kotel studios
Badcaps Veteran
Last Activity: 05-02-2026, 01:21 PM
Joined: 12-09-2024
Location: Lifes edge
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Note: The toshiba TA8202K can be used as a direct replacement for D6282 (aka. KIA6282K),and vice versa, they pretty much have the same specs. -
Concluded the VRM controller was dead, replaced it with a know good RT8120D and the VRM is working again. Sadly, the NB seems to be dead. I don't have any POST code execution nor any activity on the EEPROM pins. It also gets scorching hot in like 3-4 seconds from being turned on.Leave a comment:
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Desoldered the EC and both shorts went away. No current draw when I inject voltage on the +3VLP. And the current draw when I inject on PJ401 is ~60mA, so the cause for this havoc was a dead SIO. Kinda odd how it took out the 3.3v SY8208 too.
Sadly the costs of ordering a new SY8208, BQ24737, a few MOSFETs and EC are beyond what this laptop is worth, so off to the donor bin it goes.Leave a comment:
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Schematic says that it connects directly from BQ to the EC, so i guess not. Although the schematic is for the REV1.0 while mine is REV2.0, so I will still need to do a manual inspection.
Anything else I should check before desoldering the EC?Leave a comment:
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After measuring the charging circuit, I noticed the SCL pin of BQ24737 has a 1ohm short to GND. Removing the chip didn't resolve it.
So I then resorted to injecting 1V 1A on the VCC pin of SY8208B (it connects to the +3VLP rail). it resulted in only the Nuvoton NPCE288N heating up to ~30C. Upping the voltage to 2V makes it heat up to ~45C, at 3V 2A the EC goes up to ~78C.
Guess this confirms that the EC is at fault. But for a sanity check I will pull it off and see if the short is still there.Leave a comment:
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Lenovo G700 mainboard - unidentified short on the NB
Hi,
recently I went ahead and tried to tackle a repair I was putting off due to no experience and proper tools. It's a Lenovo G700 mainboard from a totaled chassis (previous owner banged it with a hammer, luckily the mainboard was mostly unscathed).
I had to remove the two CPU VRM caps since they were damaged. Otherwise there wasn't any more visible damage apart from the NB having a small chip on the edge closest to the biggest dot).
Powered it on and there was a barely noticeable squealing sound coming from the board (exact arena is unknown, but I think... -
Maxdata BIOS for Intel D915GEV
Hi,
Does anybody here have any maxdata OEM BIOS for intel D915GEV? Mine got corrupted and the one on TRW page is broken. Currently running on the gateway BIOS but it seems to be missing some settings present on the previous BIOS. -
HP NX5000 battery pack - wrong designed capacity, random 16V spikes on cell voltage
Hi,
Recently I wanted to finally tackle recelling my dead HP NX5000 battery pack (3S2P pack) since there aren't any replacements available. Before recelling it was detected as a valid battery and it's charge was always stuck at 50% (although it didn't hold any charge).
Two middle cells had rust on them, the 4 other weren't affected by it. BMS wasn't corroded in any way, was pretty much in prestine condition. Replaced them with some moderately used 3S2P (charged to 11.44V) pack from a lenovo battery.
At first, everything seemed to work. Battery was still detected,... -
Pulled out the core as a last resort.
All the caps on it were shorted, without it and the RAM ICs the short was still present.
So this is the end for this one. Off to scrap it goes.Leave a comment:
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BIOS for MSI Geforce GTX660 PCB model V287 VER 1.1
Hi
Uploading here my raw dump of the MSI Nvidia Geforce GTX660 card model N660-2GB/OC (PCB model V287 V1.1).
Before it cooked the core and RAM it worked fine.
Strings the TRW BIOS bot extracted
...Code:Class Type: [03] Display controller Subclass Type: [00] VGA compatible controller Programming Interface Type: [00] VGA controller Code Type: x86 (BIOS) NVidia VBIOS detected. Build date: 11/01/12 Subsys Vendor ID: 1462 Subsys ID: 2872 IBM VGA Compatible R11/01/12 3GK106 P2030 SKU 0 VGA BIOS
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There was an error. The TO-220 FP MOSFETs weren't from the E6 series but P6 series (this whole repair messed with my mind too much, I apologize for the confuson). The ones that I ordered in TO-220 were IPP60R190C6. Original ones were IPP60R190E6.
So it might've just been picky about the C6 and will work fine now. But I'll take this with a grain of salt now.
As a finale, I will order the TO-220 IPP60R190P6 MOSFETs from TME. And now I will take my time to actually test them without the heatsink first. If they don't burn out - blame the heatsink and be happy.
...Leave a comment:
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So I once again inspected the entire underside of the main PCB and the only short I could find was on GND pin of the FSB127H going to the output of the Vcc capacitor. It doesn't seem to be a big deal since these two traces get connected after another capacitor. Resolved this and went to testing with the IPA60R190E6.
Sure enough, the full pack MOSFETs generate all the rails correctly. I guess this would mean that the gates of IPP60R190 are still somehow getting shorted to GND.
But I don't think said short was the issue, if it was there when I was testing for the first time with...Leave a comment:
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So I've finally got to finishing this repair.
Deburred the holes (on both where the MOSFETs lay and where the screws are) and screwed whatever I had left of the functioning C6 FETs.
Soldered the heatsink back into the case, made sure none of the pins of the FETs were shorted to GND, flexed the heatsink back and forth but no shorts appeared. Made sure to triple check the solder for any bridges or cold joints.
Since no short were there I powered it on behind the bulb protection and.....
Same issue, no power rails are generated and the MOSFET closest to the primary...Leave a comment:
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Turns out, it was a dead amp. I switched them around since I only needed the external speaker amp and not the subwoofer, and everything seems to work flawlessly. Only downside is the D6282 is 4.6W max, but it's not like it was designed for high power speakers.Leave a comment:
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Huh, so let's say I remove the Vram coil, and the side where the MOSFETs connect to isn't shorted but the side where it goes to 2 caps and inside the board is, that means the core is dead, correct?
Sorry if I'm asking dumb questions but I just want to verify my hypothesis....Leave a comment:
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Out of curiosity I injected 750mV with 600mA max current on the Vcore inductors, and I only got a power draw of ~200-150mA. The die didn't get hot at all.
Also attempted removing RT8101, APA3516 and the main controller chip on the top side out of curiosity, but the short wasn't gone so either a single small component got short somewhere and is making core look dead, or the core is infact dead.Leave a comment:
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I think you meant vmem should not go beyond 0.5mA (0.500 A), right? Not 0.5mV?
Oh well, that's what I get for treating this card like trash... Such a bummer I can't save anything valuable from this one. I don't think I'll even be able to safely reuse the MOSFET drivers anywhere.Leave a comment:
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The pin on the underside of the mainboard isn't shorted, right?
Also you can send the mainboard photos.Leave a comment:
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MSI GTX 660 OC 2GB - short on Vmem
Hi
Recently my MSI GTX 660 OC (PCB marking "v287 V1.1", model G660-2GB5\OC) died during testing, tripping the PSU OCP. A few RAM chips and left heatsink pipe got up to ~120C.
Measuring the Vmem coil, it gave me <0 ohms to GND. There were a few caps on the GPU core showing the same resistance too (the ones pointing to the right RAM ICs).
Removed all of the RAM ICs and the short was gone (all RAM ICs were shorted on Vddq and Vdd).
Plugged it into my testing bench without the ICs and 12VHPWR and the short is back, albeit at 1.4 ohms.
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Yup, I use those washers.
Deburred them only on the side where the MOSFET tabs would go. Just to be on the safe side I'll deburr them once more. I was drilling those holes far away from the PSU in a vise, and after I was done I made sure to cut off any savings from the bench and the heatsink.
Yes, only one FET shorted when I flexed the heatsink. Now it doesn't do that (due to the extra silicon insulation). The tab was shorting to the heatsink which was shorting directly to the GND rail on the PSU mainboard.
Original MOSFETs didn't have anything attached to them, no ferride...Leave a comment:
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