Need help/suggestions on a dead C4P-MF

dave
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Re: Need help/suggestions on a dead C4P-MF

Post by dave » Mon Jul 03, 2017 6:59 pm

Hmm. Previously I had installed a plugin that automatically scaled photos for display, but did not change their file size. When I set up the site on Amazon EC2, I did not install any plugins. I'll take care of that when I have a chance.

I had forgotten that I need to adjust the upload file size from the pitiful default. I removed the file size restriction.

Thanks,

Dave

Andis
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Joined: Sat May 13, 2017 8:15 pm
Location: Rocky Mountains, USA

Re: Need help/suggestions on a dead C4P-MF

Post by Andis » Mon Jul 03, 2017 11:13 pm

Thanks Dave.

BTW, did you get my 2 PMs, sent around noon on Sunday, July 2, regarding photo permissions? I'm only asking on the board as the behavior of the PM system has changed (at least for me). It used to be when i sent a PM, the PM was transferred to the 'Sent' folder when it was submitted. The ones I sent you are sitting in the 'Outbox' folder but show as 'Sent: Sun Jul 02, 2017 11:50 am', etc....

Thx Again.
C4P-MF, 540 RevB-1/542, 527 w/12K, 527-RevA w/24K, 505-RevB

Andis
Posts: 32
Joined: Sat May 13, 2017 8:15 pm
Location: Rocky Mountains, USA

Re: Need help/suggestions on a dead C4P-MF

Post by Andis » Mon Jul 03, 2017 11:26 pm

Anyways, back to the project. I disconnected the 505 and 527 memory expansion board from the PSUs and the fuse still blew. Then I disconnected the 505 and 527a 'standard memory board from the PSUs and the fuse still blew. Then I disconnected the Backplane I/O board (can't remember the number of it) and of course the fuse blew, sigh.

Finally, err there is no finally, ran out of fuses! The only thing left connected is the 120 volt Fan. It has always started spinning up for 1/2 a sec before the fuse going. So will check that when i get another supply of fuses (I should have known better than to only get 8, it probably costs me "24 fuses in gas" to make the round trip... If it turns out to be the fan you'll hear my scream across the ether :lol: . Actually, if it does turn out to be the fan, it was worthwhile to replace the PSU caps and voltage regulators regardless. The caps were looking pretty bad.
C4P-MF, 540 RevB-1/542, 527 w/12K, 527-RevA w/24K, 505-RevB

dave
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Posts: 426
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Re: Need help/suggestions on a dead C4P-MF

Post by dave » Tue Jul 04, 2017 4:39 pm

Andis wrote:
Mon Jul 03, 2017 11:13 pm
Thanks Dave.

BTW, did you get my 2 PMs, sent around noon on Sunday, July 2, regarding photo permissions? I'm only asking on the board as the behavior of the PM system has changed (at least for me). It used to be when i sent a PM, the PM was transferred to the 'Sent' folder when it was submitted. The ones I sent you are sitting in the 'Outbox' folder but show as 'Sent: Sun Jul 02, 2017 11:50 am', etc....

Thx Again.
Just got the PM's. I haven't been able to check in the past couple of days.

I have struggled with phpBB's permission system, just to get guests to be able to see the forums. I hadn't realized the attachments are not visible to guests until you pointed it out. It seems that the permission settings should allow viewing them, but I'm obviously overlooking something.

I still have all the files from the original board, so images should not be lost. I will create a new forum for board problems, so hopefully we can use that as a primitive issue tracker. It looks like I will have to go through each post in each forum to look for broken links. If anyone is interested in taking on one or more forums to inspect, go ahead and post your intent in a thread in the new "Forum Bugs" section.

If anyone is familiar with phpBB and can advise me on how to fix some of the bugs, I'd be grateful.

Hopefully we will be back to normal soon.

Dave

Andis
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Joined: Sat May 13, 2017 8:15 pm
Location: Rocky Mountains, USA

Re: Need help/suggestions on a dead C4P-MF

Post by Andis » Fri Jul 07, 2017 2:45 am

Hey All, I have a question regarding if a poorly connected fan could cause a fuse to blow in my C4P (that's the basic short question if you don't want to read further :D). I really shouldn't be in a position to have ask this question, but I wasn't meticulous enough in my last step ( as described in my last post above), where I was going to check if the fan was blowing the fuses.

Everything but the fan was disconnected and I blew a fuse, so I figured at least one issue was the fan, maybe not the 'fixed' PSUs at all. I pulled the fan and it looked like there was a bad connection on one side the fan connections. The connections were very thin wires coming out of the motor and were just (supposed to be?) tightly wrapped around the solid wire 120 V power wires (no solder or lugs, just a wire clamp basically holding the feed wires). What I realized after fixing that issue is, that when I initially blew the fuse during this phase of testing, there was a SLIGHT possibility that the the Hot Lead wire coming off power switch 'toggle' could have possibly grounded out (it had been already been disconnected from the PSU). I don't think this is the case, but cannot be 100% positive.

So, my question is, if a fan that wants to draw .2 amps, but is getting starved of current (say 10 to 100 times less than required) , could it blow a 2 amp fuse? I don't know enough about electronics to answer that question. I DO know that the fan, reconnected firmly now, is now putting out WAY more CFM , I'd say easily 10 times the amount of air flow as before just by feeling the 'exhaust'. For all i know it could be 50 times more. The air flow went from where I could barely feel the air flow to a significant amount of air being moved (more than any fan I've ever had on any of my later PCs).

Sorry to ask such a simple question, but if the issue could really just have been the fan connection, I would go through the bother of re-installing the 'fixed' PSUs, which would take a while, but could turn out to still have issues. If the fan couldn't have caused the blown fuse, then the 'fixed PSUs are bad and I would go straight to dropping in a replacement PSU, which is much easier and faster.

Thanks In Advance. Cheers, Andis
C4P-MF, 540 RevB-1/542, 527 w/12K, 527-RevA w/24K, 505-RevB

dave
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Re: Need help/suggestions on a dead C4P-MF

Post by dave » Fri Jul 07, 2017 5:33 pm

I am not home so can't check directly, but isn't the fan hooked up to the 120VAC in parallel with the power supply and fuse? If so, it should not affect the fuse at all.

Or is it hooked up after the fuse, in parallel with the power supply? In that case, a short could blow the fuse, but a poor or open connection would cause the fan to not operate, but would not blow a fuse.

You can confirm by disconnecting the fan entirely. I suspect you'll still see a blown fuse, which would implicate the power supply.

Keep us posted.

Andis
Posts: 32
Joined: Sat May 13, 2017 8:15 pm
Location: Rocky Mountains, USA

Re: Need help/suggestions on a dead C4P-MF

Post by Andis » Sat Jul 08, 2017 9:53 pm

Thanks for your response Dave. The fan is hooked up to the 120V after the fuse. It was not the fan, though i did resolder the tiny fan wires to what I originally thought was a solid core 120V feed wire. It turned out to be the PSU, even after the Cap and Voltage regulator replacement. I'm just going to drop in a new switched PSU I have, for now at least...

The fan wires were just basically attached to the feed wires by 'tinning' the end of the stranded wire while the tiny fan wire was inserted into the stranded wire. It was just a day I shouldn't have worked on the repair. The fan does move air better after 're-tinning' the connections but not as much of an improvement as I thought, I was just feeling the air flow flow on wrong side of the fan, :roll: . The solid core wires were just tinned, I must have accidentally shorted the hot 120 V lead coming off the power switch to the C4P frame and blew the fuse that way. That'll teach me not to work on the C4P when I am tired!!!! Jeez.
C4P-MF, 540 RevB-1/542, 527 w/12K, 527-RevA w/24K, 505-RevB

Andis
Posts: 32
Joined: Sat May 13, 2017 8:15 pm
Location: Rocky Mountains, USA

Re: Need help/suggestions on a dead C4P-MF

Post by Andis » Fri Jul 14, 2017 9:01 pm

The Good, the Bad, and the Ugly

The good news is I finally got some time and I dropped in the 100 watt switched PSU and fired up the machine. It runs sweet and cool, and I think the graphics look better with the new PSU.
0712171809.jpg
0712171806.jpg
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The bad news is that when my original PSU blew, Track0 on my 'daily use disk' got corrupted. I tried to get it fixed by using the TRACK0 copy program but didn't have much hope. Looking further into that issue (on my 'Backup, write-protected disk'), I realized that my Track 13 has 8 pages. The program is supposed to be only 5 pages long. So now I'm going to have to figure out how to get Track13 onto a disk. Does anybody have the Assembly Code for what resides on Track 13? I'd be more than willing to type the whole thing in and save it off.

The ugly. I did hook up the new PSU using a longer hex head screw to connect to one tiny piece of the PSU, and even re-arranged the Zip-Lock blocks so the PSU sits tight against them. So there is some air circulation all around the PSU. However, I had to stabilize the PSU with a wire across the connector end of the PSU. I do plan on fixing this with some real 'metal something' to connect from old PSU base to the screw holes in the new PSU.
0712171806a.jpg
0712171807.jpg
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If it wasn't for the Track 0 issue, I'd be ecstatic! I REALLY don't want to use my one last bootable disk on a daily basis. I kept the old 'fixed PSUs' and will see what's going on with those later if I get the time.

Thanks everybody for all their support !!!
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C4P-MF, 540 RevB-1/542, 527 w/12K, 527-RevA w/24K, 505-RevB

MK14HAK
Posts: 264
Joined: Wed Mar 16, 2011 1:49 am
Location: New Zealand

Re: Need help/suggestions on a dead C4P-MF

Post by MK14HAK » Fri Jul 14, 2017 10:33 pm

Hey thanks for all the great photos Andy. Great your finally up and running.
I use this version of the TK0 Util that is also compatible with Cegmon. The $0200 load address is a pain in the original as it wont survive a reset. This is a relocated version at $300.
If it doesnt work for you it may be a screen handler issue and ill have to hunt down yet another haked version I have somewhere.
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600RevB:16K,2MHz,64x32,470,CEGMON
SuperKit:502,540B,542B,CEGMON, 8" and 5" FDDs
Cards:PE IO,6522 D-A-D, AY3-8910,ProgramGraphics,Color,UK101
WIP:Archive/Restore Util,HexDOS,FDD Emulator

Andis
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Location: Rocky Mountains, USA

Re: Need help/suggestions on a dead C4P-MF

Post by Andis » Wed Sep 20, 2017 5:34 pm

Well, I finally got around to firmly attaching the new PSU. It turns out the Meanwell PSU is a pretty good 'drop in' replacement for the old C4P PSUs. One end of the PSU has a notch in it, to which you can attach one of the existing C4P hex screws to (need to buy a longer hex screw though and an extra nut). Then you can buy a 'post to beam' deck strap, cut it with tin snips (on the red line in a photo below), put a 90 degree bend in it and the holes in the new bracket mount line up perfectly with another existing C4P hex screw and a PSU screw hole . Didn't have to drill any new holes or do any unusual attachment.

Thanks for all the help guys. Now comes the spooky part, I'm slowly going to get up to letting everything go through a 24 hour burn in. I have already used it for 3 hours straight and the top the of C4 is only slightly warm. The floppy disk actually runs warmer.
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PSU_Mount.jpg
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PS_2_Mounts.jpg
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C4P-MF, 540 RevB-1/542, 527 w/12K, 527-RevA w/24K, 505-RevB

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