Crispy TIU'S

Easy fix if the case isn't too deformed, I have the banana plug assemblies.  I also have a couple of TIU cases from Rev. G dead TIU's.  When you replace them, make sure the nuts are tight on the lugs.

So far my TIU is fine, just a for-what-it's-worth here... I've tried several banana plugs over the years and these are the best I've found EZ-Hook 9202 R/B, nickel plated. They are quite sturdy, don't smash, flatten or loosen up with repeated use like many others do. They also fit very tightly in the jacks and stay that way. I was quite impressed with these compared to all the others I've tried, many of which were more expensive, gold plated, etc.  Unfortunately, the price has gone up some, they were only around $4 a pair on my last purchase.

For binding posts (dual jacks), I've been eyeing the Keystone 7109. Looks like a nice one, nickel plated, 10-32 threads, 30 amp rating and appears to be of good quality.  Also a bit pricey, but cheaper than their gold plated model 4109.  Haven't tried these myself, but might have to order a couple to investigate. The ones I've used lately from ebay are ok, but the threads sometimes seem to strip fairly easily which makes me question the reliability of the connections. I've had a couple just strip out while tightening, for no appearant reason.

@rtr12 posted:

So far my TIU is fine, just a for-what-it's-worth here... I've tried several banana plugs over the years and these are the best I've found EZ-Hook 9202 R/B, nickel plated. They are quite sturdy, don't smash, flatten or loosen up with repeated use like many others do. They also fit very tightly in the jacks and stay that way. I was quite impressed with these compared to all the others I've tried, many of which were more expensive, gold plated, etc.  Unfortunately, the price has gone up some, they were only around $4 a pair on my last purchase.

For binding posts (dual jacks), I've been eyeing the Keystone 7109. Looks like a nice one, nickel plated, 10-32 threads, 30 amp rating and appears to be of good quality.  Also a bit pricey, but cheaper than their gold plated model 4109.  Haven't tried these myself, but might have to order a couple to investigate. The ones I've used lately from ebay are ok, but the threads sometimes seem to strip fairly easily which makes me question the reliability of the connections. I've had a couple just strip out while tightening, for no appearant reason.

If you need binding posts for your TIU, I have the OEM ones from dead TIU's.

Common problem when pulling alot of amps for a long period of time.  The nuts securing the wires from the board loosen, create a high resistance connection, overheat and melt.  Also common on the Z4000.  As a general rule, if I open one, I check all terminals.  I believe they are 7mm.

I had to replace 4 of them back in early 2022 that were as melted as yours. The hardest part was chipping off the melted base post  without totally destroying the tiu case.  On one particularly bad post, I needed a heat gun to soften the banana plug base in order to remove it. It’s been working great ever since I installed the new ones and even though I’ve tightened everything well, I try and check for melting or disfigured banana plugs at least once a month, since my subways run with lots of amps. Here is the after -

edit 5/27 - so, it’s been three days and no one noticed that the pic shows the lower left post installed backwards, LOL!  I had to reverse it right after I took this pic back in 2022.

Wow!  Loose connections that carry current are never a good thing.  Could folks avoid this possibility by wiring their TIUs in "passive mode?"

@gunrunnerjohn posted:

If you need binding posts for your TIU, I have the OEM ones from dead TIU's.

Thanks John I appreciate the offer, but my TIU is fine (so far, crossing fingers). I've checked the nuts inside a few times over the years, so far none have been loose. And those EZ-Hook banana plugs fit really tight and don't loosen up at all, even after repeated use.

The Keystone binding posts would be for other stuff, plus I'm quite curious about their quality. I sort of cobbled together a copy of the volt/amp meter box you made a while back, using some ebay binding posts I had.  They looked just like the ones in the TIUs and appeared to be of good quality.  That is until I installed them and tried to tighten the mounting nuts. Two posts stripped out when just barely snug, not even close to tight.  I've been looking for some better ones since then.

Check a Electrical Supply Business, either a brick and mortar or online. They deal daily with Contractors for Industrial, Commercial, and Residential uses, but most of them also take care of regular customers. They deal with top quality items. If they don't have binding posts in stock, I'm sure they can get them quickly from one of their business suppliers. Probably a bit more than from the A or the E, but you won't have to worry about quality if they'll hold up. Digi-Key and Mouser are just two names I've had great quick service from online companies. I also have one brick and mortar Electrical Supply Business if I need something quickly that's about a 15 mile round trip for me that also stands behind their products. Sometimes the cheapest price isn't the best quality. Sometimes you get what you pay for. Pay cheap, get cheap quality, pay more, get better quality that works for our needs and holds up much longer.😁

Digikey gets most of my orders, with Mouser getting orders for things DK doesn't have. Fortunately, DK usually has everything I need. The Keystone binding posts and EZ-Hook banana plugs I linked to above are both from Digikey.  The last couple of years I've cut way back on my ebay, amazon & aliexpress orders due to the 'get what you pay for' factor you mentioned.

You have to know what you're getting from AliExpress, not everything is YGWYP when compared to the major electronic supply houses.  I buy pre-fab cable assemblies with the 1.25mm and 1.5mm connectors and wires from AliExpress for a small fraction of what they'd cost at Digikey, I've been very happy with their quality.  I also buy stuff like the 1527 learning code transmitters & receivers there, they would be totally cost prohibitive from any US manufacturer.

Gunrunnerjohn, you are correct, you do need to know what you're getting, unfortunately not all of us are anywhere near as knowledgeable as you about what is good and what is not. You deal with that stuff everyday and we all certainly appreciate your willingness to share and help us all out. I've been burned by crap quality before on the A & E sites, so when I need something robust that will hold up to use I will buy from a Electrical Supply Business, obviously you probably buy more Electrical components in 2 weeks than I do in a year! As always, buyer beware! Thanks again for all your help and have a good day and weekend as we all remember all that died defending our freedom.

GRJ,  I still use Aliexpress & ebay, just not nearly as much as I used to. I did just order a bunch of misc. stuff from Aliexpress this week. It's all stuff I've never used before so we'll see how it goes quality wise when it arrives. I had a list from someone and it was all Aliexpress suourced so I just followed the list. Supposedly they had used it all before so hopefully it's all ok.

Of course as Gary says, you probably use more in a week or two than I do in a year. And you also have all the 'know how' necessary to go along with it!  I'm still lacking in that area by a LOT!

I'll certainly agree that stuff like binding posts, banana plugs, test leads, etc. are not something you want to buy from AliExpress or eBay.  I've tried that, and I burned the T-Shirt!