Evel Knievel SS playfield shuts down during gameplay

Todd

Now is a good time to expand your knowledge base of electronics. I suspect your 5 volts is dropping, which is causing the MPU to freeze.

Get a cheap multimeter, look at Utube to use the meter, then look at Pinwiki on how to troubleshoot the issue. You will need a schematic, which is available on IPDB.org

Post a few pics of the circuit boards in the head, especially the regulator board(lower right hand side with all the fuses), the MPU, (left side), and the SDB (solenoid driver board)on the right side.

Welcome!

#3 4 years ago

BTF

PinballManiac40

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14y 234K 17,622 104

Reseat the top left 2 connectors on the MPU board (top left) and the top right 2 connectors on the solenoid driver board (top right board).

If this helps, it will only be a temporary fix.

#4 4 years ago

???

Burtuckyboy

Inactive member

Thanks I appreciate the info. Will give it a shot later this evening. Have a great day!

#5 4 years ago

Madmax541

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11y 110K 2,059

Take picture of MPU and voltage rectifier board and post

#6 4 years ago

BTF

PinballManiac40

Pinside+ Frequent

14y 234K 17,622 104

Quoted from Madmax541:
Take picture of MPU and voltage rectifier board and post

This will help show if your game has been "bulletproofed" to make it working close to new or not. Original capacitors and connectors are high point failures in these older machines.

Congrats on your first game.

#7 4 years ago

AMR

BigAl56

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Palatine, IL

7y 64,800 1,655

Nice first game. Lets see photos of the circuit boards. Essentially interested if the original battery is still mounted on the MPU. At minimum you will need to be able to resolder the connectors on the board.

Think of your project as a 64 Mustang barn find. It sort of runs but were going to help you fix it up.

#8 4 years ago

???

Burtuckyboy

Inactive member

Hey friends, used my Gramp's old Sears voltage tester to see 5v at all Roms, but only 4v at Rom above LED A4 and one above it is 4.5v.
Also, did reseat top 2 left connectors on MPU and top 2 right on solenoid board. No go.
Trying to upload pics now. Also, i have the original schematics and manual. Thanks for any info on whats next!

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#9 4 years ago

???

Burtuckyboy

Inactive member

This the beast before it crapped out. Please let me know if any additional pics are needed. Pulled top off last week and noticed a regulator or something on left hand side near front of cabinet. Appeared to have had a metldown.

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#10 4 years ago

???

Burtuckyboy

Inactive member

Should I replace the MPU board???

#11 4 years ago

WFC

Billc479

Pinside+ Frequent

Replace the thermistor first. Look on the wiring schematic for the part number.

The thermistor is what burned up on the side of the cabinet.

#12 4 years ago

???

Burtuckyboy

Inactive member

https://www.marcospecialties.com/pinball-parts/CKBLY

Will do. Thanks for heads-up. Be safe and have a great evening!

#13 4 years ago

DAD

seeburg220

Inactive member

12y 58,300 540

Visually speaking, it looks like the MPU has battery corrosion on the board. That appears to be an original 43 year old battery. I would put it on my list to replace the battery or the MPU. Also, the rectifier and transformer look like they have been hacked. It should be mounted on the side of the inside of the cabinet, as shown below (IPDB photo). The connectors on it definitely look like they're in need of replacing. By now, most of them are in need of replacement. Marco has a kit, if you're into soldering. You'll also need a crimping tool.

https://www.amazon.com/gp/product/B007JLN93S/ref=ppx_yo_dt_b_search_asin_title

image-33 (resized).jpg

#14 4 years ago

BTF

PinballManiac40

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14y 234K 17,622 104

5101 NVRAM is plug and play in EK and gets rid of that battery.
https://www.pinitech.com/products/5101_nvram.php

#15 4 years ago

WTF

timab2000

Pinside member

6y 78,300 2,229

Before I'd do anything...I would sort out that recifier board.

That thing is a hacked up mess.

#16 4 years ago

GFO

Timerider

Pinside+ Pro!

Trevor, WI

11y 79,550 875 31

Fuse on Solenoid Driver Board appears to be jumped with a wire!

nofuse (resized).png

#17 4 years ago

AMR

BigAl56

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Palatine, IL

7y 64,800 1,655

First of all, as a former engineer I would absolutely love a project game like this!
You have all the symptoms of a classic Bally in need of an electrical overhaul. I recommend the following on the to do list...

* Rebuild the Power supply board. It needs new filter caps, and you should order replacement fuses for that board. the HV fuse hack is dangerous.
* Rebuild the rectifier board by the transformer. The existing is badly hacked up.
* As for the MPU, very likely the battery has leaked and damaged the board. At minimum you need to remove the battery and replace with an NVRAM chip. However, given the age, I recommend a new Alltech or Weebly replacement MPU.

I would start with the power supply. Recap the filter caps and replace the fuse with an actual fuse. That fuse is an odd duck size but you can buy replacements. They are available. Check the HV and try to adjust it to around 185v or so. Resolder the connector pins and the flipper relay connections.
From there replace the rectifier board with a new style and rebuild the connectors.
Along the way make sure the game boots and the voltages are correct. When you finish rebuilding the PS and Rectifier and the game still boots then rebuild or replace the MPU.

#18 4 years ago

WFC

Billc479

Pinside+ Frequent

Al
How do you feel about the bulletproofing of the Boards? I noticed you did not mention anything about doing that.

#19 4 years ago

AMR

BigAl56

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Palatine, IL

7y 64,800 1,655

I've seen the posts about modding Bally boards to be 'bulletproof'. I'm reluctant to do so only because it does involve hacking up the boards and opens up the possibility of introducing another fault. There are thousands of unmodified board sets out there working fine with a few minor updates. If you do want to perform the mods I would recommend sending the boards out to a pro unless you are very confident on your tech and board soldering abilities.

#20 4 years ago

237

slochar

Pinside member

7y 86,550 6,884

The only bulletproofing I like is the mod to not use the connector pins to carry the +5v from one section of the SDB to the other. The other common ones I'm on the fence about, I may or may not do them. (Beyond the replacing of capacitors).

#21 4 years ago

???

Burtuckyboy

Inactive member

Thanks everyone for the info! Really appreciate it. I'm only into this pin for $1200. So I don't have a problem putting some money into it to make it tip top since its a keeper. Feel more comfortable taking it to someone who repairs these when things get back to normal in TN. Rather pay to have it repaired correctly, than mess it up myself. Maybe someone on this forum know's where to take it in Nashville area?? I'm in Columbia (30 miles south of Nashville) and it does not appear that anyone here local repairs these. Thanks again everybody for your time. Be safe out there!!!

#22 4 years ago

WFC

Billc479

Pinside+ Frequent