wyerd #1 Posted January 16, 2015 My PEB is dead. I just fitted a CorComp RS232 card I won on eBay over the weekend. Switched on the power, there was a dull thud sound and nothing. Removed all the cards and checked the fuse on the back which looks ok, dead as a Dodo. I need some help to revive it! Is the PSU completely dead??!! Don't understand why this has happened. Thanks, Dave. Quote Share this post Link to post Share on other sites
+Ksarul #2 Posted January 16, 2015 Sounds like it blew the fuse in the middle of the transformer windings. . .I've seen a tutorial online on how to perform the necessary surgery to replace it, although I don't remember where at the moment. Quote Share this post Link to post Share on other sites
wyerd #3 Posted January 16, 2015 MainByte mentions an internal fuse at the bottom of the page here http://mainbyte.com/ti99/peb_pow/peb_pow.html I thought as mine has the fuse at the back, there wasn't another one. I'll start disassembling it. Thanks. Quote Share this post Link to post Share on other sites
wyerd #4 Posted January 16, 2015 I had removed the original fan a while ago and replaced it with a quieter PC one, but when I re-connect the original, it works, so it must be the transformer fuse. The question is, why did it blow in the first place? Was adding another card too much for it as I'm running 2 drives? Should I consider the 2 Amp power upgrade? Quote Share this post Link to post Share on other sites
wyerd #5 Posted January 16, 2015 It's a messy job finding the fuse. Looks like it's blown. Anyone on here replaced one of these before as I could do with a few tips on how it's done! Quote Share this post Link to post Share on other sites
+OLD CS1 #6 Posted January 16, 2015 Before you do, you might want to figure out why it blew in the first place. I would not replace that fuse, but rather bypass it and splice in a fuse and holder somewhere up the line OUTSIDE of the transformer. I have not looked so the Mainbyte article might recommend the same thing. 1 Quote Share this post Link to post Share on other sites
+InsaneMultitasker #7 Posted January 16, 2015 I had removed the original fan a while ago and replaced it with a quieter PC one, but when I re-connect the original, it works, so it must be the transformer fuse. The question is, why did it blow in the first place? Was adding another card too much for it as I'm running 2 drives? Should I consider the 2 Amp power upgrade? The card may have been the culprit. Did you purchase it from someone who jumpered it internally for use with a PC power supply? You might want to crack the RS232 card case open to inspect the regulators. Also, is this a CorComp metal clamshell or was a TI clamshell used? Quote Share this post Link to post Share on other sites
atrax27407 #8 Posted January 16, 2015 It could also have been modified for use with a Rave system. Quote Share this post Link to post Share on other sites
sparkdrummer #9 Posted January 16, 2015 +1 with OLD CS1 I have made this repair on one of my other Pebs and I outboarded the fuse. It is not a fun job and those wires are teeny. conTInuing, -Ralph... Quote Share this post Link to post Share on other sites
wyerd #10 Posted January 16, 2015 Thanks for the advice guys. The card was sold without a clamshell and there don't appear to be any mods to it either. This is the eBay listing http://www.ebay.com/itm/141530969665?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT An external fuse is a great idea. Where would you recommend I get the parts from which I assume would be:- 3A fast blow fuse Fuse holder with wiring Quote Share this post Link to post Share on other sites
wyerd #11 Posted January 16, 2015 I forgot to mention that I put the card in a TI metal clamshell that I had spare. Quote Share this post Link to post Share on other sites
+Ksarul #12 Posted January 17, 2015 That TI clamshell has some projections that probably shorted your 5V straight to ground. . . .it may have also damaged the card, so look carefully at the components on it--and look for a possible arc point. Quote Share this post Link to post Share on other sites
wyerd #13 Posted January 17, 2015 That TI clamshell has some projections that probably shorted your 5V straight to ground. . . .it may have also damaged the card, so look carefully at the components on it--and look for a possible arc point. Ah...........I wasn't aware of that.......( goes off and bangs head against a wall!! ) This looks like the projection that you're talking about You can see the impression it made on the card right on the power lines to the voltage regulator..........BANG....... I'll have to re-title the topic to "I killed my PEB by assuming all clamshells are the same". 1 Quote Share this post Link to post Share on other sites
wyerd #14 Posted January 17, 2015 I've found a replacement transformer fuse http://www.ebay.com/itm/5x-BUSSMANN-SCHURTER-GMA-3A-250V-Fast-Blow-GLASS-fuses-5X20mm-F3A-3-Amp-/161120425114?pt=LH_DefaultDomain_0&hash=item258386949a but not sure what type of holder to use. Is this side of the transformer high voltage? Quote Share this post Link to post Share on other sites
Omega-TI #15 Posted January 17, 2015 Dude, hopefully it's just the fuse and you can grind down that culprit and try again. 1 Quote Share this post Link to post Share on other sites
wyerd #16 Posted January 17, 2015 Found that Lowes stock the fuse. http://www.lowes.com/pd_536982-73694-BP/AGC-3-RP_0__?productId=50193543&Ntt=3+amp+fuse&pl=1¤tURL=%3FNtt%3D3%2Bamp%2Bfuse&facetInfo= Quote Share this post Link to post Share on other sites
Omega-TI #17 Posted January 17, 2015 Did you get it fixed yet? Quote Share this post Link to post Share on other sites
wyerd #18 Posted January 17, 2015 Did you get it fixed yet? I'll hopefully fix it tomorrow if I can get the fuse from Lowes. I'm just not sure what fuse holder to get. I'd appreciate any pointers on that. Quote Share this post Link to post Share on other sites
Omega-TI #19 Posted January 17, 2015 I prefer this type myself, it's like what comes on the original P-Box. If you blow it in the future, you'll not have to take the box apart. You'll need a good drill bit to put a hole in that metal though! 1 Quote Share this post Link to post Share on other sites
wyerd #20 Posted January 17, 2015 What gauge wire should I be looking at? I'm new to the AWG format. Quote Share this post Link to post Share on other sites
kl99 #21 Posted January 17, 2015 sorry to hear about your issue. I thought on bidding on this card myself. There is also interesting notes on PEB/fuse/transformer here: http://www.nouspikel.com/ti99/pesurg.htm Quote Share this post Link to post Share on other sites
wyerd #22 Posted January 17, 2015 Bugger...... didn't work. Installed fuse and tested it without any cards. Same thud sound as I switched it on then nothing. Looks like the PSU circuit is fried somewhere. Anyone have a spare PSU they'd like to sell?? Otherwise it's a NOS PEB now at $140 odd dollars Quote Share this post Link to post Share on other sites
+OLD CS1 #23 Posted January 17, 2015 Anyone have a spare PSU they'd like to sell?? Otherwise it's a NOS PEB now at $140 odd dollars Bummer, man. Are there alternative PSUs that you can try now you have freed up that space? I have had the idea of replacing my PEB PSU with an ATX for a long time, but I have pretty much shelved that for more important things. As for the price, I found a Joy Electronics catalog sent to me back in 2001-ish listing PEBs for $200. Comparatively I do not guess $140 is all that bad. But, it is easy for me to say as I picked up my NOS PEB back when they were $89 each. Quote Share this post Link to post Share on other sites
Gazoo #24 Posted January 17, 2015 Bugger...... didn't work. Installed fuse and tested it without any cards. Same thud sound as I switched it on then nothing. Looks like the PSU circuit is fried somewhere. Anyone have a spare PSU they'd like to sell?? Otherwise it's a NOS PEB now at $140 odd dollars Install a PC power supply while you've got the thing open. It's worth the effort, and cheap. Gazoo Quote Share this post Link to post Share on other sites
wyerd #25 Posted January 17, 2015 Install a PC power supply while you've got the thing open. It's worth the effort, and cheap. Gazoo A quick Google on the subject suggests that the power regulator of the cards would have to be removed, and going on past experience, I don't want to mess anything else up! Quote Share this post Link to post Share on other sites