Lindos LA100 Supplement

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Lindos Electronics, Saddlemakers Lane
Melton, Woodbridge, Suffolk, IP12 1PP, U
K
Lindos Electronics Application Notes
Copyright Lindos Electronics
LA100 Application Note 32:
Fitting the LA100 Silver Upgrade (Linear PSU)
Note: Only fit this modification to LA101 or LA102 with a transformer (NOT a black
switch-mode power supply). These instructions apply to issue 4 and 5 LA100 top boards.
This kit is to be fitted by competent engineering personnel. If you have any queries,
contact Lindos for advice.
While fitting the kit, static electricity precautions should be observed.
Check kit contents:-
• 2 x Chassis
• 2 x Sets of single covers
• 2 x Rear panels
• 2 x Front panels
• 1 x Set of LA101 front and rear labels
• 1 x Set of LA102 front and rear labels
• 2 x Fuse holders
Fitting the upgrade:-
• Remove covers and place to one side.
• Unplug the cable forms and unscrew the circuit boards and place in a rack.
• Fit the switch to the LA101 bottom board, this is found on Iss.2 boards or above
only. This is marked S2 on some boards or with a centre ground/floating diagram on
others. Refer to photo below. Issue 3 and Issue 4 V2 require modifying.
• 2 x Fuse holder boots
• 2 x 1A fuses
• 2 x 150mm length of brown cable
• 1 x Switch
• 2 x D-type sub PCB connectors
• 2 x RS232 leads
• 2 x Cable ties
LA101 Issue 4
–
V2
LA101 Issue 3
LA101 Issue 4 – V1
DO NOT MODIFY

Lindos Electronics Application Notes
Copyright Lindos Electronics
1. Using a scalpel, cut the track that links the toggle switch S2 to the left fuse bracket
of F3. Refer to the diagram below as necessary.
2. Link the right leg of the switch to the right side of resistor (R6 or R7) below it using
kynar wire (or a suitable alternative) as shown below.
3. Using a multimeter set to ohms, place one probe on the grounding point for the
chassis (found on the right hand edge of the board after the inductor L1) and the
other probe on the centre pin of the switch S2. With the switch to the right (as
shown below – ‘floating’ setting) you should measure 10kO; with the switch to the
left ~5O should be measured.
• Carry out the lithium-ion upgrade (Application Note 23) until the instruction ‘Check
the number on the diode….’, returning to it later when specified in these instructions.
• Remove the DIN connectors from the top boards and replace with the D-type sub
PCB connectors. Use the diagram below for the pin placement of the D-type sub
PCB connectors.
• Do the following procedures for each unit separately. Remove the front panel from
the chassis and place to one side. Remove the rear panel and discard. Remove the
XLR sockets, mains filter, fuse holder (if present) and the BNC sockets (LA102 only)
and retain.
LA101 Issue 4 V2 afte
r modification
LA101 Issue 3 after modification

Lindos Electronics Application Notes
Copyright Lindos Electronics
• Take the new chassis and check that the mains filter fits; the hole may need to be
filed. This is best achieved by gradually filing all four sides of the hole to ensure that
the bolt holes remain aligned. Clean burs from the edges and clean off filings. Place
the relevant LA101 or LA102 back label on the chassis. Fit the BNCs (102 only) and
XLRs and screw in the mains filter, fit the fuse holder or add a new one.
Fix the fuse holder to the chassis using the nut provided, solder the brown wire, after
placing through fuse holder boot first, from the mains filter and solder to one tag on the
fuse holder. Take the length of brown wire and solder to the other fuse holder tag and slot
through the fuse holder boot also. This will be soldered to the board – see section 9. Slot
the fuse holder boot onto the fuse holder and tighten in place with the cable tie. Take the
1A fuse and place into the fuse holder slot and screw this into the fuse holder attached to
the chassis. Finally screw in the new rear panel.
• From the old front panel remove the LCD display, glass, keypad assembly and
jacks. The jacks are removed by peeling away the label to allow the unscrewing of
the jack nuts. These items are retained except the brown front panel and buttons.
Take the new front panel and remove and discard the grey button support and screw
in the retained keypad assembly – key mat and keypad PCB. Fit the retained jacks
with the washer and nut – looking from the rear, the red and white ground wires
should be in the top left corner. Place a front label on the panel and check that the
buttons do not stick – change any that do. Clean the glass and place into the panel.
Clean the LCD and screw into the panel. The assembled front panel can now be
screwed onto the chassis.
• Solder the live (brown) and neutral (blue) wires to the transformer connections on
the bottom of the top board (see photo above) and then screw the board to the
chassis, connect the front panel cables to the top board. Screw on the bottom board
and connect the top and bottom boards with the cable form. Go back to Application
Note 23 to finish the upgrade procedure.
• Test the units by running a self-test.
GG 07.03.2007