HP Split 13 x2 – Disassembling procedure – How to remove the batteries – How to remove the base cover – How to replace the RTC battery – How to update the BIOS

HP Split 13 x2 disassembling procedure 

How to remove Base enclosure

Before disassembling the keyboard dock, follow these steps:
1. Shut down the keyboard dock. If you are unsure whether the computer is off or in Hibernation, turn the computer on, and then shut it down through the operating system.
2. Disconnect all external devices connected to the computer.
3. Disconnect the power from the computer by first unplugging the power cord from the AC outlet and then unplugging the AC adapter from the computer.
4. Disconnect the tablet from the keyboard dock
Remove the base enclosure:
1. Remove the two upper rubber feet (2), and then the two Phillips PM2.5×6.0 screws (3) underneath.
2. Separate and release the base enclosure (4) from the dock.

How to remove Hard drive

Before removing the hard drive, follow these steps:
1. Shut down the computer. If you are unsure whether the computer is off or in Hibernation, turn the computer on, and then shut it down through the operating system.
2. Disconnect all external devices connected to the computer.
3. Disconnect the power from the computer by first unplugging the power cord from the AC outlet and then unplugging the AC adapter from the computer.
4. Disconnect the tablet from the keyboard dock
5. Remove the base enclosure
6. Disconnect the battery cable.

Remove the hard drive:

1. Remove the three Phillips PM2.0×5.0 screws (1) that secure the hard drive to the dock.
2. Disconnect the hard drive cable (2) from the hard drive.

3. Remove the hard drive from the dock (3).

How to remove Hinge assembly

Before removing the hinge, follow these steps:
1. Shut down the computer. If you are unsure whether the computer is off or in Hibernation, turn the computer on, and then shut it down through the operating system.
2. Disconnect all external devices connected to the computer.
3. Disconnect the power from the computer by first unplugging the power cord from the AC outlet and then unplugging the AC adapter from the computer.
4. Disconnect the tablet from the keyboard dock
5. Remove the base enclosure
6. Disconnect the battery cable.

 Remove the hinge assembly:

1. Remove the four Phillips PM2.5×5.0 screws (1) that secure the hinge to the dock.
2. Disconnect the cables from each side of the dock (2).

3. Lift the hinge assembly (3) from the dock.

How to remove Battery

Before removing the battery, follow these steps:
1. Shut down the computer. If you are unsure whether the computer is off or in Hibernation, turn the computer on, and then shut it down through the operating system.
2. Disconnect all external devices connected to the computer.
3. Disconnect the power from the computer by first unplugging the power cord from the AC outlet and then unplugging the AC adapter from the computer.
4. Disconnect the tablet from the keyboard dock
5. Remove the base enclosure

6. Disconnect the battery cable.

Remove the battery:

1. Remove the six Phillips PM2.0×4.0 screws (1) that secure the battery to the dock.
2. Remove the battery (2) from the dock.

How to remove Display rear cover

Before removing the display rear cover, follow these steps:
1. Shut down the computer. If you are unsure whether the computer is off or in Hibernation, turn the computer on, and then shut it down through the operating system.
2. Disconnect all external devices connected to the computer.
3. Disconnect the power from the computer by first unplugging the power cord from the AC outlet and then unplugging the AC adapter from the computer.
4. Disconnect the tablet from the keyboard dock
Remove the display rear cover:
1. Remove the two rubber screw covers (1) and two Phillips PM2.0×3.0 screws (2) that secure the cover to the tablet.
2. Using the slot in the cover, lift the cover off the tablet (3)

How to remove Battery cable

You do not have to remove the internal battery before removing several internal components. However, if you leave the battery installed while removing components, be sure to disconnect the battery cable from the system board to remove power from internal components.
Before disconnecting the battery cable, follow these steps:
1. Shut down the computer. If you are unsure whether the computer is off or in Hibernation, turn the computer on, and then shut it down through the operating system.
2. Disconnect all external devices connected to the computer.
3. Disconnect the power from the computer by first unplugging the power cord from the AC outlet and then unplugging the AC adapter from the computer.
4. Disconnect the tablet from the keyboard dock
5. Remove the display rear cover
Disconnect the battery cable:
Lift the tape on top of the connector (1), and then disconnect the battery cable from the system board
connector (2).

How to remove RTC battery

Before removing the RTC battery, follow these steps:
1. Shut down the computer. If you are unsure whether the computer is off or in Hibernation, turn the computer on, and then shut it down through the operating system.
2. Disconnect all external devices connected to the computer.
3. Disconnect the power from the computer by first unplugging the power cord from the AC outlet, and then unplugging the AC adapter from the computer.
4. Disconnect the tablet from the keyboard dock
5. Remove the display rear cover
6. Disconnect the battery cable
Remove the RTC battery:
1. Use a screwdriver to loosen the battery from the socket (1).
2. Lift the battery from the socket (2).

How to remove Battery

The tablet includes an internal battery.
Before removing the battery, follow these steps:
1. Shut down the computer. If you are unsure whether the computer is off or in Hibernation, turn the computer on, and then shut it down through the operating system.
2. Disconnect all external devices connected to the computer.
3. Disconnect the power from the computer by first unplugging the power cord from the AC outlet and then unplugging the AC adapter from the computer.
4. Disconnect the tablet from the keyboard dock
5. Remove the display rear cover 
6. Disconnect the battery cable 
1. Disconnect the HT cable (1).
2. Remove the Phillips broad-head PM2.0×3.0 screw (2) and the four Phillips PM2.0×5.0 screws (3) that secure the battery to the tablet.
3. Remove the battery (4) from the tablet.

BIOS update

1. From the Start screen, type support, and then select the HP Support Assistant app.
2. Click Updates and tune-ups, and then click Check for HP updates now.
3. Follow the on-screen instructions.
4. At the download area, follow these steps:
a. Identify the most recent BIOS update and compare it to the BIOS version currently installed on your computer. If the update is more recent than your BIOS, make a note of the date, name, or other identifier. You may need this information to locate the update later, after it has been downloaded to your hard drive.
b. Follow the on-screen instructions to download your selection to the hard drive.
If the update is more recent than your BIOS, make a note of the path to the location on your hard drive where the BIOS update is downloaded. You will need to access this path when you are ready to install the update.

BIOS installation procedures vary. Follow any instructions that are displayed on the screen after the download is complete. If no instructions are displayed, follow these steps:
1. From the Start screen, type e, and then select File Explorer.
2. Click your hard drive designation. The hard drive designation is typically Local Disk (C:).
3. Using the hard drive path you recorded earlier, open the folder on your hard drive that contains the update.
4. Double-click the file that has an .exe extension (for example, filename.exe).
The BIOS installation begins.
5. Complete the installation by following the on-screen instructions.

How to replace and reset lamp – BenQ MX613ST, BenQW1080, BenQW1070 projectors

BenQ MX613ST

Replacing the lamp

• To reduce the risk of electrical shock, always turn the projector off and disconnect the power cord before changing the lamp.

• To reduce the risk of severe burns, allow the projector to cool for at least 45 minutes before replacing the lamp.

• To reduce the risk of injuries to fingers and damage to internal components, use caution when removing lamp glass that has shattered into sharp pieces.

• To reduce the risk of injuries to fingers and/or compromising image quality by touching the lens, do not touch the empty lamp compartment when the lamp is removed.

• This lamp contains mercury. Consult your local hazardous waste regulations to dispose of this lamp in a proper manner.

• To assure optimal performance from the projector,it is recommended that you purchase a qualified projector lamp for lamp replacement.

• If lamp replacement is performed while the projector is suspended upside-down from the ceiling, make sure that no one is underneath the lamp socket to avoid any possible injury or damage to the human eyes caused by fractured lamp.

1. Turn the power off and disconnect the projector from the power outlet. If the lamp is hot, avoid burns by waiting for approximately 45 minutes until the lamp has cooled.

2. Loosen the screw(s) that secures the lamp cover on the side of the projector until the lamp cover loosens

3. Remove the lamp cover from the projector.

• Do not turn the power on with the lamp cover removed.

• Do not insert your fingers between the lamp and the projector. The sharp edges inside the projector may cause injuries.

4. Disconnect the lamp connector from the projector as illustrated.

5. Loosen the screw that secures the lamp.

6. Lift the handle so that it stands up

7. Use the handle to slowly pull the lamp out of the projector.

• Pulling it too quickly may cause the lamp to break and scatter broken glass in the projector.

• Do not place the lamp in locations where water might splash on it, children can reach it, or near flammable materials.

• Do not insert your hands into the projector after the lamp is removed. If you touch the optical components inside, it could cause color unevenness and distortion of the projected images.

8.  Lower the new lamp

9. Tighten the screw that secures the lamp.

10. Ensure the handle is fully laid flat and locked in place.

11. Reconnect the lamp connector.

• Loose screw may cause a bad connection, which could result in malfunction.

• Do not over tighten the screw

12. Replace the lamp cover on the projector.

13. Tighten the screw(s) that secures the lamp cover.

• Loose screw may cause a bad connection, which could result in malfunction.

• Do not over tighten the screw.

14. Connect the power and restart the projector. Do not turn the power on with the lamp cover removed.

Resetting the lamp timer

15. After the start up logo, open the On-Screen Display (OSD) menu. Go to the SYSTEM SETUP: Advanced> Lamp Settings menu. Press MODE/ENTER. The Lamp Settings page displays. Highlight Reset Lamp Timer. A warning message is displayed asking if you want to reset the lamp timer. Highlight Reset and press MODE/ENTER. The lamp time will be reset to “0”. Do not reset if the lamp is not new or replaced as this could cause damage.

BenQ W1080, W1070

Replacing the lamp

• To reduce the risk of electrical shock, always turn the projector off and disconnect the power cable before changing the lamp.

• To reduce the risk of severe burns, allow the projector to cool for at least 45 minutes before replacing the lamp.

• To reduce the risk of injuries to fingers and damage to internal components, use caution when removing lamp glass that has shattered into sharp pieces.

• To reduce the risk of injuries to fingers and/or compromising image quality by touching the lens, do not touch the empty lamp compartment when the lamp is removed.

• This lamp contains mercury. Consult your local hazardous waste regulations to dispose of this lamp in a proper manner. Status Message Install a new lamp for optimal performance. If the projector is normally run with Economics elected , you may continue to operate the projector until the next hour lamp warning appears. Press MODE/ENTER to dismiss the message. It is strongly recommended that you replace the lamp at this stage. The lamp is a consumable item. The lamp brightness diminishes with use. This is normal lamp behavior. You can replace the lamp whenever you notice that the brightness level has significantly diminished. Press MODE/ENTER to dismiss the message. The lamp MUST be replaced before the projector will operate normally. Press MODE/ENTER to dismiss the message.

1. Turn the power off and disconnect the projector from the power outlet. If the lamp is hot, avoid burns by waiting for approximately 45 minutes until the lamp has cooled.

2. Loosen the screw that secures the lamp cover on the side of the projector until the lamp cover loosens.

3. Remove the lamp cover from the projector.

• Do not turn the power on with the lamp cover removed.

• Do not insert your fingers between the lamp and the projector. The sharp edges inside the projector may cause injuries.

4. Loosen the screw that secures the lamp.

5. Lift the handle so that it stands up.

6. Use the handle to slowly pull the lamp out of the projector.

• Pulling it too quickly may cause the lamp to break and scatter broken glass in the projector.

• Do not place the lamp in locations where water might splash on it, children can reach it, or near flammable materials.

• Do not insert your hands into the projector after the lamp is  removed. If you touch the optical components inside, it could cause color unevenness and distortion of the projected images.

7. Lower the new lamp.

8. Tighten the screw that secures the lamp.

9. Ensure the handle is fully laid flat and locked in place.

• Loose screw may cause a bad connection, which could result in  Malfunction.

• Do not over tighten the screw.

10. Replace the lamp cover on the projector.

11. Tighten the screw that secures the lamp cover.

• Loose screw may cause a bad connection, which could result in malfunction.

• Do not over tighten the screw.

12. Connect the power and restart the projector.

Resetting the lamp timer

Do not reset the lamp timer if the lamp has not been replaced as this could cause damage.

13. After the start-up logo, press MENU/EXIT and then press / until the System Setup : Advanced menu is highlighted.

14. Press to highlight Lamp Settings and press MODE/ENTER. The Lamp Settings page displays.

15. Highlight Reset Lamp Timer and press MODE/ENTER. A warning message displays asking if you want to reset the lamp timer. Highlight Reset and press MODE/ENTER. The lamp time will be reset to "0".

JBL BASS 550 powered sub woofer test procedure

Equipment needed: The “Source” AM/FM turner/CD player with remote control, Function/signal generator/sweep generator.  

Multimeter.

Cable - Phono plugs (RCA) and speaker cables. 

RCA Y-cable

Subwoofer, General Function
1) Connect both right and left phono jack (RCA) inputs to signal generator and the “Source” Tape/Aux. input jacks. Use Y-cable if necessary from mono source.
2) Connect Bass550 subwoofer to the “Source” with 13 pin Din cable.

3) Plug in subwoofer, turn power switch on; red LED should light.
4) Turn on generator, adjust to 100 mV, 50 Hz.
5) Push “power” button on the “Source”, (display should now be active); press “Tape/Aux” button, adjust volume (on Source) so display reads “VOLUME 30”.
6) Turn up level control on subwoofer full clockwise.
7) LED on subwoofer should cycle to green; bass response should be heard and felt from port tube opening.

Subwoofer, Sweep Function
1) Follow steps 1-7 above, using a sweep generator as a signal source.
2) Sweep generator from 20Hz to 300Hz. Listen to the cabinet and drivers for anyrattles, clicks, buzzes or anyother noises. If any unusual noises are heard, remove driver and test.

Subwoofer, Driver Function
1) Remove one or both drivers from cabinet; remove + and - wire clips.
2) Check DC resistance of driver; it should be approximately 5.8 ohms.
3) Connect a pair of speaker cables to driver terminals.
Cables should be connected to an integrated amplifier fed by a signal generator. Turn on generator and adjust so that speaker level output is 4.0V.
4) Sweep generator from 20Hz to 1kHz. Listen to driver for any rubbing, buzzing, or other unusual noises.

System, General Function
1) Connect Bass 550 subwoofer to the “Source” with supplied 13 pin Din cable.
2) Attach all five satellite speakers to the supplied speaker cables, terminating in a molex connector plugged into the subwoofer.
3) Plug in Bass550 subwoofer, turn power switch on; red LED should light.
4) Push “power” button on the “Source”; (display should now be active).
5) Toggle “surround mode” button on front panel or with remote control until “NORMAL” appears.
6) Toggle “rear speaker” button on front panel until “REAR SPEAKERS” is displayed in upper left corner.
7) Adjust volume (on Source) so display reads “VOLUME 30”.
8) Using remote control, press “TONE” button.
9) White noise should be heard, cycling from Left, Center, Right and Rear speakers in succession.
10)Press “TONE” button again to halt test.

INFINITY RS-12 SUBWOOFER troubleshooting – Fuse blown – relay not closing

INFINITY RS-12 Troubleshooting; For all problems (except blowing fuses)

After amplifier removal from cabinet, pull back plastic cover to examine unit. It is usually not necessary to completely detach the cover from the amp assembly.
CHECK TO SEE THAT RELAYS ARE CLOSING NORMALLY AND CONTACTS ARE
CLOSING: (Power LED goes ON, two audible "clicks" are heard 2 - 5 seconds after power is turned on):

 1. Attach power cord, connect AC signal (with Y-cable) into low level inputs; 100 mV @ 100Hz or music signal. Turn UUT on.
To confirm Relay 101 (power supply) is functional, check voltage across relay coil (see drawing for location) for 19 - 21 VDC. Then check voltages across R105/R106. RS-10: 12 - 13 VDC; RS-12: 22 - 23 VDC. If voltage is considerably higher there is a short causing the entire power supply voltage to appear across R105/R106. Or if voltage is absent see "NEITHER RELAY IS CLOSING" below.
To confirm Relay 102 (speaker output) is functional, check voltage across relay coil (see drawing for location) for 19 - 21 VDC. Attach 2 - 4 O power resistor to output cable of UUT. Check voltage across R147 for less than 50 mVAC. Little or no voltage across R147 assures R102 contacts are closing normally. (See drawing for location of R147.) If voltage is absent from relay coil see "FIRST RELAY (RLA 101) IS CLOSING, SECOND RELAY (RLA 102) IS NOT CLOSING"

Neither relay is closing

1. Check to see if LED is on, if not check to see if line fuse is blown. Replace if necessary — if fuse blows again see section IV: "UNIT BLOWS FUSES". If line fuse is not blown and LED is not on, check all AC connections at terminals and condition of line thermistor (should have DCR of 9 - 12 O). Otherwise replace toroidal transformer if required.

2. If LED is on and 21 VAC is present at the amp board (blue & black wires), and if 19 - 21 VDC is present at Relay 101 coil but no "click" is heard and rest of unit does not energize, replace Relay 101.

3. If no DC voltage is present at Relay 101 coil, check DC voltage across C103/C105 for +/- 15 - 17VDC. If voltages are very low unplug ribbon connector to filter board and re-check. If voltage rises to correct value than one of two conditions exist: A. C102, C104 are shorted or defective (most likely), or B. There is a short on the filter board, probably IC 201 (LF 347N). Replace and re-test.
Note: IC sockets are recommended for the new IC's.

If after IC replacement only one correct voltage is present check/replace appropriate Zener diode (D108 for C103, D111 for C105). 4. If DC voltages across C103/C105 are correct and Relay 101 is not closing: A. Unplug ribbon cable attached to input board. B. Insert a 15k resistor into leads 5 & 8 of the unplugged female connector end. (See drawing) C. Turn on UUT. If Relay 101 still doesn't close, check condition of D130 with "diode check" function on DMM; if shorted, replace. If O.K. replace Q116. 5. If DC voltage is present at Relay 101 coil and if it still doesn't closes, replace Relay 101.

First relay (rla 101) is closing; second relay (rla 102) is not closing

1. Check for 21 volts across Relay 102 coil . If present, replace Relay 102.

2. If no voltage is present: Check DC voltage across R105/R106. If voltage is substantially higher than (12-13 volts for RS10; 22-23 volts for RS12) there is a short on the 16v circuit.

To troubleshoot

A. Unplug ribbon cable attached to input board.

B. Insert a 15k resistor into leads 5 & 8 of the unplugged female connector end.  

C. Turn on UUT, second relay may now turn on and R105/R106 voltages may be correct. If so, replace IC 201 on input board.

D. If voltage is still high check zener diode (D116 for R106), (D115 for R105) for voltage abnormalities. Forward bias of zener can be checked with "diode check" function on DMM in the circuit or by checking for +/- 16 volts across zeners when energized. If either diode is defective, replace.

3. If no voltage is present at Relay 102 and voltages are correct across R105/R106:

Check for +15-16 volts on pin 8 of IC 101 (LF 347N) on main amp board.

Check for +1.7 to 1.9 volts on pin 9.

Check for +8 volts on pin 10.
If any of the above voltages are abnormal

Check DC voltage across R116 (33KO). (See drawing for location) Less than 50mV should be present. If higher, relay will not energize. DC is coming through the amplifier section. Check and replace semiconductors as necessary.

If there is negligible voltage across R116, (normal condition) check junctions of Q102, Q103 with "diode check" function on DMM in the circuit. Replace if defective. If O.K., replace IC 101 (LF 347N) on main amp board.
If all voltages are correct on IC 101:

Check junction of D118 "diode check" function on DMM in the circuit. Replace if defective. If O.K., replace Q101.

Unit blows fuses

Two conditions are possible: UUT blows fuses instantly when power switch is thrown, or UUT blows fuses when power supply relay is energized (due to an input signal).

Unit blows fuses instantly with no input signal

Desolder, remove power supply wires from main amp board (blue & black). Replace fuse, power up unit again. If fuse blows, replace shorted toroidal power transformer.

Unit blows fuses immediately after first relay is energized

A. Problem is usually shorted output or driver transistor or diode semi-bridge on main amp board.

These consist of: 2SC 3856 / 2SA 1492 TO-218 package; BD 911/912 TO-220 package;  FEN 16 / FEP 16 TO-220 package

Note: First check condition of D102,103.

All junctions can be tested in the circuit with a "diode check" function on a DMM. If a short is found; however, remember some devices are in parallel and will have to be removed to confirm the short.

B. Occasionally the output transistors seem O.K. or after a replacements high currents will continue to blow fuses. The problem is probably with one of the biasing transistors Q104,105,106,107,108,109.
Recommended final inspection

Check for a burnt or deformed thermistor (attached to power cord plug & switch). Replace if defective. Make sure the toroidal transformer is tight and will not move easily by hand. Make sure the Phillips screws holding the main amp board (on the front of the faceplate) are tight. (Loose screws mean poor transistor heat sinking, possible premature failure). Make sure the correct line fuse is in place; RS-10: 3A, RS-12: 4A — (all ratings at 120v). Make sure the red, red/black output wires are still maintaining an airtight seal as they thread through the plastic amp cover.

High voltage generator circuit electronic project

ELECTRONIC PROJECT 

This high voltage generator was designed with the aim of testing the electrical breakdown protection used on the railways. These protection measures are used to ensure that any external metal parts will never be at a high voltage. If that were about to happen, a very large current would flow (in the order of kilo-amps), which causes the protection to operate, creating a short circuit to ground effectively earthing the metal parts. This happens when, for example, a lightning strike hits the overhead line (or their supports) on the railways.

This generator generates a high voltage of 1,000 V, but with an output current that is limited to few milliamps. This permits the electrical breakdown protection to be tested without it going into a short circuit state. The circuit uses common parts throughout: a TL494 pulse-width modulator, several FETs or bipolar switching transistors, a simple 1.4 VA mains transformer and a discrete voltage multiplier. P1 is used to set the maximum current and P2 sets the output voltage.

The use of a voltage multiplier has the advantage that the working voltage of the smoothing capacitors can be lower, which makes them easier to obtain. The TL494 was chosen because it can still operate at a voltage of about 7 V, which means it can keep on working even when the batteries are nearly empty. The power is provided by six C-type batteries, which keeps the total weight at a reasonable level. 

The 2x4 V secondary of AC power transformer (Tr1) is used back to front. It does mean that the 4 V winding has double the rated voltage across it, but that is acceptable because the frequency is a lot higher (several kilo-Hertz) than the 50 Hz (60 Hz) the transformer is designed for.

The final version also includes a display of the output voltage so that the breakdown voltage can be read. From a historical perspective there follows a bit of background information.

In the past a different system was worked out. Every high-voltage support post has a protection system, and it isn’t clear when the protection had operated and went into a short-circuit state due to a large current discharge.

Since very large currents were involved, a certain Mr. Van Ark figured out a solution for this. He used a glass tube filled with a liquid containing a red pigment and a metal ball. When a large current discharge occurred the metal ball shot up due to the strong magnetic field, which caused the pigment to mix with the liquid. This could be seen for a good 24 hours after the event. After a thunder storm it was easy to see where a discharge current took place: one only had to walk past the tubes and have a good look at them.

Unfortunately, things didn’t work out as expected. Since it often took a very long time before a discharge occurred, the pigment settled down too much. When a discharge finally did occur the pigment no longer mixed with the liquid and nothing was visible. This system was therefore sidelined, but it found its place in the (railway) history books as the ‘balls of Van Ark’.