TECH: Midway MCR power (Tron)

[Tom]

I have a Tron upright I just picked up. I have a working boardset and what
I thought was working power board for the cab.

I am getting 12v from the powerboard, however, I only get 2.79v on the +5
leads. The POT on the powerboard for 5v doesnt move the voltage at all.

My question is, for testing purposes, can I remove the four +5v pins from
the molex on the power board and run +5v from a switching PS without
damaging anything? Do I need to pull the ground from the MCR powerboard and
run it from the SW power supply as well?

My plan is to pick up the switching PS kit from Arcadeshop. A bit low on
mad money at the moment though.

Thanks!
-Tom

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[cnlmoore]

You may need to pick up the MCR switching kit from

http://www.wizzesworkshop.com/cart/default.asp

--
Chris M
Chicago, IL

Remove the OBVIOUS to reply direct
or cnlmoore AT hotmail DOT com

Looking for:
Leg levelers/ feet - the round barrel type from Tapper CT (possibly others)
Reactor parts
Coin box for Ms Pac CT

"Tom" <tombo...@SPAMhotmail.com> wrote in message
news:Xns954774325A901to...@129.250.168.17...

[Tom]

"cnlmoore" <cnlm...@OBVIOUShotmail.com> wrote in news:V27Uc.27670$Jp6.4516
@newsread3.news.atl.earthlink.net:

> You may need to pick up the MCR switching kit from
>
> http://www.wizzesworkshop.com/cart/default.asp
>
> --
> Chris M
> Chicago, IL
>

Yeah, thats the same(ish) product from arcade shop. A bit cheaper too!

I was just curious, in the mean time, can I run _only_ the +5v from a
switcher to power the game boards.

-Tom

_______________________________________________________________________________

[Zinfer]

If I recall correctly, there was a screw on all 4 corners of the main
pcboard stack that is used to interconnect the boards with standoffs
in between. This screw was grounding out on the pcboard. I found
that it was very hot to the touch. When removed the game came up,
voltages were great and it's worked fine ever since.
Just a reminder that there is a +12v adjustment pot and a +5v
adjustment pot on the power board.
You may have been adjusting the 12v on the power board and checking
the 5v cap on the main pcboard stack. Adjust your voltages first with
the main pcb stack disconnected. you can check your outbound voltages
first on the main power board with a multimeter on a couple of caps.
I believe those were C101 and C105. C105 was the 12v while C101 was
5v. I believe the proper setting was around 5.25 and 12.25v as there
is some voltage dropoff/loss through the harness to the main pcb
stack.
But your 2.79v that your currently getting sounds exactly like the
problem I was having before I found that damned screw.

Good Luck,
Rod

Rod's Arcade Restoration
http://www.kineplex.com

[Tom Bombaci]

rmas...@hotmail.com (Zinfer) wrote in
news:41210c2f...@news-server.woh.rr.com:

> If I recall correctly, there was a screw on all 4 corners of the main
> pcboard stack that is used to interconnect the boards with standoffs
> in between. This screw was grounding out on the pcboard. I found
> that it was very hot to the touch. When removed the game came up,
> voltages were great and it's worked fine ever since.
> Just a reminder that there is a +12v adjustment pot and a +5v
> adjustment pot on the power board.
> You may have been adjusting the 12v on the power board and checking
> the 5v cap on the main pcboard stack. Adjust your voltages first with
> the main pcb stack disconnected. you can check your outbound voltages
> first on the main power board with a multimeter on a couple of caps.
> I believe those were C101 and C105. C105 was the 12v while C101 was
> 5v. I believe the proper setting was around 5.25 and 12.25v as there
> is some voltage dropoff/loss through the harness to the main pcb
> stack.
> But your 2.79v that your currently getting sounds exactly like the
> problem I was having before I found that damned screw.
>
> Good Luck,
> Rod

Rod,

Thanks for the tip.

I am testing the power with the harness off the PCB. I made sure I was
twisting the 5v POT (checked twice) on the power board. The 12v POT works
flawlessly.

I used Bob's rebuild kit on the power board a few months back. Should
have just picked up the switching PS kit....

[Zinfer]

I was on the verge of doing that myself but then everything started
clicking in place here with the PS and the board repair. Richard
Cross did me a fantastic job on Tron. Fixed my Tron PCB and replaced
my PS.

On 16 Aug 2004 20:32:08 GMT, Tom Bombaci <tombo...@hotmail.com>
wrote:

Rod's Arcade Restoration
http://www.kineplex.com

[Matt]

To use a switcher for +5 only you will also need to attach a few of the ground
leads to the switcher from the linear supply. LEAVE the connections to the
linear intact and just add jumpers from the old supply's ground straps to the
switchers ground terminals. You can also strip back a bit of the jacket on a
few of the ground wires and solder jumpers to them. Whichever works best for
you in the long run.

Be sure to remove EVERY +5 wire from your old supply or that switcher will fry
more of the linear supply.

Matt

game...@aol.com

M and M Electronics
6661 Stanford Ranch Road
Suite F, PMB 105
Rocklin Ca 95677
916-275-5871