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Title: Perplexing problem with Bally 5500 slot Post by: ucanwin on February 11, 2013, 11:14:52 PM Problem on a Bally 5500 slot......
I had problems with 2 Lithium 3.6 V batteries going dead in a short period of time. So, I decided to use StratFreaks idea with using 3 AA Alkaline batteries and an IN4004 diode mounted on the outside of the board. I did a ram clear, and the machine operated just fine. I could turn the game on and off in a short period of time and everything was great. But, after the game stands for several hours, it comes up with an 83 safe ram error. I can do a ram clear, and it's OK again.....as long as the machine is not turned off for several hours or more. Any Idea why this happens? Is there anything I can do to solve my problem? Jerry Title: Re: Perplexing problem with Bally 5500 slot Post by: rslots on February 12, 2013, 02:07:58 AM Did you check voltage again on your triple battery set to see if they had rally discharged that quickly? Sounds like you have had issues with batteries going dead quickly, so the root cause still has not been addressed (i.e. what is causing such a quick drainage?) I have had a few boards that either drained the battery very quickly or else always showed a dead battery (even with a new battery). I replaced the boards in both cases to solve the problem. Otherwise, need to find someone who can fix your board if indeed it is quickly drawing down the battery.
Title: Re: Perplexing problem with Bally 5500 slot Post by: ucanwin on February 12, 2013, 02:34:42 AM I just checked the battery voltage with the machine turned off. It is 3.91 V.
Title: Re: Perplexing problem with Bally 5500 slot Post by: rslots on February 12, 2013, 03:02:21 AM So looks like you have the 2nd problem I spoke of which is a false "dead battery" indication. I never figured what was causing it (actually never tried to) and probably still have a couple boards in the pile with that problem. May want to get another MPU board.
Title: Re: Perplexing problem with Bally 5500 slot Post by: Mr. Dinoman on February 12, 2013, 04:29:02 PM Do you have jumper 12 installed?...Check voltage at TP10 on the MPU board...
Title: Re: Perplexing problem with Bally 5500 slot Post by: ucanwin on February 12, 2013, 05:07:51 PM Jumper on J12 is on. TP10 checks 3.91 V
Title: Re: Perplexing problem with Bally 5500 slot Post by: Mr. Dinoman on February 12, 2013, 06:15:21 PM It sounds like the battery memory circuit is failing...Attached is a schematic of it...
Title: Re: Perplexing problem with Bally 5500 slot Post by: MarkInAz on February 26, 2013, 04:55:30 AM Yup, I agree Dinoman. Might try watching the 2.5VDC reference signal at power up and see if it spikes causing the false VDD_BAD signal. I might just shotgun it and replace all those big old electrolytic capacitors, especially C-5 at the Ref chip.
Mark |