Alesis DG8 User manual
Alesis DG8 Service Manual V1.00a ii 01/19/07
Preface
This document is intended to assist the service technician in the operation, maintenance and repair of the DG8
Digital Grand Piano. Together with the DG8 Reference Manual, this document provides a complete description of the
functionality and serviceability of the DG8. Any comments or suggestions you may have pertaining to the document are
welcome and encouraged.
READ THIS!
In addition to any purchase price that Alesis may charge as consideration for Alesis selling or
otherwise transferring this service manual (“Manual”) to you, if you are not a service and repair
facility (“Service Center”) authorized by Alesis in writing to be an authorized Service Center,
Alesis sells or transfers the Manual to you on the following terms and conditions:
Only Service Centers authorized by Alesis in writing are authorized to perform service and repairs covered
by an Alesis warranty (if any), and transfer of the Manual to you does not authorize you to be an
authorized Service Center. Therefore, if you perform, or if the Manual is used to perform, any
service or repairs on any Alesis product or part thereof, any and all warranties of Alesis as to that
product and any service contract with Alesis for that product shall be voided and shall no longer
apply for such product, even if your services or repairs were done in accordance with the Manual.
All service or repairs done by you or with reference to the Manual shall be solely your responsibility, and
Alesis shall have no liability for any such repairs or service work. All such service or repairs are
performed at the sole risk of the person performing the service or repairs. You agree that all such
work will be performed in a competent, professional and safe manner at all times and to indemnify and
fully hold Alesis and its successors and assigns harmless in the event of any failure to so perform.
Your purchase of the Manual shall be for your own ultimate use and shall not be for purposes of resale or
other transfer.
As the owner of the copyright to the Manual, Alesis does not give you the right to copy the Manual, and
you agree not to copy the Manual without the written authorization of Alesis. Alesis has no obligation to
provide to you any correction of, or supplement to, the Manual, or any new or superseding version thereof.
Alesis shall have the right to refuse to sell or otherwise transfer repair parts or materials to you in its sole
discretion. You shall not use, sell or otherwise transfer spare or replacement parts supplied by Alesis to
you (i) to repair or be used in products manufactured for or by third parties or (ii) to any third parties for
any purpose.
You shall not make any warranties or guarantees with respect to the products of Alesis or the use thereof
on behalf of Alesis or in your own name.
The foregoing describes the entire understanding related to sale or transfer of the Manual to you, and no
other terms shall apply unless in writing signed by an authorized representative of Alesis.
All Trademarks are property of their respective companies.
Warnings
TO REDUCE THE RISK OF ELECTRIC SHOCK OR FIRE, DO NOT EXPOSE THIS PRODUCT TO WATER OR
MOISTURE.
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
The arrowhead symbol on a lightning flash inside a triangle is intended to alert the user to the presence of
un-insulated "dangerous voltage" within the enclosed product that may be of sufficient magnitude to
constitute a risk of electric shock to persons.
The exclamation point inside a triangle is intended to alert the user to the presence of important operating,
maintenance and servicing instructions in the literature which accompanies the product.
Alesis DG8 Service Manual V1.00a iii 01/19/07
REPAIR BY ANY PERSON OR ENTITY OTHER THAN AN AUTHORIZED ALESIS SERVICE CENTER
WILL VOID THE ALESIS WARRANTY.
PROVISION OF THIS MANUAL DOES NOT AUTHORIZE THE RECIPIENT TO COMPETE WITH ANY ALESIS
DISTRIBUTOR OR AUTHORIZED REPAIR SERVICE CENTER IN THE PROVISION OF REPAIR SERVICES OR TO BE OR
MAKE REPAIRS AS AN AUTHORIZED SERVICE CENTER.
ALL REPAIRS DONE BY ANY ENTITY OTHER THAN AN AUTHORIZED ALESIS SERVICE CENTER SHALL BE
SOLELY THE RESPONSIBILITY OF THAT ENTITY, AND ALESIS SHALL HAVE NO LIABILITY TO THAT ENTITY OR
TO ANY OTHER PARTY FOR ANY REPAIRS BY THAT ENTITY.
CAUTION
Danger of explosion if battery is incorrectly replaced.
Replace only with the same type or equivalent type
recommended by the equipment manufacturer. Discard
used batteries according to manufacturer's instructions.
Battery Manufacturer: Panasonic/Matsushita
Type: BR2325
Rating 3V, 5mA
Uwaga
Wystepuje ryzyko eksplozji jezeli bateria zostanie
wymieniona w nieodpowiedni spos¢b. Wymieniac tylko
uzywajac tego samego typu, lub zamiennika
rekomendowanego przez producenta.
Producent Bateri:Panasonic/Matsushita Typ: BR2325 3V,
5 mA
VARNING!
Explosionsrisk om felaktigt batteri installeras.
Ers„tt endast med batteri av samma eller motsvarande
batterityp som rekomenderas av enhetens tillverkare.
Batteritillverkare: Panasonic/Matsushita Typ:
BR2325
Data: 3V, 5mA
VAROITUS
Paristo voi räjähtää, jos se on virheellisesti asennettu.
Vaihda paristo ainoastaan valmistajan suosittelemaan
tyyppiin. Hävitä käytetty paristo valmistajan ohjeiden
mukaisesti.
Varnig
Explosionsfara vid felaktigt batteribyte. Använd samma
batterityp eller en eller en ekvivalent typ som
rekommendaras av tillverkaren. Kassera använt batteri
enligt fabrikantens instruktion
Alesis DG8 Service Manual V1.00a iv 01/19/07
Advarsel!
Lithiumbatteri. Eksplosionsfare ved fejlagtig håndtering.
Udskiftning må kun ske med batteri af samme fabrikat og
type. Levér det brugte batteri tilbage till leverandøren
Caution,
Danger of fire or electrocution if fuse is incorrectly
replaced. Replace only with the same type or equivalent
type recommended by the equipment manufacturer.
Type 5x20mm F 10A 250V. (F = standard blow)
Alesis DG8 Service Manual V1.00a v 01/19/07
Safety Suggestions
Carefully read the applicable items of the operating instructions and these safety suggestions before using this
product. Use extra care to follow the warnings written on the product itself and in the operating instructions. Keep
the operating instructions and safety suggestions for reference in the future.
1. Power Source. The product should only be connected to a power supply which is described either in the
operating instructions or in markings on the product.
2. Power Cord Protection. AC power supply cords should be placed such that no one is likely to step on the
cords and such that nothing will be placed on or against them.
3. Periods of Non-use. If the product is not used for any significant period of time, the product's AC power
supply cord should be unplugged from the AC outlet.
4. Foreign Objects and Liquids. Take care not to allow liquids to spill or objects to fall into any openings of
the product.
5. Water or Moisture. The product should not be used near any water or in moisture.
6. Heat. Do not place the product near heat sources such as stoves, heat registers, radiators or other heat
producing equipment.
7. Ventilation. When installing the product, make sure that the product has adequate ventilation. Improperly
ventilating the product may cause overheating, which may damage the product.
8. Mounting. Do not place this product on an unstable cart, stand, or table. The product may fall, causing
serious personal injury and serious damage to the product. Use only with cart, stand, or table recommended
by the manufacturer or sold with the product. The combination of the product and stand should be moved
carefully. Quick movements, excessive force on uneven surfaces may overturn the combination which may
damage the product and stand combination. Follow the manufacturers instructions when installing the
product and use mounting accessories recommended by the manufacturer.
9. Cleaning. The product should only be cleaned as the manufacturer recommends.
10. Service. The user should only attempt the limited service or upkeep specifically described in the operating
instructions for the user. For any other service required, the product should be taken to an authorized
service center as described in the operating instructions.
11. Damage to the Product. Qualified service personnel should service the unit in certain situations including
without limitation when:
a. Liquid has spilled or objects have fallen into the product,
b. The product is exposed to water or excessive moisture,
c. The AC power supply plug or cord is damaged,
d. The product shows an inappropriate change in performance or does not operate normally, or
e. The enclosure of the product has been damaged.
Alesis DG8 Service Manual V1.00a vi 01/19/07
General Troubleshooting
While this manual assumes that the reader has a fundamental understanding of electronics and basic troubleshooting
techniques, a review of some of the techniques used by our staff may help.
ΠVisual Inspection - A short visual inspection of the unit under test will often yield results without the need of complex
signal analysis (burnt, or loose components are a dead giveaway).
ΠSelf-Test - Alesis products that utilize microprocessor control contain built in test software which exercises many of the
units' primary circuit functions. Self-test should always be done following any repair to ensure basic functionality.
ΠEnvironmental Testing - Applying heat and cold (heat gun/freeze spray) will often reveal thermally intermittent
components (Clock crystals, ICS and capacitors are particularly prone to this type of failure).
ΠBurn in Testing - Leaving a unit running overnight often reveals intermittent failures such as capacitors that begin to leak
excess current after a significant amount of time.
ΠCable Checks - Wiggling cables can reveal intermittent failures such as loose cables or poorly soldered headers.
Remember to check power supply cables as well.
ΠFlexing the PC Board - Poor solder joints and broken traces can often be found by pressing the PC Board in various
places.
ΠTapping Components - Sometimes tapping on a component (particularly crystals) will cause it to fail.
ΠPower Down/up - Turning the unit off and back on rapidly several times may reveal odd reset and/or power supply
failures.
ΠReset Threshold - A Variac (variable transformer) can be used to check reset threshold levels. This can be particularly
useful in helping customers with low line problems.
ΠCompressors - Using a compressor/limiter is often helpful when attempting to solve low level noise problems, as well as
assisting with DAC adjustments.
ΠSweep Tests - Sweep generators are very useful in checking the frequency response envelopes of anti-aliasing filters.
ΠPiggybacking - Piggybacking ICS is particularly useful when troubleshooting large sections of logic. This is especially
true when working with older units.
ΠAssembly/Disassembly Organization - When removing assemblies, organize screws and
clips with the assemblies that they were removed from. Organizer trays save a lot of time
during re-assembly since similar screws and clips will not be mixed with each other.
G8 ASSEMBLY INSTRUCTIONS:
Revision B.
July 23, 1999
Alesis DG8 Service Manual V1.00a 7 01/19/07
G8 ASSEMBLY INSTRUCTIONS
G8 SUBASSEMBLIES:
•END CAPS
•TOP EXTRUSION
•BOTTOM PANEL
•UNIT ASSEMBLY
END CAP ASSEMBLY
1. Remove liner from foam gasket (9-34-0008 for right and 9-34-0009 for left) and
apply to metal bracket (5-07-0008 for right and 5-07-0009 for left) side opposite of
the screw tabs, centering the punched holes in the gasket with those in the bracket.
Picture 1
2. Attach Key-Filler (left 9-15-0139 and right 9-15-0140) using two screws P/N 5-00-
1013 (# 8x1/2” PPB Hilo), refer to picture 2.
Alesis DG8 Service Manual V1.00a 8 01/19/07
Use 10in/lb torque making sure alignment pins on key filler enter holes in bracket
next to mounting holes.
3. Attach End Cap to metal bracket/key filler assembly, (refer to Picture 2) use 10
screws P/N 5-00-1013 @ 10in/lb torque. Make sure alignment pins enter holes in
bracket near mounting holes.
4. Wrap assemblies in sheet foam and stage at final assembly.
Picture 2
TOP EXTRUSION ASSEMBLY
1. Place two strips of aluminum tape P/N 7-12-0035 (left) 7-12-0036 (right) to bottom
side
of Top Extrusion, refer to Picture3. Note longer strip goes on the left and shorter on
the
Right.
Alesis DG8 Service Manual V1.00a 9 01/19/07
Picture 3
2. Apply foam strip to edge of all bezels where tab extends into extrusion.
3. Install Graphic EQ (9-10-0033), Level Control (9-10-0033), Display (9-10-0034)
and Keypad Select (9-10-0032) Bezels inside bottom of Top Extrusion, note correct
orientation and placement. Bezels slide into the top rail and then snap in the bottom
rail.
4. Attach bezels BY HAND using 12 screws P/N 5-00-0133 (6-32 x ¼ PPZ TT), tighten
@
6 in/LB torque.
5. Install rubber keypads as shown in Picture 4.
A) 9-30-0012 Keypad Harpsi/Clav
B) 9-30-0011 Keypad Elec. Piano-2
C) 9-30-0010 Keypad Piano2
D) 9-30-0008 Keypad Piano1
E) 9-30-0009 Keypad Up/Down
F) 9-30-0014 Keypad Tune
Alesis DG8 Service Manual V1.00a 10 01/19/07
Picture 4A
+
Picture 4B
6. Install E/Q Keypad (9-30-0013) to E/Q PCB
7. Install Slider EQ PCB assembly (9-79-0089) onto Top Extrusion, make sure LED
is aligned with hole, use 12 screws P/N 5-00-0138 (6/32 X 3/8 PPZ Hilo) @ 6 in/LB
torque.
8. Install Keypad PCB Assembly (9-79-1347) onto Top Extrusion uses 10 screws
P/N 5-00-0138 @ 6 in/lb. torque. Orient header towards LCD display bezel as shown
in Picture 5. Make sure alignment pins are centered in holes in PCB.
Picture 5
Alesis DG8 Service Manual V1.00a 11 01/19/07
9. Remove protective plastic from LCD display then snap into LCD Bezel, orient J1
header towards Slider EQ PCB. Make sure LCD display is straight. Refer to Picture
6.
Picture 6
10. Turn Top Extrusion right side up. Make sure there is not dust or debris on Display.
10. Install clear Bezel overlay into Display Bezel (9-10-1135). Note correct orientation.
11. Install 10 fader caps (9-15-1179). Leave Graphic EQ sliders centered and
Level/Volume
down.
TOP PANEL ASSEMBLY
1. Paint routed recess in top panel BLACK.
2. Attach “Voo-doo” sonic brace with assembly glue and tape with glue block. Allow to
cure.
3. Slide Top Extrusion (9-08-0017) onto Top Panel (P/N 9-05-0002) on edge closest to
Port Tube holes. Make sure holes are aligned and Extrusion is fully seated.
1. Attach Top Extrusion assembly to Top Panel using (8) screws P/N 5-00-0119 (#8 x
3/8 PFZ Hilo) @13 in/LB torque. Refer to Picture 7. Attach outermost screws first.
3. Place Front Baffle P/N 9-07-0003, against vertical leg of Top Extrusion and align
screw holes. Orient vinyl black side toward Top Extrusion, use 8 screws P/N 5-00-
0814
@ 15 in/LB torque. Use a 6” long #2 Phillips bit.
Alesis DG8 Service Manual V1.00a 12 01/19/07
Picture 7
4. Slide Rear Extrusion onto Top Panel assembly (Make sure the Rear Extrusion is fully
seated onto the Top Panel), use 8 screws P/N 5-00-0120 @ 13 in/lb. torque. Refer to
slots milled into lower leg to guide and align the 6” #2 Phillips bit. Attach outermost
screws first.
5. Attach adhesive ring to inside surface of top panel at woofer hole.
6. Attach Woofer Mount Rings to top panel using 4 (2 each) screws P/N 5-00-0120 at
mounting tabs.
7. Attach Woofer Mounting Ring to Front Baffle using 4 (2 each) screws P/N 5-00-0833
@ 13 in/LB torque.
Picture 8A Picture 8B
7. Install Left End Panel (has an “L” routed into the side) using (2) screws P/N 5-00-
0814
@ 25 in/LB torque through Front Baffle and (1) through Rear Extrusion closest to
Alesis DG8 Service Manual V1.00a 13 01/19/07
bottom. Do not install upper-rear external End Cap screw. Use black assembly glue.
8. Install Right End Panel (refer to Picture 8) using 3 screws P/N 5-00-0814 @ 25 in/lb.
Picture 9A Picture 9B
9. Install Center Brace p/n 9-07-0002 inside middle of Top Panel; use 4 screws P/N 5-
00-
0814 # 8 x 1 ¾ PTB SMA 2 through the Front Baffle and 2 through the Rear
Extrusion.
Use 25-in/lb torque. Use black assembly glue.
10. Install Center Baffle “λ” Baltic Birch P/N 9-07-0017 against Center Brace and hot
glue
in place using sealant along all edges and seams.
11. Install rubber speaker grill grommet (8) P/N 9-15-0187 to Top Panel, insert so it is
flush
with Top Panel speaker grill recess. Make sure grommet is the correct kind. Refer to
Picture 10A and 10B.
Picture 10A No line in the middle. Picture 10B No coarse finish.
Alesis DG8 Service Manual V1.00a 14 01/19/07
12. Apply sealant on all seams, corners and on top of screws inside Top Panel.
13. Apply black carpenters glue to outside diameter of Port Tube (see Picture 11A).
and spread with finger. The tubes are positioned in the counterboard hole adjacent to
the
Front Baffle. Make sure Port is fully seated in the Top Panel, does not drop when
released and that open edge of port tube is dyed black.
Picture 11 A Picture 11 B
TILT BOTH PORT TUBES TOWARDS FRONT BAFFLE
14. Apply hot glue to sides of Port Tube Braces and locate as shown in Picture 11 B
then
glue both braces along mating edges to ensure thorough contact.
15. Apply hot glue to Brace and place between Tweeter hole and Mounting ring right
and
left as shown below.
Picture 12A Picture 12B
16. Install cable guides on Front Baffle interior under the slots used to route cabling,
and line slots with foam strips.
Alesis DG8 Service Manual V1.00a 15 01/19/07
17. Install cable guides along Front Baffle exterior by wire relief.
18. Apply strip of foam on exposed end of end of λboard and seal wire slots.
19. Install G8 Amp Sil Pad P/N 9-15-0199 inside Rear Extrusion, align to three studs.
See Picture 14A.
20. Install Amplifier PCB assembly P/N 9-79-1380 on top of Sil Pad, use 6 split- lock
washer P/N 5-01-0038 and 6 8/32 hex nuts. Make sure no foreign matter (i.e., wood
or metal particles) are between Amp-sil pad (5-02-8327) and Rear Panel.
Apply using 13 in/LB of torque.
Picture 12 Picture 13
Picture 14A Picture 14B
21. Attach Power Supply to Rear Extrusion using 1 screw 8-32 x ½ ppb, and to front
baffle
using (2) screws P/N 5-00-0833 at 13 in /LB
22. Install Power Supply PCB P/N 9-79-B501 into Top Panel Assembly next to the
Left End Panel as shown in Picture 15B. Push corner Grommet to facilitate
installation.
23. Attach Power Supply to mounting tab using 2 (# 6-32 x ¼” Undercut FH) screws
and
to Rear Extrusion using 1 (8-32 x ½ PPB) screw.
Alesis DG8 Service Manual V1.00a 16 01/19/07
Picture 15A Picture 15B
24. Attach cables to woofer (4-74-0021) and tweeter (4-74-0022). Make sure that
tweeter
cables are installed with the white wire to the unpainted terminal of the tweeter and
the
black wire attached to the terminal painted in RED. INSERT ALL THE WAY!!
The woofer terminals are of different size, one terminal is smaller.
25. Turn Top Assembly over.
26. Apply adhesive ring set P/N 7-12-0034 to woofer and tweeter openings on Top
Panel.
27. Install woofer speaker (7-02-0016) using 16 screws P/N 5-00-0002, four (8) for each
woofer @ 10 lbs./in torque.
28. Install both tweeters (7-02-0018) using 6 screws P/N 5-00-0139 and with splitlock
washer P/N 5-01-0031 @ 10 lbs./in torque.
29. Install the following Top Panel assembly cables as follows:
•Cable 6-pin 4-19-0607 (32in) from Amp Left to Interface J11. Route along
bottom
of port tube.
•Cable 6-pin 4-19-0607 (34 in) from Amp Right to Interface J8.
•Cable 6-pin 4-19-0616 (48 in) from Amp Right to Amp Left.
•Cable 6-pin 4-19-0615 (11in) from Power Supply to Amp Left.
•Cable 8-pin 4-19-0805 (20in) from EQ/Slider to Interface J9.
Route J4 (Amp to Amp cable) along Rear Extrusion. Refer to Picture 16B
Tie all cables using Cable Clamp (Folding Tab) 12 total, P/N 9-03-0069.
30. Turn Top Assembly over.
Alesis DG8 Service Manual V1.00a 17 01/19/07
Alesis DG8 Service Manual V1.00a 18 01/19/07
31. Plug Top Assembly cables into Interface Board. Refer to Picture 16A.
Slider/EQ ÆJ9
Amp Left ÆJ11
Amp Right ÆJ8
Phones ÆJ7
Power Supply ÆJ13
32. Install Shield Main/Interface Assembly on the Rear Extrusion; use 6 screws P/N 5-
00-
0833 @ 15 in/LB torque.
33. Remove phono cliffnuts from Main PCB.
34. Install Main PCB P/N 9-79-1346, use 3 screws P/N 5-00-0075 @ 15 in/lb. torque and
2 screws P/N 5-00-0006 on Main PCB’s PCMCIA card.
35. Reinstall cliff nuts on jacks at Rear Extrusion. Tighten appropriately.
36. Plug Interface cables to Main PCB as follows:
NOTE ORIENTATION OF PIN #1
INTERFACE MAIN
J6 J13
J5 J12
J1 J17
J4 J16
J3 J11
J2 J15
Picture 16A Picture 16B
37. Install fiberglass foam on Top Panel Assembly as shown in Picture 16A/B.
Insulation Fiberglass 100 x 110 P/N 7-07-0033 by the side panel.
Insulation Fiberglass 100x510 (2) P/N 7-07-0037next to Rear Extrusion and Front
Baffle.
Insulation Fiberglass 165x510, P/N 7-07-0036 across Bottom Panel. Apply as shown
in
Picture 16B.
Picture16A Picture 16B
38. Place assembly in Burn-In fixture, attaches cables, and set timer for 30 seconds.
Alesis DG8 Service Manual V1.00a 19 01/19/07
BOTTOM PANEL ASSEMBLY
1. Place keybed upside down, keys facing the front as shown in Picture 12A.
2. Plug Keyboard cables (2) P/N 4-18-1421 as shown in Picture 12B.
Picture 12A Picture 12B
2.5 Apply 11 Felt spacers P/N 5-04-0053 to keybed at tapped holes.
3. Route keyboard cables safely away from mounting points.
3.5 Apply jet melt glue across header to glue cable to PCB assembly.
Inspect bottom panel for defects.
4. Attach Bottom Panel P/N 9-05-0814 to keybed; use 11 screws P/N 5-00-1035 in
locations where keybed bracket holes align with Bottom Panel inserts. Use 10 in/LB
torque.
4.5 Check Front Extrusion for defects.
Alesis DG8 Service Manual V1.00a 20 01/19/07
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