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Theatre of magic problem

  • Thread starter Thread starter Emlclcy
  • Start date Start date
E

Emlclcy

I've a theater of magic machine that has been in storage for about 15 years, when I power it up the cpu card flashes the centre led twice which the manual says is a RAM error U8, this part is soldered into the board so not a chip socket issue. Ive replaced the 3 batteries.
any ideas where to start?
thanks
carl
 
Where the batteries still in there from storage that you have replaced?


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Or the u8 chip could be bad. Would need to be desoldered, socketed, and new chip installed.
 
Chris said:
Where the batteries still in there from storage that you have replaced?


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Click to expand...
Yes they were, the batteries hadn't leaked but the terminals were a little green. The batteries are mounted on a separate board on standoffs on the cup card. The voltage at the cup end is 4.7v
 
took the cpu card to work and cleaned it with IPA. the top part of the board had shinny solder joints but the lower 1/3rd where the batteries are was grey an not to nice. I unplugged all the socketed chips, gave then a once over with ipa. but it still is the same. Ive ordered an identical sram but its coming from china so will take ages. anyone got one they could sell me?
cheers
carl
 
i was thinking about the memory being faulty, not sure how the battery connects to the sram but if it pulled down the supply to the chip whilst it was being accessed maybe that was enough to kill the chip. trouble is they are very difficult to source
 
btw this isn't the theatre of magic that was on ebay that had been in a barn or something a few weeks/months ago?
 
Sounds like mpu battery acid damage to me. Just replacing batteries doesn't remove the mess made by the previous batteries. Any chance of some close up photos of the mpu around where the batteries used to be?
 
Neil McRae said:
btw this isn't the theatre of magic that was on ebay that had been in a barn or something a few weeks/months ago?
Click to expand...
no, the ex landlord of a pub has 3 machines in a lockup he wants to sell and this was the first he tried powering up
 
Moonraker said:
Sounds like mpu battery acid damage to me. Just replacing batteries doesn't remove the mess made by the previous batteries. Any chance of some close up photos of the mpu around where the batteries used to be?
Click to expand...
well here is an update, I replaced the 8k SRAM and powered up, the error code led stayed off, drat!! so I unplugged everything except the power cable and switched on, the leds all did the right thing with the centre one flickering. so I pugged each cable in powering up until the ribbon cable that drives the display board caused the problem again. I removed the display board, looked for anything obvious, checked the fuses and put it back together. Bingo she powered up and I was then able to enter the diagnostic menu. none of the solenoids work and checking all the remaining fuses F105 the solenoid supply fuse is OC. so that's todays task, get a new fuse
 
latest update.
changing the SRAM seemed to fix the dead cpu as she powers up and goes into attract mode. The playfield light flash.
No power to the solenoids tho, running the diagnostics I can get 'most' of the switches to respond but no solenoids.
Display shows 'check fuses F114 & F115'

fuse and voltage status
power board
F101 should be 50VDC measures 103VDC
F102 should be 50VDC measures 103VDC
F103 measures 103VDC
F104 measures 103VDC
F105 measures 103VDC
F106 measures 0
F107 measures 0
F108 measures 0
F109 measures 0
F110 measures 0
F111 measures 0
F112 measures 55VDC
F113 measures 3.6VDC +5V logic
F114 measures 8V says 18V lamp matrix
F115 measures 12VDC 12V switch matrix
F116 measures 6.7VDC 12V secondary

Audio Board
F501 measures 0 says -25V
F502 measures 0 syas +25V

Dot matrix board
F601 measures 52V says 62V
F602 measures -65V says -113 and -125 circuits

fliptronic board
F901 measures 100VDC
F902 measures 100VDC
F903 measures 100VDC
F904 measures 100VDC

power board leds
all on except LED1 & LED5

CPU board
D21 on
D20 flashing
D19 off
machine in powered up attract mode status

any ideas where to look?

cheers
carl
 
o and the voice part of the diagnostics work so does the display test
 
Emlclcy said:
when I was noting down the voltages I measured either side. When I got the machine F105 was OC but now replaced
Click to expand...

You have to take the fuses out to test them.


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you know looking at a pinball with the table up, back light out, it makes you wonder how the shuttle ever worked
 
ive pulled each fuse and they are all good. anyone near Hampshire fancy having a look?
 
A lot of the fuses listed are AC voltages. So you’ll get meaningless readings on dc. Any input fuse like F101 to 105 will be AC. You need to measure those on a AC scale with one lead on each of the inputs NOT against ground. Same with the fuses in the bottom left which are GEneral Illumination.
 
Martin @gopinball is a pinball repair man = hes on holiday this week but back next week -worth him. coming down to have a look. He knows Theatre of Magic well - he did mine up :D

16422913_1203172973130798_8591167742047384590_o.jpg
 
I have the manual for this machine date march 1995. page 3-8 'low power solenoid circuit' shows a bridge rectifier BR3 connected to fuse F112 (AC side), fuse F104 DC side with a 100uF 50V cap. I unplug J107 & J102 and STILL measure 107V DC on F104 wrt the upper right corner of the power board J103 (GROUND)
don't get this, just doesn't stack up, the fuse F104 should have nothing with these two connectors removed
 
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