have a multimeter, bench power supply, and soldering tools. I recently purchased a T48 programmer, because I have a laptop with a possible corrupted BIOS. I would really love to learn how to clean and repair BIOS bin file dumps. I have been working with Hex editors for many years, so I think I can learn BIOS repair skills. I love to find shorted caps, and I hate to find shorted PCH and EC chips!
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Re: CAL60 LA-F114P Rev: 1.0 (A00) Schematic needed
The rar file posted contains "Dell Inspiron 5570.cad", which I cannot open using Allegro Free Physical Viewer 22.1. The program says that the cad file is corrupted.
The Allegro viewer can open LA-F115PR10-0728D_Gerber.brd just fine, but not the cad file.
Is there another viewer I should be using?
Thank you...
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Re: Dell Inspiron 5570 CAL60 LA-F114P
@Mon2
I have taken resistance and voltage readings from a fully functional CAL60 LA-F114P motherboard (Inspiron 5570/5770). Could you please review my findings below, and in the three attachments I have uploaded? I would appreciate your feedback.
On the edge of the CAL60 LA-F114P motherboard (under DC_IN)
between PQ1 and PD2 (absent) there are five resistors:
PR5, 2.2K-ohm (nearest the edge of the board)
PR1, 33-ohm
PR3, 100K-ohm
PR6, 15K-ohm
PR4, 10K-ohm (between PQ2 and the missing...
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Re: Dell Inspiron 15 5570 Plugged in not charging
Well now. I was able to remove a PD1 TVS diode from an old 7th gen motherboard, and transplant it to an 8th gen motherboard with a blown diode. That makes me very happy.
Removing these microscopic chips is easy, but soldering them onto a motherboard is extremely difficult for newbs like myself. But it works perfectly, and my test readings show that the transplanted TVS diode is working.
With meter in diode mode, and negative probe on ground, the diode does not conduct. With the positive probe on ground,...
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Re: Dell Inspiron 15 5570 Plugged in not charging
Well, I was close!
My donor board had a good PQ1 and a blown PD1. I removed the blown PD1, and the board recognized the Dell charger again. However, when I removed the blown PD1, it ripped out the pad near PL3. That is OK -- it's a donor board.
So I harvested PQ1, PD5, and PD6 from the donor board to use on my "target" board.
My "target" board had a blown PQ1, so I suspected PD1 was also questionable, since it did not protect PQ1 as it should have. I removed PQ1 and PD1...Last edited by dana.repouille; 03-07-2023, 07:57 PM.
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Re: Dell Inspiron 15 5570 Plugged in not charging
I agree with that, especially since PD1 is connected to the center pin of the charger, and is routinely abused each time the charger is connected. My theory was that I could harvest PD5 and PD6 from the battery's data and clock lines of donor boards, and use them to replace PD1.
I just now removed a blown PD1 from a motherboard, and it worked (charged the battery) perfectly! However, the SOT523-3 package is so darn tiny that I can't imagine how I am going to install a replacement onto those tiny pads....
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Re: Dell Inspiron 15 5570 Plugged in not charging
I appreciate the link, and may order some from Mouser.
I found two listings for SP0502BAHTG on eBay. Oddly enough, both listings state this is a "SP0502BAHTG SOT-23 Littelfuse Diodes - TVS" rather than a SOT523-3. I often worry that eBay listings are inaccurate, especially when accuracy matters the most....
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Re: Dell Inspiron 15 5570 Plugged in not charging
Agreed. Since we don't know the specifications of the original part, how do we know which model of TVS diode to order?
It looks like they cost about 50 cents each for a lot of 100, so about $50 for 100? It seems like someone on eBay could make money buying 3,000 of these, and cutting them into smaller strips. If they list them on eBay as Dell Inspiron TVS diodes, I would buy them.
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Re: Dell Inspiron 15 5570 Plugged in not charging
There appear to be four TVNST52302AB0_SOT523-3 packages on the motherboard. In addition to PD1, PD5, and PD6, I think EU4012 is the same package type. It appears to be connected to Pin 2 of JFP1, the fingerprint reader connection. However, when I look for it on LA-F115P TOP.pdf, it appears in the middle of the board, nowhere near the fingerprint reader connector. Now I need to examine the motherboard under a scope to find EU4012.
I'm just looking for all the spare TVS diodes that I can harvest from donor boards to replace...
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Re: Dell Inspiron 15 5570 Plugged in not charging
Thank you. Even though the TVS diode on the daughterboard is in the same SOT23-3 package, it has a different part number than PD1, PD5, and PD6 on the motherboard. I assume it has different thresholds, so it would not be safe to use it to replace the other three TVS diodes. That may be because the USB port uses 5V, while the data lines on the motherboard use 3.3V. Just guessing here.
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Re: Dell Inspiron 15 5570 Plugged in not charging
The Dell Inspiron I/O daughterboard (for USB 2.0, SD card reader, and CR2032 battery) is LS-F111P. It appears to have a similar TVS diode labeled DI1 next to the USB port. However, it seems to be a different part number than the three TVS diodes on the motherboard.
Is a schematic for the LS-F111P available for download?...
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Re: Dell Inspiron 15 5570 Plugged in not charging
I have donor motherboards for the Inspiron 5570. The schematic indicates that PD1, PD5, and PD6 are all TVNST52302AB0_SOT523-3. PD1 is connected to the charger sense pin, while PD5 and PD6 are connected to the battery data and clock pins. That makes it easier to find cheap replacement parts. Thanks for the schematic!
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