CorComp 9900 FDC PALs

[justacruzr2]

I have just finished replacing everything on my 2 CC9900 cards except the PALs and they still overheat and shut down within about 1-2 minutes. But they do work before they shut down. So it would seem that the PALs are bad. I have just purchased a lot of 10 12L6CN PALs but now need either what was burned on them or someone who has a good set to temporarily donate them for copying. They would be returned to you unharmed. I realize that trust doesn't come easy. This is a mission of mercy for the TI community. Several of us have CC9900 cards that need these to put these cards back to use. I have tried to find a way to contact both W R Moseid and Craig Miller but no luck. I will make the extra sets available at a very reasonable price. Would appreciate hearing from anyone who can help. Thanks.

[+Schmitzi]

Hi,

 

what is a PAL and what eqiupment is needed to read it out ?

 

xXx

[Omega-TI]

Hi,

 

what is a PAL and what eqiupment is needed to read it out ?

 

xXx

 

PAL stands for Programmable Array Logic

The kind he references can be seen << HERE >>

If working properly, at first I'm amazed they are 'overheating' without an external cause like a supply voltage issue, but then again I know just enough to be dangerous.

 

If it's not a supply issue, do you think the problem could be mitigated with heat sinks and some compound?

 

[atrax27407]

If the PAL hasn't been locked, a MiniPro Eprommer should be able to read it.

[+Schmitzi]

ah OK, thx

 

so, this is NOT the Bios/Eprom, right ? And let me guess, they are not socketed ?

[justacruzr2]

 

PAL stands for Programmable Array Logic

The kind he references can be seen << HERE >>

If working properly, at first I'm amazed they are 'overheating' without an external cause like a supply voltage issue, but then again I know just enough to be dangerous.

 

If it's not a supply issue, do you think the problem could be mitigated with heat sinks and some compound?

 

 

It's not the PALs that are overheating...it's the voltage regulators. Both of my CC9900s (1st release and Rev A) do the same thing. Every electronic component on both cards has been replaced, including the voltage regulators, except for the PALs. I have tried both cards in different slots but it makes no difference. All the other cards in my box work fine and their voltage regulators do not overheat so I don't believe this is an issue with the P-BOX power supply.. By overheat I mean like touching the burner on your stove right after you've cooked something.. They will normally be warm to the touch but not red hot. This happens about 1 to 2 minutes after powering up. My best guess is the PALs have something to do with steering current or voltage and maybe they are scrambled or erased internally causing the voltage regulator to get way too hot. My Rev A card I know took a static spike. The 1st edition card I don't know the history on but suspect something similar happened to it. A static spike can carry large voltage....enough to scramble or erase whatever was on those PALs. Since a PAL is an electrically erasable type of PROM (EEPROM) a static charge could easily erase or scramble its contents

 

@ atrax27407

As per above explanation, I believe mine no longer contain anything useful. They have probably either been erased or scrambled.

 

@ schmitzi

CorComp did socket the PALs on these cards which makes changing them a breeze.

 

Further Update:

I had the idea today that maybe not both PALs on both cards were bad so I tried swapping them individually one at a time only to find out that the 1st edition card PALs and the REV A card PALs are not compatible. By that I mean what is programmed onto them is different between the 2 versions of the card. Physically though, they are both 12L6CNs. Following the traces on both boards I was able to see that they connect differently and is probably why what is programmed onto them is different. The programming causes the pins of the chips to react differently. So now we would need a good set from both types of cards. Actually, the programming is probably the same but in a different order. Guess my best option is to go to one of the CTIUG meetings and see if someone has a working CC9900 they wouldn't mind lending for this purpose.

 

Edited June 16, 2016 by justacruzr2