Hot DRAMs

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Mr.Fix's picture
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Hot DRAMs

Hey all, i have a apple 2+.  I am having an issue with the onboard DRAM on the motherboard.  I have noticed that all DRAM banks are heating up.  I have checked voltage at PSU, and they are within voltage spec (+-5,+-12).   I have tested the DRAMS with APEX diagnostic software and the results are the DRAMs are good (no bad chips). I have taken out all the DRAMs from the motherboard and filled up first bank, and this entire bank is heating up.  Any ideas on what to check?

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Have you used a thermal

Have you used a thermal reader to determine the actual temp? You can buy them inexpensively, around £10-20, at any hardware shoppe or automotive shoppe. It would help to know the actual temperature to know if they are actually overheating, as DRAM does tend to get warm. 

 

Further, what exp cards are you using, and what is the ambient temperature at which you are running the machine; and are the vents blocked by anything?

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TmeLord: yes, i have taken a

TmeLord: yes, i have taken a temp read on each DRAM and BANK.  all are consistant at 38c after 2 mins of bootup.  Only cards i have installed is the 16kb language card @ slot 0, booti card @ slot 5, and diskII controller @ slot 6, and VidHD @ slot 3.  I have also removed all cards except the language card and diskII card.

Ambient temperature is 21c, open lid.

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Are you sure with the

Are you sure with the measurement?

38°C is just above body temperature. That would feel a bit warm, like a mild fever, but not really hot.

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38 isn't that hot

Agreed - the DRAMs in my II+ clone get warm to the touch in about 5 minutes of on-time.

Lower 16K hits 30°C after just 5 min.  Middle and upper 16K banks get to about 27°C.  So mine are not much hotter than yours.

The video overlay chip on my Videx 80 col card is running at 50°C after 5 min.  I don't think this is out of the ordinary.

 

Perhaps you could desribe what the RAM issue is that you're experiencing.

 

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thanks all, if its normal for

thanks all, if its normal for the DRAMs on the ii to warm up during operation, than thats great, i just havent had the ii very long and i was concerned about the heat coming from the specific chips.

Currently no issues with the II, learning basic, and playing some adventure games on it. 

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Well, 16Kbit DRAMs were

Well, 16Kbit DRAMs were cutting-edge, mind-blowing technology in the 70s. :-) Except for the CPU, few of the other chips had so many gates squeezed into them. And all of its cells are constantly being refreshed, so they dissipate quite some power.

It's a good sign when they all have about the same temperature.

 

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