4 replies to this topic

[studio251]

Hi,

I have had a 'Viva Las Vegas' Barcrest machine at home for the fun of it for about 10 years. About 6 years ago it was banished to my garage due to moving to a smaller house

It hadn't been used for probably 5 years until recently I plugged it in to show a friend. Immediately it scared the living s**t out of me - the payout solenoids buzzed and banged for a few seconds before finally settling down and completing the usual boot/test sequence. All then worked ok except the message display which was full of 'junk' characters!

This weekend I tried again and the noise to start with is horrendous but now the boot doesnt even complete. I thought about looking at the PSU because of the frequency of the solenoid clatter, looking for larger Capacitors to replace but first decided to have a 'Google' around and found several sires including this fun one (Im about to d/l and play with the emulator)

I read through some posts on these sites thinking I'd like to try a repair. Ive been in the office machine industry for some 23 years so these older electronics are relatively familiar.

I found the posts about the leaking battery and upon opening up the MPU4 main board assembly, sure enough the bugger has leaked all over. I removed the battery, cleaned the mess with standard PCB solutions and checked for broken tracks. Despite the obvious corrosion all appeared to have suvived so I reassembled expecting a good boot with a low/dead battery error.

Before starting up I deliberately left the Triac connnector off to avoid the noise.

The reels began to usual routine then they stuttered and within a few seconds smoke was pouring from the PCB (some of you must be laughing now!). Turns out one of the driver IC chips for the steppers has completely been destroyed and I really dont know why this should have happened.

So if any of you pro engineers can give some pointers please I'd be very grateful.

I obviously need a new PCB (ebay or are there other sites?) and maybe should go ahead with the Caps on the PSU, or should I just dump it and be done with it?

Its all for fun so I cant spend too much.... - but I'd like to try this...

Sorry for the long post, thanks to all that read,

Regards,
Mark

[cardie]

Hi,

I have had a 'Viva Las Vegas' Barcrest machine at home for the fun of it for about 10 years. About 6 years ago it was banished to my garage due to moving to a smaller house

It hadn't been used for probably 5 years until recently I plugged it in to show a friend. Immediately it scared the living s**t out of me - the payout solenoids buzzed and banged for a few seconds before finally settling down and completing the usual boot/test sequence. All then worked ok except the message display which was full of 'junk' characters!

This weekend I tried again and the noise to start with is horrendous but now the boot doesnt even complete. I thought about looking at the PSU because of the frequency of the solenoid clatter, looking for larger Capacitors to replace but first decided to have a 'Google' around and found several sires including this fun one (Im about to d/l and play with the emulator)

I read through some posts on these sites thinking I'd like to try a repair. Ive been in the office machine industry for some 23 years so these older electronics are relatively familiar.

I found the posts about the leaking battery and upon opening up the MPU4 main board assembly, sure enough the bugger has leaked all over. I removed the battery, cleaned the mess with standard PCB solutions and checked for broken tracks. Despite the obvious corrosion all appeared to have suvived so I reassembled expecting a good boot with a low/dead battery error.

Before starting up I deliberately left the Triac connnector off to avoid the noise.

The reels began to usual routine then they stuttered and within a few seconds smoke was pouring from the PCB (some of you must be laughing now!). Turns out one of the driver IC chips for the steppers has completely been destroyed and I really dont know why this should have happened.

So if any of you pro engineers can give some pointers please I'd be very grateful.

I obviously need a new PCB (ebay or are there other sites?) and maybe should go ahead with the Caps on the PSU, or should I just dump it and be done with it?

Its all for fun so I cant spend too much.... - but I'd like to try this...

Sorry for the long post, thanks to all that read,

Regards,
Mark

welcome to the site mark

no expert in mpu4 machines but if a chip has been destroyed some how i would recommend that you check to see if the battery has leaked onto the board as its common in all machines hope this helps to diagnose you problem

[stanmarsh14]

Would also help for waiting for some members like aaamusements to lend a hand in this, or try over at the mecca: The MPU Mecca

*** EDIT *** Just found a similar post to yours concerning battery damage and quite poss other MPU damage: http://www.fruitemu....read.php?t=3753 Looks as if aaamusements is about too.

[aaamusements]

Yep, massive battery damage by all accounts - the alkali gets inside chips and destroys them in some cases.
It should be fixable by someone on the Mecca as suggested above.

[studio251]

Hello all,

I've posted pictures if anyone here is interested, at the Mecca...

Looking for MPU4 Main Board - The MPU Mecca



Regards,
Mark