Sega G-80 Manual de usuario descargar pdf

Mongo’s*SimpleSegaG80

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VectorMods



(ElectrohomeG08803)

*actuallystolenfromvariousotherauthors 

©Copyright2008PatrickJ.Co oke.NoaffiliationwithSegaorElectrohomeisexpressedorimplied.

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DISCLAIMER: Working on monitors can be dangerous. You are dealing with high voltage

equipment, as well as a potential risk of implosion of a picture tube. I take no responsibility for

damage to yourself, others, or your equipment. If you are unfamiliar with high voltage systems DO

NOT put yourself in danger. Get someone qualified to work on it and watch them and learn.

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Sega Vector games are becoming increasingly rare.This is usually blamed on the notorious

reputationof the Electrohome G08 monitor to catch fire.Although the veryearlyversionsof

thismonitordidearnthereputationlegitimately,themajorityofthemonitorswerenotprone 

to this failure.Simply browsing available technical and troubleshooting articles reveals there

are three contributing factors to game failure that anyone can correct with little or no

troubleshootingknowledgeandaminimumoftools.Thethreeare:

1‐ DeflectionTransistors.TheDeflectiontransistorsfortheG08 aregettingVERYdifficult

tofind.Anythingthatcanbedonetoprolongtheirlifeshouldbedone.Inthefirstpart

of this tutorial, we will enhance the heat transfer ability of the transistors (heat kills

electronics)withsomesimplemaintenance,cleaning,andminormodification.

2‐ Transformer Output.The Transformer used in the Sega G80 games employed several

moveableinputstoaddressavarietyofdifferentvoltagesinforeigncountries.TheU.S.

winding was rated for 110 VAC.Although it is commonly held that 110 VAC is the US

standardforvoltagethatisnotthecase.Usingamulti‐meterandmeasuringvoltageat

theoutletwillyielda

voltagecloserto120VAC(andsometimeshigher).Thismeansthe

outputofthetransformerispushingoutvoltagearound10%higherthanthegamewas

designed to take.Although the power to the game boards is regulated, the power

supplyisworkingharderthanitshouldandthemonitor getsthehighervoltagedirectly.

Simply modifying the inputs on the Transformer to a winding equal to 120 VAC will

correctthiscondition.

3‐ PowerSupply.TheG80powersupplyusesaTIP141transistoraspartofthe+5power

circuit.When this transistor fails, it can (and will) spike  the power in the  +5 line

supplyingthecircuitboards.Thisresultsinblownmemoryandsometimesworse.Itis

fairly easy to add a switching power supply to the +5 circuit that does not exhibit this 

behavior.Whenaswitcherdies,itdoesn’tspikethecircuitboards.Youjustreplacethe

switcher(cheapandeasy)andyouarebackinbusiness.

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Indice de contenidos

Pagina 1 - (ElectrohomeG08803)

Mongo’s*SimpleSegaG80VectorMods(ElectrohomeG08803)*actuallystolenfromvariousotherauthors

Pagina 2

Once it is all clean we  are ready to reassemble.Inspect the sockets for loose wires and thetransistors legs for corrosion.Any

Pagina 3

Justsmearathinlayeronthere

Pagina 4

Alsomakenotethattheholesfortheterminalsonthetransistorsareoff‐centerasaretheholesintheinsulators.Theyonlygoinoneway.You

Pagina 5

If your socket is sitting FLAT against the heat sink then you have things lined up right.Justscrewthetransistordown.Don’tapp

Pagina 6

NowthatIknowmymeterisworking,Ijustneedtoverifythetransistorsarenotshortedtotheheatsinks.JustmakingsureIhaveagoo

Pagina 7

I have put it back together after wiping  up the excess heat sink compound that I sloppedaround as it will attract dust.I

Pagina 8

There is a small “stop” punched into the monitor frame that helps you align the unit.It isalmostdeadcenterinthepicturebelow

Pagina 9

Ifyouhaven’tskippedaheadyounowneedtoreplacethethreeharnesses.The harnesses are keyed and only go on the connector one way

Pagina 10

You are now all done!Replace  themonitor, the four bolts, the power and inputharness andyou are ready to test.If you start

Pagina 11

…andtheACinputconnectorfromthepowersupply.Pertheschematics,themonitorisdesignedtotake45VACinputfromthetworedwires

Pagina 12

DeflectionTransistorMaintenanceandModificationSoherewego…Wewillstartwiththetransistormod.

Pagina 13

Asyoucansee,myvoltageis10%abovewhatitshouldbe.Thisisduetothetransformerbeingstrappedfor110Voltsbutgetting120Voltsfrommy

Pagina 14

Tomodifywhatvoltagethegameisstrappedfor,justlocatetheinputsideofthetransformer.Itshouldlooklikethepicturebelow(ifitdoesnot

Pagina 15

Plugthegamebackin(leavingthemonitorpowerunpluggedaswellasthepowersupply)andmeasurethevoltageagain.Thisshouldputyourightback

Pagina 16

SwitchingPowerSupplyModificationThismodificationisthemostdifficultofthethreeandwillrequiresomeelectricalknowledge*.Ihavechosen

Pagina 17

SinceIamgoodthere,Ineedtomakesureeverythinghasagoodearthground.Everypieceofhardwareinthegameshouldreadcontinuityontheme

Pagina 18 - TransformerModification

Nowtobuildtheadaptor.TheDCoutputonthep

Pagina 19

Nowyouneedtoattachyournewwirestothepowersupply.Makecertainthatyouputthe+5lineonthe+5lineontheswitcher,andyourgroundwire

Pagina 20

Makesurethateverythingisasitshouldbe(noshortedwires,everythingsecure),doublecheckmyconnections,andpoweritup!Youshouldimmediat

Pagina 21

Thepowerwirehasclipsthatneedtobesqueezedtogether.Theinputwireson

Pagina 22

First,youmaywanttoremovethewireharnesses(ther

Pagina 23

Inordertopullthesetwoharnesses,itmaybenecessarytoholddownthepaddleboards*ortheywillcomeloose.Notabigdealifthathappensbut

Pagina 24

Asyoucansee,gettingtothebottomoftheseheaderswillrequireremovaloftheentiremainboard.Whilethere,reflowingsolderonALLjointson

Pagina 25

Nowpullthefanbyremovingthefour 

Pagina 26

Youwillnoticeacrustywhitefilm(driedout

Pagina 27

Oncedisassembled,itistimeforsomecleaning.Whenclean,themicainsulatorswillusuallybeclear(ifyoudon’thavethetintedversionandaren