Author Topic: Wpc 89 board Display Corruption..  (Read 885 times)

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Offline TUF-427

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Re: Wpc 89 board Display Corruption..
« Reply #30 on: March 27, 2014, 10:35:44 PM »
Update socketed and replaced the 6264 chip and installed into the shed pin BSD.

straight to display test ran perfectly for 3 full test sequences..had a game seemed fine..

left machine on for awhile started to notice some artefacts on the Dmd again..

Ran display test arain same old Ram address error..

soooo looks like something gets warm after Machine being on for awhile... ^.^
Firepower, F14 Tomcat, Terminator2, Twilight Zone, No Fear, TAF, Hyperball, Sttng....

Offline Marty Machine

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Re: Wpc 89 board Display Corruption..
« Reply #31 on: March 27, 2014, 10:42:30 PM »
Sheesh, this seems to be getting nastier each time :-(

Assuming the 6264 is new and/or proven on other machine(s) ????

You may wanna check/replace the bypass capacitor associated with the 6264 and any other bypass caps (especially tantalum types) around other memory chips.
'ghosty data' is usually corrupted ram data when bypass caps go open (or short) and alter the digital 5v signals to 2.5volts into the 'no go zone....

fingers crossed...

Offline TUF-427

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Re: Wpc 89 board Display Corruption..
« Reply #32 on: March 27, 2014, 11:31:54 PM »
Sheesh, this seems to be getting nastier each time :-(

Assuming the 6264 is new and/or proven on other machine(s) ????

You may wanna check/replace the bypass capacitor associated with the 6264 and any other bypass caps (especially tantalum types) around other memory chips.
'ghosty data' is usually corrupted ram data when bypass caps go open (or short) and alter the digital 5v signals to 2.5volts into the 'no go zone....

fingers crossed...

Cheers for the tips Marty yea brand new 6264 chip a little faster than the original but should be good..

I will have a new board by the time Ive finished!
Firepower, F14 Tomcat, Terminator2, Twilight Zone, No Fear, TAF, Hyperball, Sttng....

Offline Marty Machine

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Re: Wpc 89 board Display Corruption..
« Reply #33 on: March 28, 2014, 04:57:02 PM »
Cheers for the tips Marty yea brand new 6264 chip a little faster than the original but should be good..
I will have a new board by the time Ive finished!
....or no hair left to pull out  ;-)