Ensoniq FIZMO: Replacing the Regulator
Brought to you by Muzik Elektronix enr.

With the kind permission of the original author, Rev. Norm Vogel.

 

 

What follows is the procedure to repair the well-known regulator failure problem on the FIZMO.

WARNING
This procedure should only be done by someone who is familiar with soldering circuit boards. Excessive heat can damage the parts, as well as the circuit board! I have done this procedure and it worked for ME! Please note that I am not responsible if you do something wrong any damage your synth or the components. (disclaimer!)

I suggest that you read this tutorial thru several times (& PRINT it) before attempting this procedure!
Rev Norm Vogel, the author

 

 

 

 

 

Parts / Tools Needed


Parts:

1 - rectifier MC7805CT @ 1.5 amp (see below for supplier)

2 - 1uf Tantalum Capacitors (Radio Shack # 272-1434A (1.0 MFD 35WVDC maximum)

1 - Screw / washer / lockwasher / nut (to hold down the regulator) I recommend a 4-40 1/2" Steel Machine Screw.

If you are using the ORIGINAL power supply, you SHOULD replace it with a Radio Shack # 273-1611 (9VAC 1300ma). The box says "Nintendo Power Adapter", but will work with the Fizmo -- even it's plug is the correct size!


Tools:

Low-wattage soldering iron (& solder)

Heat Sink Compound (Radio Shack # 276-1372; to dissipate the heat).

1 or 2 Heat Sinks (Radio Shack # 276-1567A - to prevent the components from over-heating when solding)

"Extra Hands" (to hold the board and leads; a VERY handy tool!
(Radio Shack # 64-2063)

High intensity light (These parts are SMALL!)

Drill and small drill bits

Small needle-nose pliers

 

The regulator can be purchased at:
  A complete repair kit is also available at:
EPR Electronics
690 California Avenue
Middletown, NY 10940

http://www.eprelectronics.com
phone: 845-343-1237
fax: 845-343-7663
e-mail: info@EPRelectronics.com		  

Muzik Elektronix enr.
347 Brooks
Sherbrooke, QC
Canada
J1H 4Y2

http://www.muzikelektronix.com
phone: 819-346-0394
e-mail: boutik@muzikelektronix.com

 

Note: the 1.5 Amp Rectifier is hard to get. See Scientific Calculations: Heatsink in our Articles section for a workaround. -Stéphane Jutras, Muzik Elektronix tech.


The cost is about $3.00. Unfortunately, they have a $15 minimum on parts orders! To "make up the cost", you can see if they have the capacitors, too! (They claim that you can use electroylic caps instead, but a synth repairman said that electrolytics will "cause more problems").


Look at it THIS way -- after paying all that hard-earned cash for a FIZMO, a mere $15 isn't much to spend to keep it from "frying"!

The Repair Procedure

 

First, turn your Fiz upside-down (with the keys facing you). It's a good idea to put something (like a small 2 x 4 piece of wood) under the sides, to keep the knobs and keys from getting damaged. (This keeps 'em off the ground). Next, remove all the screws from the underside; some of 'em are real BUGGERS! LOL!


Remove the plate that has the rubber feet in the corners. It should like like the photo below. Note the main board and the location of the regulator.





Remove the screws holding the main board (including the ones in the back, that are between the midi and output jacks). Gently lift the board up. Now comes the hardest part. The regulator is (usually) held by something that looks like a "pop rivet". The rivet must be removed.



I've found that the best way is to hold the board on edge (see picture); hold the regulator side of the rivet with your fingers (or a pair of pliers). Next, use a drill SLIGHTLY larger than the hole in the bottom of the rivet. IMPORTANT!!! hold the board FIRMLY, so that it doesn't snap! (OUCH!). At this point, the heat sink should fall out; save it.



After you've removed the rivet, hold the board vertically (it's best to use a Radio Shack "Extra Hand" for this). Slide a small needle-nosed pliers down and hold ALL THREE of the regulator pins. Unsolder it from underneath the board. DON"T apply too much heat; keep the iron "moving" back and forth between the pins, so that they all heat up together. When the solder is melted, use the pliers to pull the leads up from the board.



Next, find a small piece of wire. Again, heat each hole, one at a time, and stick the wire into it from the top; this will open the holes. (Or, you can use a solder extractor).


Peel the material off the underside of the old regulator and save it. Take the NEW regulator and lay it on the board so that the mounting holes line up. Again, slide the needle-nose pliers in (next to the regulator) so that the leads that protrude from the pliers are lined up with the 3 holes in the circuit board. Still holding the leads with the pliers, bend them downward at a 90-degree angle. (IMPORTANT: Don't use the old regulator as a guide, as the holes don't quite line up!).



Lay the heat-sink on the circuit board. Take the material you removed from the old regulator and put "heat sink" paste on both sides of it (this will help remove the heat from the regulator) and place it on the heat sink.


Next, insert the screw into the top hole of the regulator, and CAREFULLY insert each lead into the circuit board hold (use the needle-nosed pliers; it helps!). At this point, the new regulator should be in the same place as the old one.


Underneath the board, slip on (in this order) the washer, lock washer, and the nut. Hold the nut with pliers, and screw the screw in TIGHTLY, but don't over-do it! It should be firmly mounted. (The lock washer is to help "snug" it).



It's a good idea at this point to clip the heat sink on each lead (on top of the board) while soldering it on the underside of the board; this will "absorb" the heat, so that it doesn't burn out the regulator. When all three leads have cooled, clip off any excess wire on the underside of the board.



Now comes the "delicate" part -- soldering on the capacitors. See the diagram to determine the positive and negative leads. (This is where the strong light comes in; these things are TINY!!!!). It is important that you have the leads noted correctly!!! (You might want to take a marker and blacken the negative leads).





The next step is to solder the POSITIVE leads of each cap(acitor) to the 2 end leads of the regulator, and the two NEGATIVE leads to the CENTER pin.


Hold one cap's lead with the pliers, and bend about 1/8" at a 45-degree angle. Do this to the other one. I found that it's best to solder the POSITIVE leads FIRST; this will anchor them, so that when you solder the 2 negative leads to the pin, the caps are being held by their OTHER lead.


Use the Radio Shack "Extra Hands" to hold the cap, and adjust it so that the 45-degree part of the positive lead touches the regulator. Solder it. Then, repeat the same with the other cap. Then, it's easy to bend both NEGATIVE leads so that they touch the center pin. Solder these as well, being careful not to overheat anything!

 


NOTE: Kevin Lightner has pointed out to me that the cap leads in the picture above are much too long! They should only be HALF that length because, when assembling/disassembling the unit, the leads could bend, & short out each other, or against OTHER parts! Please make 'em SHORTER!

IMPORTANT ! ! ! At this point, make sure you soldered the plus and minus leads correctly!!! Recheck them against the diagram. If you've done it correctly, the printing on the caps should face the OPPOSITE directions! (In other words, you should NOT see the printing on both facing the same direction!!!!)


Use a Q-tip to remove any of the heat-sink grease. Screw the board back down to the synth. If needed, gently bend the caps, so that they are not directly above the regulator (away from it's heat).


Connect the power supply and turn on the synth. Test it for sounds. Let it sit for about an hour or two; the regulator should be WARM to the touch, but not HOT!


If everything is ok, screw the bottom back on. CONGRATS! You've DONE IT!
" A Happy Fizmo ! ! !"



For a copy of this procedure in GERMAN, pls click HERE!



Text and pictures copyright© by Norm Vogel

 

-Reproduced with permission-