I have the same fan (Honeywell HO-5500RE) and I'm also missing the 5 VDC rail. I injected 5 V via an USB charger and the fan started working again. I know a little bit about electronics and also designed and build some PCBs but this 5 V power supply looks funky to me (looks like they saved every penny possible). Like mentioned before the 5 V are connected somehow to mains voltage on one side? I also check D1, 2 and 3 which are fine and R1, 2 and 3. I changed R3 for two 1 Mohm resistors in series to replace the old 2 Mohm resistor which only showed me 1 Mohm on the multimeter. Other then that I don't know what to check. Maybe someone can help or explain to me how the 5 v are created? Nothing looks burned or blown.
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this has schematics
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This is only the pwm power switch, which is working fine. Or does it create the 5v? I'm not sure.
E: Sorry I misunderstood the purpose of the IC. How can I check if the IC is working?Comment
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i think it uses the inductor to generate 5v
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I changed the OB2223AP IC and now the fan is working again.
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Hi
I am trying to repair an ancient Dell 2209WA Monitor which suddenly shut off with a pop sound. On investigation found that one of the fusible resistors had blown. Further investigation identified multiple components as faulty because of which the fusible resistor blew. Please refer the attached circuit diagram showing the components that were found to be damaged.
1. FR950 - blown fusible resistor - 0.2 Ohm 1W
2. Q950 - shorted Q950 MOSFET - 650V 10A N Channel Mosfet
3. R835 - Blown Resistor - 20KOhm SMD resistor
4. D930 - Shorted Schottkey Diode... -
Hi to all forum members,
Got this faulty 350 watt atx psu dirt cheap from a local online seller as i am keen to use it as a learning tool to repair faulty power supply.
The faulty part is quite obvious from the burn area near the 16pin KA7500 BD pwm. The fuse is still intact with good continuity.
Upon power on ac, there is 5vdc standby power on cathode of diode D14 and about 10vdc on cathode of diode D13.(This should be the aux power to generate the 12v and 5v rail.)
Initially i replace the two burned resistors near my marked red arrow to 200 ohm resistor... -
I got Acer Aspire A715-42G, no 19v going through the DC-IN mosfet. I also checked the components/power rails downstream and no short detected (gpu and cpu rails are at 2-10 ohms)
I have checked that there's no gate voltage on the DC-IN mosfet, so I checked if PUB1 has power.
Turns out there's no 19v going into PUB1 VCC caused by a burnt 10 ohm resistor (PRB12 - 19v stops here).
Replaced the part but it burned when I plugged in the charger - telling me there's something pulling high current.
I checked the resistance of PCB16 and it was fine.
I measured the resistance...09-20-2024, 02:18 AM -
This specification for the HP Z230 Tower can be useful for upgrading or repairing a desktop PC that is not working. As a community we are working through our specifications to add valuable data like the Z230 Tower boardview and Z230 Tower schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note that we offer no warranties that any specification, datasheet, or download for HP Z230 Tower is...09-12-2024, 03:44 PM
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This specification for the HP Z240 Tower Workstation can be useful for upgrading or repairing a desktop PC that is not working. As a community we are working through our specifications to add valuable data like the Z240 Tower Workstation boardview and Z240 Tower Workstation schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note that we offer no warranties that any specification, datasheet,...09-12-2024, 03:44 PM
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