Decoupling capacitors

[orange]

arrrr... ALL TRACES ARE GOOD!!!
The voltage is a bit lower, about 4.78 V..

[minator]

Quote:

Jeff wrote:
Decoupling capacitors are indeed necessary . Watch the video of Jeri Ellsworth's talk at Stanford University. She explains why they are so important. Great Story.

http://8bit.dk/jeri/jeri_ellsworth_talk_stansford_uni.avi

Very good!

[Zac67]

4.78V on the A501 might be a bit low; if you measured the PS input it's way low - why don't you juice up the PS .2 or .3V?

If it's not voltage I'd guess one of the RAS, CAS or WE lines is dead, so the RAM can either not be addressed or not be written to...

Yes, dead RAMs most often get warm pretty fast.

[Chain]

Nice macrophoto
...and this is very oln 150ns chips

[orange]

I've measured again, its 4,84 V on all chips. They don't get hot but I don't know for how long A500 should be on.

BTW, if just one of them is faulty none works?

[Zac67]

Still not working?

Voltage is not really awsome, but should work.

Well, if one chip is bad, Amy might see the error on memory sizing and doesn't add the memory at all. More probable though is the missing _EXRAM signal on pin 32. Is that grounded when the expansion is plugged in (I assume it's a non-ECS 500 w/ 512 KB chip and 512 KB pseudo fast ('Ranger')).

PS: bad chips get hot VERY fast - IF they get hot