DDP: Doj owners: CHECK YOUR BOARDS!

[robivy64]

I just opened mine up for a dust check, and noticed that the battery was bloated and starting to leak acid. Fortunately it had not hit the board yet or there would be trouble. I removed the battery until I can get a replacement.

You guys need to open yours up and do a preventative maintenance inspection!

[fuko]

I replaced mine 2 weeks ago. The pads and adjacent traces had already started to corrode

[PC Engine Fan X!]

Is this regarding checking out the battery on such a regular "plain vanilla flavored" Cave DDP-DOJ PCB setup and not the DDP-DOJ "BL" PCB version?

Thanks for the handy tip...will check it out. The Cave seal on my DDP-DOJ PCB hasn't been broken yet. ^_~

And what is the purpose of this "back-up" battery on such a DDP-DOJ PCB for anyways?

The "back-up" battery on a Ketsui PCB isn't connected to anything at all...

PC Engine Fan X! ^_~

[Hewitson]

Surely they didn't put a battery on there for no reason

[robivy64]

The battery keeps the board settings live in the static RAM. Without the battery connected, it defaults to factory settings each time you power it on.

[dpful]

WTF? When I read this post, I didn't believe for a minute that mine would have a problem. I checked it and the battery is all corroded at one end.
What the hell is wrong with these boards? Is my esp galuda going to have the same problem?

I took the battery out. Is there a replacement that won't disintegrate, or is it just a badly designed board?

[it290]

It's just the battery style used (are they NiCads?); these things aren't really intended to last eternally in the first place. Tons of old Amigas have the same problem. It should be possible to mod the board and replace the battery with a battery of equivalent voltage (lithium, for example).

[Hewitson]

These types of batteries leak when left unused for long periods of time. These boards were designed to be in machines running 24/7 not sitting around in peoples homes.

I advise anyone who buys a board with a "barrel" type battery on it to replace it to avoid it leaking & damaging the board. Be warned that they are usually rechargable and if you put a non-rechargable in its place you will blow the battery & get acid all over your board.

[rtw]

That battery is also used on Espgaluda & Ketsui.

It's a NiMh battery. Details may be found here:

http://www.world-of-arcades.net/Cave/Dd ... rdware.htm

rtw

[oxtsu]

should be noted.. the 'powered on' thing only applies to DOJ Black Label. The others you can replace powered off as normal.

factory battery replacement available here.

[rtw]

Above is a the battery circuit used on CAVE PGM PCB's.

For DaiOuJou & DaiOuJou Black Label the resistor value is R6 but for Ketsui & Espgaluda it is R11.

Thanks to Kold666 & MKL we finally know the purpose of the SW1 switch
on the PGM PCB. It's purpose is to reset the NVRAM by forcing the VCC
pin on the NVRAM to ground!

This means that if you toggle the switch on a DaiOiJou Black Label you
will erase the magic id stored there and the board will show "ROM ERROR".
This might be the reason for the elaborate blue metal case and seal.

Kold666 & MKL have also devised a method of replacing the rechargable
3V6 NiMh battery with a normal non chargeable 3V6 Li-Ion battery by
disabling the charging circuitry.

There are two options:
. Remove diode D2, this will cause the battery to only power the NVRAM.
. Remove SMD resistor R6, this will allow the +5V to power the NVRAM when the PCB is powered, thereby increasing the length of the battery life. This mod is complicated because of the tiny SMD.

Note:
On a DaiOuJou Black Label both these battery changes have to be done while the PCB is powered on

rtw

[SePh1r0tH]

Sorry to bump an old thread. I am having a problem with my daioujou board recently. I opened the case and the battery is not leaking or anything. The screen is all distorted and just scrolls to the left upon booting. If I hold the switch next to the battery while it is booting, the screen stays still and shows some different colors. I am using the black label EPROM, tried reseating it.

Any ideas, should I remove the battery ?

Thanks

[_rm_]

Are you sure it's not just a simple sync problem?

Not saying it's your case, but i find incredible the amout of people that owns candy cabs and have no idea about H. and V./hold pots.

[trek5900]

Above is a the battery circuit used on CAVE PGM PCB's.

For DaiOuJou & DaiOuJou Black Label the resistor value is R6 but for Ketsui & Espgaluda it is R11.

Thanks to Kold666 & MKL we finally know the purpose of the SW1 switch
on the PGM PCB. It's purpose is to reset the NVRAM by forcing the VCC
pin on the NVRAM to ground!

This means that if you toggle the switch on a DaiOiJou Black Label you
will erase the magic id stored there and the board will show "ROM ERROR".
This might be the reason for the elaborate blue metal case and seal.

Kold666 & MKL have also devised a method of replacing the rechargable
3V6 NiMh battery with a normal non chargeable 3V6 Li-Ion battery by
disabling the charging circuitry.

There are two options:
. Remove diode D2, this will cause the battery to only power the NVRAM.
. Remove SMD resistor R6, this will allow the +5V to power the NVRAM when the PCB is powered, thereby increasing the length of the battery life. This mod is complicated because of the tiny SMD.

Note:
On a DaiOuJou Black Label both these battery changes have to be done while the PCB is powered on

rtw

Super old thread, sorry about this. The link to this image is dead, do you still have it?

[rtw]

Super old thread, sorry about this. The link to this image is dead, do you still have it?

Fixed