Without +12 and -5 the lower ram can't work properly, +12 is the 4116's supply voltage. And as soon as you notice those voltages are missing do not power on again because every time it runs without those voltages the lower ram can be easliy damaged. Fix the +12 and -5 before doing anything next time. Switching it on several times even though you knew +12 and -5 were missing was really tempting faith, you got very lucky you didn't damage the 4116 in the end.
Not something I would normally do. I knew that the owner had already powered it up to test it though, so any damage was likely already done. I was very surprised when the ram survived too!
Hi. Just found your channel, and I'm loving it. I'm an old Spectrum enthusiast ever since I got my first one in 1984. Anyway, my minor gripe is that those variable resistors you kept mentioning are variable capacitors. But never mind. Fascinating video and fascinating channel. Thanks.
Thank you! Ah! I've had someone else say exactly the same thing. I would urge you to go and check the schematics. There are two variable capacitors on issue 2 motherboards that control the dot crawl, and below those are two variables resistors that control the colour balance. 😄
I agree Lee! Don’t just change caps Willy Nilly most times they are good even when they are a bit out of spec they are generally there to just reduce ripple a slightly smaller or larger will just take care as well or to decouple the DC component that doesn’t require tight specs either. And filters if the knee is a few Hz left or right, nobody notices that - especially not with out old GenX ears that were damaged long ago with walkmans and boom boxes and screaming lead guitars anyways 😂
Cool device, I can normally tell you what is wrong with a specky from what is on the screen, even with the cart in I said TR4 (I started fixing speckys when they were current, showing my age!). This device would come in useful for those repairs that put up a fight (it you know what I mean). You’re a better man than me, I could not function without coffee! Good Video as per always.
@@MoreFunMakingIt Yes, it does not take much to kill a 4116 RAM chip. I did once have a come back on a TR4 replacement. It was running perfect in the workshop, but a week later it came back with a stability issue, that turned out to be a lower RAM chip.
That's a great tester. Could the board be modified to add test points before the resistors so you don't have to bend them? (I am no expert, it might be a stupid/impractical suggestion)
Well, I'm with you on 2:23, even if not 2:25. :) Why are hot drinks a thing? I don't honestly grok it. :) (Well, OK, maybe a hot chocolate every now and then on a cold day, but in general? no thanks!)
@@MoreFunMakingIt I'm unfamiliar with lemsip, though I will admit to having a "tea" of ginger, lemon, and honey (and no actual tea involved) from time to time, and that can be good.
Great vid as always Lee and just to let you know, your in good company as I also do not drink hot drinks. Never have, except maybe a very infrequent hot chocolate and hey I'm not odd 😅😊😂
@@ZombieVision oh I see! Sadly I can't change the website donations methods. I'm no expert, but aren't temporary debit cards a thing? Or even virtual ones? Wish I could help more
I wonder what the “green plastic charge” idiots in my country will do if they say all those nicely separate baggies. Probably charge the buyer 50p per baggie 😂it’s genuinely a very low level way for people to start doing kits. For us experienced old folks it doesn’t really matter but for newcomers this really is convenient and I still love convenient too 😂
487 😄
And writing down right now: will order green boards for the DIY kits, and adding that as an option to the product offers.
But black looks so much nicer 🤣
Without +12 and -5 the lower ram can't work properly, +12 is the 4116's supply voltage. And as soon as you notice those voltages are missing do not power on again because every time it runs without those voltages the lower ram can be easliy damaged. Fix the +12 and -5 before doing anything next time. Switching it on several times even though you knew +12 and -5 were missing was really tempting faith, you got very lucky you didn't damage the 4116 in the end.
Not something I would normally do. I knew that the owner had already powered it up to test it though, so any damage was likely already done. I was very surprised when the ram survived too!
Excellent video as always! Thanks for the shout-out, and I hope the charity drive goes great. Glad you liked my mod. Thanks for sharing
Thanks again!
Good stuff as always, it's all coming together!
I love it when a charity fundraising event comes together. _smiles toothily around large cigar_
Nice build Lee, please re-solder the resistors to lie flat! 😮😮
Nope! 😆
Hi. Just found your channel, and I'm loving it. I'm an old Spectrum enthusiast ever since I got my first one in 1984. Anyway, my minor gripe is that those variable resistors you kept mentioning are variable capacitors. But never mind. Fascinating video and fascinating channel. Thanks.
Thank you!
Ah! I've had someone else say exactly the same thing. I would urge you to go and check the schematics. There are two variable capacitors on issue 2 motherboards that control the dot crawl, and below those are two variables resistors that control the colour balance.
😄
@@MoreFunMakingIt I stand corrected. 😉
"I'm not going to do a montage this time" then proceeds to do a montage 🤣
Never trust a TH-camr!
I agree Lee! Don’t just change caps Willy Nilly most times they are good even when they are a bit out of spec they are generally there to just reduce ripple a slightly smaller or larger will just take care as well or to decouple the DC component that doesn’t require tight specs either. And filters if the knee is a few Hz left or right, nobody notices that - especially not with out old GenX ears that were damaged long ago with walkmans and boom boxes and screaming lead guitars anyways 😂
Its also a lot less work 😆
Very handy cartridge! :)
👍🙏❤
I love it! So much better than what I was using
What a fun kit!! I hope to build a ZX Spectrum one day so I look forward to your upcoming video. :)
Thank you Merlin! Was great fun putting the Harlequin together. The OG 48k is a bit more fiddly!
Change the 7805 for a switch mode regulator, then that heatsink won't overheat the nearby caps.
Cool device, I can normally tell you what is wrong with a specky from what is on the screen, even with the cart in I said TR4 (I started fixing speckys when they were current, showing my age!).
This device would come in useful for those repairs that put up a fight (it you know what I mean).
You’re a better man than me, I could not function without coffee!
Good Video as per always.
Cheers! I was really surprised that the missing voltages didnt damage the lower ram!
@@MoreFunMakingIt Yes, it does not take much to kill a 4116 RAM chip. I did once have a come back on a TR4 replacement. It was running perfect in the workshop, but a week later it came back with a stability issue, that turned out to be a lower RAM chip.
Finally got off my bottom to sub, thanks for this 🙂
Woohoo! Welcome aboard 😁
Got to get me one... 👍
Yes!
Another great video. Niiice 😊
Thank you RCR! 😁
@@MoreFunMakingIt What microphone do you use? The audio is always so crisp
That's a great tester. Could the board be modified to add test points before the resistors so you don't have to bend them? (I am no expert, it might be a stupid/impractical suggestion)
I'm sure it could. It is nice to have something to hook a probe onto though, keeps your hands free
I'm really excited to bid.... Tho I have a bad feeling it's going to get v high v quickly !
I hope so!!!
@@MoreFunMakingIt Of course!
Well, I'm with you on 2:23, even if not 2:25. :) Why are hot drinks a thing? I don't honestly grok it. :) (Well, OK, maybe a hot chocolate every now and then on a cold day, but in general? no thanks!)
I'm OK with lemsip. But tea? Coffee? Why?
@@MoreFunMakingIt I'm unfamiliar with lemsip, though I will admit to having a "tea" of ginger, lemon, and honey (and no actual tea involved) from time to time, and that can be good.
Looks like serial number 487 or 497 to me
Thanks!
Now. I have this pain in my ankle...
Great vid as always Lee and just to let you know, your in good company as I also do not drink hot drinks. Never have, except maybe a very infrequent hot chocolate and hey I'm not odd 😅😊😂
I dont think Im odd. But there have been comments 😆
Brilliant video but you sunk my battle ship with all you D1 ,D2......
Ah, the old tactic of lining all the ships up on a single line! 😆
how does this one compare to mine ?
We can talk about that on the stream tonight!
Do you know when these diagnostic boards will be available and roughly the cost?
Hi! I forgot to put the link in the description. Fixed that now. They are also available on ZX Renew in the UK
Hello Lee! I would like to make a donation. But it's not possible to pay with PAYPAL. What now?
I really don't know. Do you know anyone with PayPal access that could do it for you?
@@MoreFunMakingIt I do have a PayPal account by myself. But on the donation site it's not possible to pay with paypal. There is no PayPal button.
@@ZombieVision oh I see! Sadly I can't change the website donations methods. I'm no expert, but aren't temporary debit cards a thing? Or even virtual ones? Wish I could help more
I wonder what the “green plastic charge” idiots in my country will do if they say all those nicely separate baggies. Probably charge the buyer 50p per baggie 😂it’s genuinely a very low level way for people to start doing kits. For us experienced old folks it doesn’t really matter but for newcomers this really is convenient and I still love convenient too 😂
I will recycle them eventually. 🤣
@@MoreFunMakingIt I will tell my governmental idiots this. Thanks for the suggestion 😂
Thank you. 🙏
OneLove 🔴🟡🟢🔵
497?
Yeah, for sure.
You must also be a doctor 😁
@@MoreFunMakingIt I though this was the normal way of writing a 4. How do you write that digit?
@@MoreFunMakingIt teacher.. lol
You have friends???
Do they count if I pay them an hourly rate?
@@MoreFunMakingIt ...that means something else