Jump to content
Due to a large amount of spamers, accounts will now have to be approved by the Admins so please be patient. ×
IGNORED

Mirco 'Challenge' 4 Player Pong - PCB Repair Log #1


Recommended Posts

I've had this cab for a couple of years now, I won it on an Ebay auction and had it shipped up from Melbourne.

 

http://www.arcade-museum.com/C/Challenge.html

 

 

Video of the game play.

 

 

rtw4Drt.jpg

 

c5eevl4.jpg

 

 

It was working when I got it but it's been stored away since then, waiting for a cosmetic restoration. @zanderzone also has one with a faulty PCB which he dropped off for me to have a look at for him.

I dusted the cobwebs off and powered it up to check both boards.

 

My board has issues with the paddles, the right side has them doubled up and the ball is missing when you try to start a game.

 

7kIwL4X.jpg

 

Zanderzone's board was totally dead.

The crystal was working but the 7404 directly below it was faulty, I replaced it but there are further issues.

A quick check of the voltage (+5v only on these boards) and it was sitting at 6.38 vDC. One of the four 5k pots had corrosion on the connector and they were all a bit scratchy.

Rather than working on top of the cab, I decided to get it onto the test bench.

I have a 3.5" reversing camera monitor with AV (composite) input and runs off 12 volts the board on required 5v so it used a PC power supply to run both.

 

Four new 5k pots and a couple of switches completed the setup but I didn't have any of the connectors that plug onto the board so I soldered all the connections for the controls to the underside of the board. Power and video were connected via modified crimp connectors so I could still swap between boards.

 

6vzINfP.jpg

 

I've started to write up a pinout, theres no schematics in the manual that came with it which I've scanned and uploaded to KLOV.

 

W9Phi4e.jpg

Edited by Kaizen
  • Like 1
Link to comment
Share on other sites

I've made a little bit of progress on my PCB this morning, I found two 7400's with stuck outputs (2A &2F).

I socketed and replaced the IC's at both location with no visible change. I also cleaned up a some previous repairs at 3C.

After a bit more probing I found another 7400 at 5E with a stuck output, replacing that has brought the ball back in to play.

 

 

The ball won't rebound off the bats or lower border so there's still plenty of work to do...

Scoring is working fine, there's still the issue of the bats on the right side being doubled up.

 

The pinout has been cleaned up and uploaded to KLOV.

 

6VMN9mq.jpg

Edited by Kaizen
  • Like 1
Link to comment
Share on other sites

  • 4 weeks later...

I spent a bit of time on my PCB and cab today and finally got it sorted.

 

One of the bats was stuck at the top and would only move a fraction downwards, I traced it back to a bad 100nF ceramic cap, I swapped it out and the problem was sorted. I also changed the one across the other three pots for good measure.

 

The next issue was the the bottom line was missing and the ball would pass from the bottom of the screen and reappear at the top only moving in the downward direction as there was no hit detection. I found a faulty 7427 and replacing that got it back again.

 

While testing on the bench I noticed that when first powering the PCB up it would have issues trying to sync and the LCD would flash on and off a few times before becoming stable, this increased more and more until I lost the clock altogether. Starting at the crystal I could see there was no activity on one of the gates of the 7404 that forms part of the clock circuit, replacing that got the image back and it was syncing straight away again.

 

The last issue was that the ball speed was stuck at full speed, there's a 7493 that controls the ball speed and one of the outputs was stuck low. After close inspection of the underside of the board with +4 glasses I could see a tiny piec of wire forming a bridge. After removing that the board is now fully working.

 

I replaced the four 5K pots on the cabinet as well as the two LEDs for lighting the coin door and the free game LED. The switch for selecting the Player vs Game/Player had a broken lever so that was also replaced.

 

 

Job done and the cab is now fully working. :D

Edited by Kaizen
Link to comment
Share on other sites

When I started at Musictime in 1976 ?? 'ish - there were about 30 of these stacked above the toilet block in the factory at East Brisbane.

 

These are the reason the boss would never even consider buying ANY video game after this disaster and it took a LOT of convincing to encourage him to buy the first Space Invaders. :lol

Link to comment
Share on other sites

When I started at Musictime in 1976 ?? 'ish - there were about 30 of these stacked above the toilet block in the factory at East Brisbane.

 

These are the reason the boss would never even consider buying ANY video game after this disaster and it took a LOT of convincing to encourage him to buy the first Space Invaders. :lol

 

They weren't cheap as an investment either, here's a 1975 advertisement for my other 4 Player Pong Clone.

 

WPvHq0z.png

 

'The New Money Machine' :lol

Link to comment
Share on other sites

"out of town enquiries write to"

 

What does that mean? :lol

 

It's kind of like a TXT but you write the message on a bit of paper, pop it in an envelope and travel to the nearest post office then wait 3-4 days for it to arrive at the destination. After a day or two they'd respond and you'd get a message back in another 3 or 4 days.:laugh:

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...