Inspiron 1501 Repair Reference
Dell Inspiron 1501 Repair notes
The Dell Inspiron 1501 has a very compact mainboard. Care must be taken whilst removing the TSOP BIOS Chip or the Power socket, as there are quite a few small resistors and other components nearby which can be dislodged really easilly.
The labels on the mainboard contained the following text. label 1 BGT6C3381. Label 2 CN-0UW953-48643-6C4-6947, REV A01.
The BIOS Chip in this instance was the SST 39VF080 70-4C-EIE 40 pin TSOP, although I have seen this mainboard fitted with the MX29LV008CB also. BIOS Chip is located just above the right hand inner corner.
Two images top and bottom views of motherboard. Click on images below to view a larger image
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Inspiron 1501 Password Removal
We are able to remove bios passwords on this machine. This laptop uses an ST M24C08WP EEPROM as a security chip, it is located adjacent to one of the memory slots.
To remove the bios password, the security chip needs to be blanked, and also the bios needs to be erased and re flashed in one operation, before powering up the machine. Best also to remove cmos battery whilst refitting the newly programmed eeprom and security chip.
Our attempt at removing the BIOS password worked fine 2nd time around, and I was able to enter cmos setup after the repair.
Clearing the Security chip alone (first attempt) did not have any affect on bios password.
Inspiron 1501 Power Socket Repair
We are also able to replace the power socket on this machine. Other components need to be checked as well as the socket.
We use a hot air station to remove the old socket. The through board holes are best cleared using the hot air and some suitable solder soaker cut to a point.
The new socket is fitted using an ESD safe iron, then re flowed completely with Hot air.
Whilst removing the socket do not blow on the board or use compressed air in an attempt to clear the through board holes or you will loose most of the surrounding SMD components.
It is also important not no move the board or knock/shock it whist working with the hot air or you could dislodge any heated SMD parts
Capillary action would normally keep components in place even though solder is fluid when heated, but shock or tap the board and its a whole different story.
Observations
First attempt at power socket repair proved fruitless. I decided to take a second look and examined the board using a 30 x eye glass.
Alongside the power socket there is a rather large SMD resistor that just didn't look right.
After examining the part with an eye glass a crack could clearly be seen between the solder and the resistor at one end.
Using an OHM meter proved conclusive the resistor had a value if checked across its body, however when checked between the solder points it showed open circuit. Once the resistor had been re soldered the laptop booted fine and is now charging once again.
This resistor needs to be re soldered as it can develop a dry joint and stop the machine powering up even after replacing the power socket.
Before the Resistor dry joint repair the battery was showing as unknown, however, after re soldering the resistor the battery is now being recognized.
Dell Power Supplies
Dell use a third wire in their power supplies which serves no real purpose other than making sure you use an original Dell power supply. You cannot use most third party power supplies, it has to be a Dell replacement or a convincing third party replacement.
The third wire setup which is rather troublesome, is used for monitoring the authenticity of the power supply being used and nothing else.