I will. No worries on anything. The order is fine. This is not the only issue I am in the process of working with this 6803, I've also got an XPIN display issue, ongoing in another thread

I spent all last summer and half of fall on FBII, with the playfield swap and everything that followed. It's my contention that the other two pins are just getting jealous

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The D&D pin just needs a bit of love, which it has been getting since Thanksgiving. Most of it I've done myself, with a lot of source material and advice from Pinside and other sites to guide me. I appreciate the help, more than I can express. I hope to pay it forward, in a good and responsible manner, some day for somebody else that wants to jump right in LOL.

The first thing I ever really did with a pinball machine, wasn't playing it, it was that PF swap. I had no idea what I was doing, but I knew what it was going to be like.

Or so I thought

That is kind of backwards in the learning curve, but I am pleased that it has all went as well as it did. Information and help are critical, especially on these older games.

I found that with my Bally games I can get at least 3 months memory retention. I think the long memory retention is due to using a PCD5101 at U8.

I read that the PCD5101 were the last 5101s that were manufactured & they were the most economical with current draw, quite a lot less than any other 5101s, so this makes them the best 5101s to use in this application. (Ed from GPE had mentioned this somewhere).

I found on a Williams system 6 game that I needed to install 2 x 1.5 farad caps in parallel to get decent retention as the Williams games seem to consume more current than the Bally games. The blocking diode is bypassed to allow current to flow to the caps. A resistor is also installed to slow the capacitor's charging rate. I think I get 2 months retention or so, which is great. The Bally games only needed a single 1.5 farad.

Personally I much prefer a memory capacitor to a coin battery for backup. (my Firepower had been already converted to a coin battery backup as can be seen with the holder) If a blocking diode fails & a coin battery receives a charge it can explode (apparently).
So, essentially I guess you would be relying on a blocking diode alone not to fail.

Setup on my Firepower. Note a PCD5101 RAM is installed.
IMG_9855 (resized).JPGIMG_9856 (resized).JPG

If you're not playing your games in 2 months, you're not doing it right.

Yes, good point, I agree!, but in this case the 2 months I was referring to was when I was away for that entire time & they wern't switched on at all, so this was a good time to test if the memory backup held up.

I also had a spare Bally mpu (out of the game) with a charged up memory cap, I tried that back in a game after about 3 months & the bookkeeping was fully retained.

Usually about 1 week max without having a game!!

Each battery measured 1.6V, and I got 5.4VDC from the ground point on the MPU to the diode in the battery pack.

Wait a minute. 5.4VDC is what you get with the game on. I know this because 3x1.6 does not result in 5.4VDC. what do you get at the same point with the game off?

Screenshot_20190130-172203~01 (resized).png

In fact, take two measurements....from ground to diode anode and ground to diode cathode with game off.
The diode anode should measure about 4.2VDC game off or on.
The diode cathode should measure about 3.5VDC game off, and measure 5.4VDC with the game on - this is the charging voltage that is blocked by the diode so that the game doesn't attempt to charge your batteries.

Took both measurements

Game on

Ground to cathode - 5.4V
Ground to anode - 1.9V

Game off

Ground to cathode - 3.4V and it drops fast
Ground to anode - 1.1V and it drops fast

Measured R28 - read 271

Something is not good here, and it looks like the diode is a part of this problem, but your pack also appears to be incorrectly wired. The diode should be a standard 1N400X (4001,4002, etc) silicon diode. The battery voltage should not change at the anode regardless of the game on or off, and the 3 batteries each measuring 1.6VDC should total about 4.8 VDC. When the game is on, you will see the games power (VCC) of 5.4VDC at the diode cathode. This should be completely blocked by the diode and have absolutely no effect on the anode side - which should total all three batteries as said before. When the game is shut off, you should still see the battery total voltage at the anode, but instead of VCC at the diodes cathode, you should see the battery voltage minus the diodes 0.7VDC drop - about 4.1 VDC.

Disconnect your pack, check wiring and diode, and confirm you get the measurements as shown in the game off diagram below.

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Ok, put in a spare battery pack. It's only a two slot pack, so only one battery. It measured 5.4V on cathode end with the game on, and 1.3V with the game off.

In the four slot pack I used a 5817 diode, in the two slot pack I used a 4007. I turned it off while cleaning up, approximately 3-4 minutes and all settings were saved when I powered it back up. I'll turn it off tonight and see what the morning brings.

The four slot pack was wired correctly, so I guess that leaves the diode as the culprit

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measured anode end, 1.6 volts with the game on and off. And it didn't drop with the game off.

Yes, diode bad or leaky.

Are you sure you're installing the 3 batteries the right way around? You might have one installed backwards which is effectively cancelling two batteries out. Can you post a picture of this 4 slot battery holder?

wayout440 you might want to correct your battery diagrams, you have two positives connected together

1N5817 are commonly used as a battery blocking diode because they have lower voltage drop compared to a 1N4007.

Whoops. Thanks quench.

I have it out and packed away, so I can't provide a picture, but the batteries were installed properly. I pulled them all out and re-seated different batteries in different slots. I did that several times.

After my post last night, I turned the game off at 2100, powered it back on at 2215 or so. All settings with the 2 slot pack installed, were saved. Left it on til around midnight and didn't turn it on until this morning at 0930. All settings were saved.

The NVRAM arrived this morning. I disconnected the battery pack from the board, installed the NVRAM, factory reset the machine and set it up again. All settings saved and good to go.

I am suspecting the diode, or some damage to the wiring when I soldered it. Here is something for consideration. When I un-installed the four slot battery pack, the wires (by my choice) were soldered to the back of the board. The 2 slot pack, I left the board installed and soldered the wires to the front of the board. It was a sloppy job because I knew the NVRAM was in the mail, and that it was only going to be temporary but it worked for the test.

Don't know why (not the sloppy part ) that configuration would have made a difference, but that is the only difference in how the packs were attached to the board, other than the number of batteries.

I copied the configuration from the 6803 repair site, for my four pack. That picture was posted somewhere earlier in this thread. That is, essentially, a picture of my setup.

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btw, I'm getting a bit long-winded here but a little story that emphasizes how I tend to go about things that I have working knowledge of - always look for the simplest thing first. I have a cartoon around here on paper, from back in the 90's, that is a funny mock-up of an S3-B simulator environment. I developed courseware for the S3-B, that emulated the simulator that the pilots trained on. Anyway, it's a total mock-up, two techs (one scratching their head, the other shrugging) because they can't figure out why the damn thing won't work. And off in the corner, out of site, is a power cord laying on the floor unplugged

LOLOL

Some people get offended by those types of questions. I learned a long time ago, if you're going to be stupid and miss the obvious, make sure there are no witnesses and learn it going forward

If you are in a band and make a mistake, give a weird look to the guy playing next to you.

lmao, indeed.

Now, I have a few connectors on the MPU board I want to upgrade, then it's on to figuring out what's up with my XPIN display issue. The plasma's are working fine, btw. But I know a day will come when they will give up the ghost.

Thanks all for the help. And thanks to Pinitech for a great product, and excellent turnaround on my order