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Everex Step Mega Cube
- Thread starter Shadow Lord
- Start date
Chuck(G)
25k Member
About all I can say now, is that 2-lead component attached to the heatsink is a thermistor or temperature controller--it's hooked in series with the fan. So it really has nothing to do with the lack of +/-12. As for the rest, it'll take a a lot of staring to reconcile the views into something coherent.
Shadow Lord
Veteran Member
O.k. Once again thanks for any and all help. If you want a particular view or specific pic I am happy to post them.
Shadow Lord
Veteran Member
Unknown_K,
While I try to sort out the PSU issues I did some research on the lithium ion CMOS battery. It is a TADIRAN TL-5242/W and blessed be it is carried at the local rat shack! So the CMOS battery should not be an issue! Did you see any other batteries that may require changing on the pictures of the MB I posted? Thanks!
While I try to sort out the PSU issues I did some research on the lithium ion CMOS battery. It is a TADIRAN TL-5242/W and blessed be it is carried at the local rat shack! So the CMOS battery should not be an issue! Did you see any other batteries that may require changing on the pictures of the MB I posted? Thanks!
What is that big chip under the MOSEL MS6264L-10PC (that is a CMOS SRAM chip I think, next to the BIOS chips)
Shadow Lord
Veteran Member
Do you mean the UMC Chip? It is a UMC UM82C452L. On a huge leap of faith from me I believe it is a Serial Port/Parrallel port controller. I say this because I saw the same chip on an stand alone ISA ser/pll port card and it is located next to the connectors for the ser/pll ports on the MB.
Okay I found the data sheet for the UMC UM82C452 and it is a single chip multi-io solution.
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Shadow Lord
Veteran Member
OK the "new" PSU arrives today. Lets see if this bad boy will post!
Shadow Lord
Veteran Member
Well, more good news and bad news:
Good news: The new PS arrived. It is a REV A ver a REV 3 which is in the cube. I opened it up and on the first glance all looks good. Two boards in the PS just like mine. The green PCB is a REV 9 just like mine. A bit of closer inspection and....
Bad News: I see minor differences (a missing transistor on one of the heat sinks) and major difference in the wire color coding. No yellow or black wires. Instead I have Brown, Grey and Red. The grey is acting like the Neutral (black wires), the red is +5V but the brown carries +8, huh? Anybody familiar with this? Also although it uses the 12 pin molex the wires are arranged differently (even neutral and +5v) then the one's on my PSU.
Well, needles to say I did not connect this to my MB but I did put the "new" green PCB in my PSU and lo and behold the PSU fan came on when I turned on the system. So, the green pcb is definitely the problem. Questions:
1. Anybody know what this PSU could be for?
2. Could the +8V be controlled from the upright PCB?
3. If the PSU is supplying +8V why is the 12V DC fan spinning at what looks like top speed?
BTW: The +8V lines are coming from areas on the PCB marked as +12 on the PCB.
Good news: The new PS arrived. It is a REV A ver a REV 3 which is in the cube. I opened it up and on the first glance all looks good. Two boards in the PS just like mine. The green PCB is a REV 9 just like mine. A bit of closer inspection and....
Bad News: I see minor differences (a missing transistor on one of the heat sinks) and major difference in the wire color coding. No yellow or black wires. Instead I have Brown, Grey and Red. The grey is acting like the Neutral (black wires), the red is +5V but the brown carries +8, huh? Anybody familiar with this? Also although it uses the 12 pin molex the wires are arranged differently (even neutral and +5v) then the one's on my PSU.
Well, needles to say I did not connect this to my MB but I did put the "new" green PCB in my PSU and lo and behold the PSU fan came on when I turned on the system. So, the green pcb is definitely the problem. Questions:
1. Anybody know what this PSU could be for?
2. Could the +8V be controlled from the upright PCB?
3. If the PSU is supplying +8V why is the 12V DC fan spinning at what looks like top speed?
BTW: The +8V lines are coming from areas on the PCB marked as +12 on the PCB.
Did you check the model numbers on both PS to make sure they were the same? You never know on old non working gear if somebody was swapping parts between multiple machines, could not get them to work, and just sold it as is.
There were a few versions of that machine I would think, maybe the wiring changed a little between versions.
There were a few versions of that machine I would think, maybe the wiring changed a little between versions.
Shadow Lord
Veteran Member
Unknown_K the PS revisions are not the same. I bought the new PSU because it had the same power characteristics as the Everex board and I was hoping that AMS used the same boards and mounted them differently, which they did. Unfortunately, they also made some small electrical changes!
Shadow Lord
Veteran Member
O.k. well it seems as if this PSU is bad too. It is supposed to deliver +5V and +12V but I am getting +5V and +8V. Interstingly the -12V line does give -12V.